The Spine Journal - Articles in Press

Corpectomy versus discectomy for the treatment of multilevel cervical spine pathology: a finite element model analysis - Corrected Proof

2012-05-10

Abstract: Background context: After multilevel fusions, construct failure because of pseudoarthrosis and instrumentation complications is a well-recognized clinical problem. Little is known about the biomechanics governing the cervical spine after different anterior reconstruction techniques, specifically the number of bone grafts and screws used and whether discectomies versus corpectomies have been performed. A few research groups have compared the efficacy of corpectomy and discectomy procedures under common testing conditions; however, no quantitative stress measurements at graft–end plate and bone-screw interfaces have been reported to date.Purpose: To test the hypothesis that increasing the number of bone grafts and screws would yield a more stable construct and decrease the stresses at the graft–end plate and bone-screw interfaces.Study design: Stability of fusion constructs with three different multilevel reconstruction techniques.Methods: A previously validated C3–T1 intact finite element model was modified to evaluate three different anterior C4–C7 fusion models: a two-level corpectomy alone (one graft and four screws), a corpectomy-discectomy (two grafts and six screws), and a three-level discectomy alone (three grafts and eight screws). Two unicortical screws were placed parallel to the corresponding end plates inside the vertebral bodies—C4 and C7 for the corpectomy alone; C4, C6, and C7 for the corpectomy-discectomy; and C4, C5, C6, and C7 for the discectomy alone. Range of motion, graft stresses, end plate stresses, and bone-screw stresses were evaluated.Results: Although total construct motion decreased with an increasing number of bone grafts and screws, this was not significantly different between reconstruction techniques. Stresses in the bone grafts, end plates, and bone near screws decreased as a result of increasing the number of bone grafts and screws, thereby confirming the present study hypothesis.Conclusions: Although the chances of pseudarthrosis have been shown to be lower after multilevel cervical corpectomy versus discectomy, because of fewer bone-graft interfaces required for healing, this benefit should be weighed against the higher bone-screw stresses, operating time, blood loss, and costs associated with corpectomy. Future biomechanical studies focusing on corpectomy and discectomy procedures in similar testing protocols are warranted to compare the findings presented here.

Sacral sparing in SCI: beyond the S4–S5 and anorectal examination - Corrected Proof

2012-05-10

Abstract: Background context: Sensory and/or motor function sparing, including the S4–S5 spinal cord segment, is central to classifying neurologic impairment after spinal cord injury (SCI) using the American Spinal Injury Association Impairment Scale (AIS) grades within the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI). Within the ISNCSCI protocol, which is essential for both clinical and research purposes, assessing sacral sparing requires an anorectal and S4–S5 examination. However, in situations where these data are incomplete, the relationships between anorectal/S4–S5 examinations and functional preservation at more rostral sacral segments may be useful.Purpose: To evaluate whether slightly more rostral sensory and motor outcomes of the ISNCSCI can accurately predict caudal sacral sparing (S4–S5 dermatome sensation, “deep pressure” anal sensation [AS], and voluntary anal contraction [AC]).Study design: Retrospective analysis of the European Multicenter Study about Spinal Cord Injury database.Patient sample: One thousand four hundred sixty-seven AIS-A, AIS-B, and AIS-C subjects.Outcome measures: International Standards for Neurological Classification of Spinal Cord Injury examinations.Methods: The value of six factors (sensory preservation at S1, S2, and S3; motor preservation at S1; motor function at more than three segments below the motor level; and sensory function at more than three segments below the neurologic level) for predicting ISNCSCI sacral sparing measures (AS, S4–S5 dermatome sensation, AC) was evaluated. Combinations of the most promising factors were then evaluated for their ability to accurately predict the AIS grade.Results: Preserved sensation at the first sacral segment (S1S) provided good prediction (90.5%) of caudal sacral sensory sparing (ie, AS or S4–S5 sensation). Voluntary anal contraction was accurately predicted by preserved motor function within the first sacral segment (S1M) in 85.4% of cases. The alternate classification schemes evaluated for accurately predicting the AIS classification grade were S1S+S1M and S1S+motor preservation more than three segments below the motor level. The ability of these schemes to accurately predict AIS grades was stable over time but varied with the rostrocaudal level of spinal injury. For the initial baseline examination, the alternate classification schemes were accurate in ∼95% of cases for T2–T9 SCI, with slightly lower accuracy for cervical SCI (∼80%).Conclusions: There are close relationships between functional sparing at different sacral segments. These relationships can be used to estimate AIS grades when complete information about the anorectal and S4–S5 examination is not available. The accuracy of the classification remains stable over time, while the increased variability in lower levels of SCI, that is, lumbar injuries, emphasizes the importance of careful sacral examinations. The highly reliable predictive values of S1–S3 segments can complement conclusions from anorectal examinations if the latter are considered to be confounded or incomplete.

Dysphagia and soft-tissue swelling after anterior cervical surgery: a radiographic analysis - Corrected Proof

2012-05-07

Abstract: Background context: Dysphagia is common in the early postoperative period after anterior cervical discectomy and fusion (ACDF). Several mechanisms, including soft-tissue swelling, have been implicated as a cause of postoperative dysphagia.Purpose: To determine whether anterior soft-tissue swelling is greater in patients with postoperative dysphagia.Study design: Prospective cohort study.Patient sample: Forty-three patients.Outcome measures: Validated dysphagia questionnaire, lateral cervical spine radiographs.Methods: Patients undergoing one- or two-level ACDF using allograft bone and anterior instrumentation were enrolled. Baseline patient demographic characteristics and history were recorded. A dysphagia questionnaire, including a dysphagia numeric rating scale (DNRS; range, 0–10), was administered preoperatively and 2 and 6 weeks postoperatively. Lateral cervical radiographs were obtained preoperatively and 2 and 6 weeks postoperatively. The anterior cervical soft-tissue shadow width was measured at each level. Patients were divided into groups based on the 2-week dysphagia questionnaire: Group 1 (no symptoms/mild dysphagia) and Group 2 (moderate/severe dysphagia). Anterior soft-tissue shadow width at each level was compared between groups. Correlation was used to assess the relationship between DNRS and anterior soft-tissue swelling.Results: Forty-three patients (24 females; average age, 47.9) were enrolled. Fifteen patients had one-level and 28 patients had two-level ACDF. The anterior soft-tissue shadow width increased significantly from preoperative values at all levels except C1 at 2 and 6 weeks and C2 at 6 weeks. At 2 weeks, 18 patients had no symptoms/mild dysphagia (Group 1) and 25 patients had moderate/severe dysphagia (Group 2). The average DNRS was 1.1 for Group 1 and 5.3 for Group 2 (p<.001). This difference decreased by 6 weeks but remained significant. There were no significant differences in the soft-tissue measurements between groups at any level. There was no significant correlation between the DNRS and anterior soft-tissue swelling at any time point.Conclusions: There is a significant increase in anterior cervical soft-tissue swelling after ACDF. The width of prevertebral soft-tissue does not correlate with postoperative dysphagia.

Changes in red blood cell transfusion practice during the past quarter century: a retrospective analysis of pediatric patients undergoing elective scoliosis surgery using the Mayo database - Corrected Proof

2012-05-07

Abstract: Background context: Previous studies have demonstrated significant changes in red blood cell (RBC) transfusion practice over several decades.Purpose: The purpose of the present study was to ascertain changes in transfusion practice during a 25-year study epoch and determine whether these changes had any impact on the frequency of perioperative morbidity and mortality in pediatric patients undergoing major spine surgery.Study design: Retrospective chart review.Patient sample: Pediatric patients undergoing elective scoliosis surgery.Outcome measures: Impact of RBC transfusion on perioperative morbidity and mortality.Methods: Pediatric patients undergoing elective scoliosis surgery were stratified into one of two transfusion-related groups: 1975 to 1985 (ie, pre–human immunodeficiency virus screening, early practice group, n=177) or 1990 to 2000 (ie, recent practice group, n=192). Transfusion and perioperative outcome data were obtained from medical records. Red blood cell use was analyzed as a continuous variable and compared between groups using the Wilcoxon rank sum test, as were preoperative, postoperative, and discharge hemoglobin concentration. Age-adjusted data were compared between groups using chi-square or Fisher exact tests.Results: Patients in the recent practice group had significantly worse comorbid disease and more complex procedures compared with those in the early practice group. The percentage of patients in the recent practice group receiving allogeneic RBC transfusions was significantly less than the early group (37.5% vs. 89.8%, p<.001). Utilization of autologous RBC and intraoperative autotransfusion was significantly greater in the recent practice group (5.1% vs. 47.4% and 20.9% vs. 95.8%, respectively). Hemoglobin concentrations were significantly lower for all time periods in the recent practice group. There were no differences in major morbidity or mortality between groups.Conclusions: In this retrospective review, we report a significant change in blood management strategies in pediatric patients undergoing elective scoliosis surgery. We demonstrated a shift from utilization of allogeneic RBC transfusion toward preoperative donation and intraoperative autotransfusion. Although transfusion triggers were significantly lower in the recent practice group, we were unable to demonstrate a difference in major morbidity or mortality. Utilization of autologous RBC transfusion was safe and effective in reducing allogeneic RBC transfusions in this study. The advantages of autologous blood transfusion may be in preserving a relatively scarce resource (ie, allogeneic blood), rather than mitigating transfusion-related complications.

Quantitative assessment of abdominal aortic calcification and associations with lumbar intervertebral disc height loss: the Framingham Study - Corrected Proof

Pradeep Suri, David J. Hunter, James Rainville, Ali Guermazi, Jeffrey N. Katz — 2012-05-07

Abstract: Background context: Vascular disease has been proposed as a risk factor for disc height loss (DHL).Purpose: To examine the relationship between quantitative measures of abdominal aortic calcifications (AACs) as a marker of vascular disease, and DHL, on computed tomography (CT).Study design: Cross-sectional study in a community-based population.Patient sample: Four hundred thirty-five participants from the Framingham Heart Study.Outcome measures: Quantitative AAC scores assessed by CT were grouped as tertiles of “no” (reference), “low,” and “high” calcification. Disc height loss was evaluated on CT reformations using a four-grade scale. For analytic purposes, DHL was dichotomized as moderate DHL of at least one level at L2–S1 versus less than moderate or no DHL.Methods: We examined the association of AAC and DHL using logistic regression before and after adjusting for cardiovascular risk factors and before and after adjusting for age, sex, and body mass index (BMI).Results: In crude analyses, low AAC (odds ratio [OR], 2.05 [1.27–3.30]; p=.003) and high AAC (OR, 2.24 [1.38–3.62]; p=.001) were strongly associated with DHL, when compared with the reference group of no AAC. Diabetes, hypercholesterolemia, hypertension, and smoking were not associated with DHL and did not attenuate the observed relationship between AAC and DHL. Adjustment for age, sex, and BMI markedly attenuated the associations between DHL and low AAC (OR, 1.20 [0.69–2.09]; p=.51) and high AAC (OR, 0.74 [0.36–1.53]; p=.42).Conclusions: Abdominal aortic calcification was associated with DHL in this community-based population. This relationship was independent of cardiovascular risk factors. However, the association of AAC with DHL was explained by the effects of age, sex, and BMI.

The impact of discography on the surgical decision in patients with chronic low back pain - Corrected Proof

Svante Berg, Bengt Isberg, Anna Josephson, Mårten Fällman — 2012-04-23

Abstract: Background context: A reduced frequency of discographies might be the result of increasing concern with long-term effects of discography such as disc degeneration. More knowledge is needed in what patient discography is most likely to influence the surgical decision.Purpose: This study was aimed at highlighting how discography affects surgical decisions when performed on one of four different indications in a complicated subgroup of patients with chronic low back pain assumed to be associated with degenerative disc disease (DDD).Study design: Prospective before-after study to analyze how frequently a prediscography preliminary decision was changed and in what direction by adding information from discography in a subgroup of patients with DDD.Patient sample: One hundred thirty-eight patients admitted to a spine clinic more than 4 years with the DDD diagnosis (15% of all) were referred for discography because it was considered that medical history, clinical findings, and magnetic resonance imaging (MRI) were insufficient to make a final assessment on whether to propose surgery/recommend against surgery or what segments to operate on.Outcome measures: These were the recorded changes to prediscography preliminary decisions after information was added from discography.Methods: Before these patients were referred to provocative discography, the surgeon had to select one of four alternative questions/indications being the reason for the discography and choose what decision would have been made if discography would not have been available. The questions/indications were as follows: surgery decided discography to establish whether to treat adjacent segment as well (n=17); several segments degenerated on MRI, pain likely to be discogenic, discography to evaluate what segments to treat (n=56); uncertainty whether pain is discogenic but one suspected segment on MRI (n=38); uncertainty whether pain is discogenic and several segments degenerated in MRI (n=27); the decision after discography was then compared with the prediscography decision and the changes affected by the result of the discography were analyzed.Results: Changes were made to the prediscography decision in 71% of the patients in total. When the surgeon was assured that the pain was discogenic, one segment was added or subtracted in 58% of the patients compared with original prediscography decision. When the surgeon was uncertain if pain was discogenic, the final decision changed from surgery to no surgery in 8%, from no surgery to surgery in 42%, and in cases that were planned for surgery prediscography, one segment was added or subtracted in 17% of the patients. The more certain the surgeon was before discography that the patient's pain was indeed discogenic, the fewer changes between surgical treatment and no surgical treatment took place. The more uncertain the surgeon was before discography that the patient's pain was discogenic, the fewer changes in segments to treat took place in patients who went on to surgery. Changes of involved segments were made to all the 27 patients with a preliminary decision for surgical treatment of the L5–S1 segment solely. The corresponding figure for L4–L5 and L4–L5–S1 was 70% and 53%, respectively.Conclusions: A high frequency of decisions was altered in this group of surgeons when using discography as an additional examination in patients where uncertainty remains in how to treat after clinical examination, questioning, and MRI.

Dumbbell-shaped nonpsammomatous malignant melanotic schwannoma of the cervical spinal root - Corrected Proof

Hajime Yokota, Koichi Isobe, Masazumi Murakami, Hitoshi Kubosawa, Takashi Uno — 2012-04-23

Abstract: Background context: Melanotic schwannoma is a very rare tumor of Schwann cell origin, which can develop in various locations, similar to conventional schwannoma. This tumor has a malignant potential and therefore careful therapy is required.Purpose: To describe a case of melanotic schwannoma with a histopathologically and clinically malignant behavior.Study design: Case report.Methods: A 64-year-old man presented with sensory changes in his arm and gait disturbance. Magnetic resonance imaging revealed a dumbbell-shaped tumor at the left C7 spinal root, which was hyperintense on T1-weighted images and generally hypointense on T2-weighted images in comparison with conventional schwannoma; however, the peripheral zone was relatively hyperintense, and the central zone was hypointense like a target sign.Results: The tumor was partially resected and diagnosed to be nonpsammomatous malignant melanotic schwannoma. The patient experienced local recurrence and metastases to the bone and lung and finally developed quadriplegia. Radiation therapy failed to palliate the symptoms.Conclusions: Some melanotic schwannomas present with an aggressive behavior, which thus leads to poor prognosis. We should therefore be familiar with its characteristic clinical imaging and pathologic findings to provide a correct diagnosis and appropriate treatment for such patients.

Spinal cord compression by hematoma in the cervical ligamentum flavum: a case report - Corrected Proof

2012-04-23

Abstract: Background context: There have been some reports describing hematoma in the thoracic and lumbar ligamentum flavum, but there have been only three reports of hematoma in the cervical ligamentum flavum.Purpose: We describe another case of the ligamentum flavum hematoma in the cervical spine with a different feature of occurrence that required surgical treatment.Study design: Case report.Patient sample: Patient with ligamentum flavum hematoma in the cervical spine.Outcome measures: Preoperative magnetic resonance imaging and pathologic finding from operative specimen confirmed the diagnosis.Methods: A 69-year-old man insidiously presented with pain in his left upper arm and difficulty in left shoulder abduction. Neurologic examination demonstrated a cervical myelopathy with diffuse muscle weakness of left upper extremity and sensory disturbance. Imaging studies revealed a mass of high intense on T1-weighted images and isointense on T2-weighted images posterior to the dura at C4 lower end level. The patient underwent C4–C5 hemilaminectomy and the removal of the mass. The mass existed within the ligamentum flavum and was connected toward the pedicle like the beads of a rosary.Results: Histopathologic examination of the surgical specimen showed that the hematoma was present within the ligamentum flavum and contained macrophages that had phagocytosed red blood cells and hemosiderin. After surgery, the patients' symptoms immediately improved, and no recurrence was observed at 2 years postoperatively.Conclusions: We reported a very rare case of hematoma in the ligamentum flavum of the cervical spine that required surgery. Because the patient was without the history of trauma, it was suggested that the use of antiplatelet drugs was responsible for the occurrence of the disease.

Primary malignant peripheral nerve sheath tumor of the cauda equina with metastasis to the brain in a child: case report and literature review - Corrected Proof

Qiang Xu, Bing Xing, Xin Huang, Renzhi Wang, Yongning Li, Zhong Yang — 2012-04-23

Abstract: Background context: Primary intradural malignant peripheral nerve sheath tumors (MPNSTs) are extremely rare; only 23 cases have been reported in the English-language literature till now. No gold standard for treating primary intradural MPNSTs has yet been established.Purpose: To report a rare case of primary intradural MPNSTs in a child and review the literature pertaining to this rare disease.Study design/setting: Case report and literature review.Methods: We report our experience with one new case. An 8-year-old boy diagnosed with primary intradural MPNSTs underwent three surgical excisions and two rounds of radiotherapy; however, metastasis to the brain was found, and the boy died 16 months after the first surgery. We also review the literature pertaining to both MPNSTs in general and primary intradural MPNSTs.Results: Surgery is currently the mainstay of MPNST treatment. Radiotherapy and chemotherapy are of limited value in these tumors. Based on the review of the 24 cases described in the literature, including the present case, primary intradural MPNST is a very aggressive tumor with a very high recurrence rate even after gross total resection and with significant potential for leptomeningeal and systemic metastasis. The overall prognosis is very poor and seems to be worse than that of MPNSTs in general.Conclusions: Primary intradural MPNST is a very rare entity with a poor prognosis. Surgical tumor removal combined with postoperative high-dose radiation may be recommended. Chemotherapy is usually reserved for patients with disseminated metastases or tumors that are unresectable at the time of diagnosis.

Modic changes: prevalence, distribution patterns, and association with age in white men - Corrected Proof

Yue Wang, Tapio Videman, Michele C. Battié — 2012-04-20

Abstract: Background context: Suspected as a cause of back pain, Modic changes (MCs) have received increasing attention in spine research and care. Yet, epidemiologic knowledge of MCs based on the general population, which may provide an important clinical reference, is limited.Purpose: To investigate the prevalence and distribution patterns of MCs in the lumbosacral spine and their associations with age in a large population-based sample of men.Study design: An epidemiologic investigation of lumbar magnetic resonance images (MRIs).Patient sample: This study was based on the Twin Spine Study database, comprising a sample of male twins shown to be largely representative of the base Finnish population. Lumbar spine MRIs (1.5 Tesla Magnetom; Siemens AG, Erlangen, Germany) of 561 subjects (mean age, 49.8 years; range, 35–70 years) were included in the present study.Methods: For each spine, all 11 end plates (L1–S1) in the lumbar region were evaluated using both T1- and T2-weighted images to identify MCs, which were classified into Type 1, 2, 3, and mixed types. Furthermore, the number and location of MCs were recorded, as well as the anteroposterior (AP) and transverse sizes, to explore the prevalence and distribution pattern of MCs in the lumbar region and associations with age.Results: Modic changes were identified in 55.6% (312) of individuals and 13.5% (830) of end plates studied. Among these MCs, 64.2% (533) were Type 2, 16.0% (133) were Type 1, 18.1% (150) were Mixed Type 1/2, and the remaining 1.6% (13) were noted as Type 3 or Mixed Type 2/3. Modic changes were more common in the lower (74.5%) than in the upper lumbar region (25.5%), and 77.9% (642) of MCs presented in pairs at opposing end plates of a disc. Moreover, the specific type of MCs on opposing end plates was usually concordant. The presence of MCs in the lumbar region was associated with age (odds ratio=1.05–1.08 for each additional year of age, depending on type of MCs, p<.001). In addition, greater age was associated with a greater number of end plates affected and MCs of larger size (p<.001).Conclusions: Modic changes are common MRI findings in the lumbar spines of middle-aged white men, with Type 2 MCs predominating. Mainly present in the lower lumbar region, MCs tend to affect both end plates adjacent to a disc simultaneously, and they commonly involve the entire AP diameter of the vertebral end plate. The presence and size of MCs are clearly related to age, suggesting that aging or associated factors may play an essential role in the pathogenesis of MCs.

Duplicated odontoid process and atlas clefts associated to Klippel-Feil syndrome - Corrected Proof

2012-04-19

A 60-year-old woman, otherwise healthy, was admitted to the hospital for suspected craniocervical injury after an accidental fall. Results of physical and neurologic examinations were unremarkable, except for some bruising to the face. Computed tomography scan examination showed no signs of fracture or bleeding but revealed multiple abnormalities of the upper spine: multiple vertebral fusions (), paired odontoid process, and anterior and posterior clefts of the atlas (). A further physical examination revealed low hairline, short neck, and limited head rotation. Clinical and radiologic findings were consistent with Klippel-Feil syndrome associated to previously unreported craniocervical junction abnormalities .

Book and Media Review - Corrected Proof

Brynne E. Stainsby — 2012-04-13

This comprehensive text is a practical clinical resource for all spine care practitioners. With contributions from more than 50 international spine experts in a number of professions, Dagenais and Haldeman have created a thorough reference of the current scientific evidence in the management of low back pain. The authors aim to create a structured text with a format that allows for the comparison of different treatment approaches for low back pain and encourage evidence-based decision making by clinicians and policy makers alike.

Hypovitaminosis D as a risk factor of subsequent vertebral fractures after kyphoplasty - Corrected Proof

2012-04-12

Abstract: Background context: Over the past 20 years, methods of minimally invasive surgery have been developed for the treatment of vertebral compression fractures. Balloon kyphoplasty and vertebroplasty are associated with a recurrent fracture risk in the adjacent levels after the surgical procedure. In certain patient categories with impaired bone metabolism, the risk of subsequent fractures after kyphoplasty is increased.Purpose: To determine the incidence of recurrent fractures after kyphoplasty and explore whether the status of bone metabolism and 25-hydroxyvitamin D (25(OH)D) levels affect the occurrence of these fractures.Study design: Prospective longitudinal clinical study.Patient sample: Forty female postmenopausal women with primary osteoporosis and acute symptomatic vertebral compression fractures.Outcome measures: Identification of new vertebral fractures and documentation of indicators of bone metabolism.Methods: A total of ninety-eight kyphoplasties were performed in 40 female patients. Balloon kyphoplasty was performed on all symptomatic acute vertebral compression fractures. Age, body mass index, history of tobacco use, number of initial vertebral fractures, intradiscal cement leakage, history of nonspinal fractures, use of antiosteoporotic medications, bone mineral density, bone turnover markers, and 25(OH)D levels were assessed. All participants were evaluated clinically and/or radiographically. Follow-up period was 18 months.Results: The mean population age was 70.6 years (range, 40–83 years). After initial kyphoplasty procedure, nine patients (11 levels) (22.5% of patients; 11.2% of levels) developed a postkyphoplasty vertebral compression fracture. Cement leakage was identified in seven patients (17.5%). The patients without recurrent fractures after kyphoplasty demonstrated higher levels of 25(OH)D (22.6±5.51 vs. 14.39±7.47; p=.001) and lower N-terminal cross-linked telopeptide values (17.11±10.20 vs. 12.90±4.05; p=.067) compared with the patients with recurrent fractures.Conclusions: Bone metabolism and 25(OH)D levels seem to play a role in the occurrence of postkyphoplasty recurrent vertebral compression fractures.

A review of methods for evaluating the quantitative parameters of sagittal pelvic alignment - Corrected Proof

2012-04-06

Abstract: Background context: The sagittal alignment of the pelvis represents the basic mechanism for maintaining postural equilibrium, and a number of methods were developed to assess normal and pathologic pelvic alignments from two-dimensional sagittal radiographs in terms of positional and anatomic parameters.Purpose: To provide a complete overview of the existing methods for quantitative evaluation of sagittal pelvic alignment and summarize the relevant publications.Study design: Review article.Methods: An Internet search for terms related to sagittal pelvic alignment was performed to obtain relevant publications, which were further supplemented by selected publications found in their lists of references. By summarizing the obtained publications, the positional and anatomic parameters of sagittal pelvic alignment were described, and their values and relationships to other parameters and features were reported.Results: Positional pelvic parameters relate to the position and orientation of the observed subject and are represented by the sacral slope, pelvic tilt, pelvic overhang, sacral inclination, sacrofemoral angle, sacrofemoral distance, pelvic femoral angle, pelvic angle, and sacropelvic translation. Anatomic pelvic parameters relate to the anatomy of the observed subject and are represented by the pelvisacral angle (PSA), pelvic incidence (PI), pelvic thickness (PTH), sacropelvic angle (PRS1), pelvic radius (PR), femorosacral posterior angle (FSPA), sacral table angle (STA), and sacral anatomic orientation (SAO). The review was mainly focused on the evaluation of anatomic pelvic parameters, as they can be compared among subjects and therefore among different studies. However, ambiguous results were yielded for normal and pathologic subjects, as the reported values show a relatively high variability in terms of standard deviation for every anatomic parameter, which amounts to around 10 mm for PTH and PR; 10° for PSA, PI, and SAO; 9° for PRS1 and FSPA; and 5° for STA in the case of normal subjects and is usually even higher in the case of pathologic subjects. Among anatomic pelvic parameters, PI was the most studied and therefore represents a key parameter in the complex framework of sagittal spinal alignment and related deformities. From the reviewed studies, the regression lines for PI and the corresponding age of the subjects indicate that PI tends to increase with age for normal (PI=+0.17×age+46.40) and scoliotic (PI=+0.20×age+50.52) subjects and decrease with age for subjects with spondylolisis or spondylolisthesis (PI=−0.26×age+75.69).Conclusions: Normative values for anatomic parameters of sagittal pelvic alignment do not exist because the variability of the measured values is relatively high even for normal subjects but can be predictive for spinal alignment and specific spinopelvic pathologies.

Fear of movement/(re)injury and activity avoidance in persons with neurogenic versus vascular claudication - Corrected Proof

Derek W. Wood, Andrew J. Haig, Karen S.J. Yamakawa — 2012-04-06

Abstract: Background context: Activity avoidance and fear of movement/(re)injury are increasingly being recognized as important factors in the rehabilitation of persons suffering from chronic low back pain, yet these factors have not been thoroughly explored in persons suffering from neurogenic claudication resulting from lumbar spinal stenosis.Purpose: To determine, compare, and explain differences in the degree of fear of movement/(re)injury and activity avoidance in persons with neurogenic claudication, vascular claudication, and asymptomatic volunteers.Study design: Prospective controlled cohort study at an academic medical center.Patient sample: Eighty-two adults aged between 55 and 90 years with neurogenic claudication, vascular claudication, or no back and leg symptoms.Methods: Subjects completed a visual analog scale for pain, the Center for Epidemiological Studies Depression Scale, the Quebec Back Pain Disability Scale, Short Form 36 (SF-36), and the 13-item version of the Tampa Scale for Kinesiophobia (Tampa). They were also asked to estimate their maximum walking distance.Outcome measures: The difference in the level of fear of movement/(re)injury and activity avoidance in the two symptomatic populations, as well as the predictive validity of self-reported measures such as pain level, functional impairment, and depression in determining fear avoidance.Results: The total Tampa score was significantly higher in individuals with neurogenic claudication (M=31.68; standard deviation [SD]=7.56; N=39) than vascular claudication (M=24.07; SD=6.57; N=15) (p=.002), whereas both symptomatic groups were significantly different from controls (M=18.71; SD=6.3; N=28) (p<.001 vs. neurogenic; p<.05 vs. vascular). Tampa scores were strongly correlated to the Center for Epidemiological Studies Depression Scale score (r=0.515; p<.001), SF-36 Physical Functioning score (r=−0.632; p<.001), and the visual analog scale average level of pain in a week (r=0.461; p<.001). Using a standard multiple regression model (R²=0.406; F(3,62)=13.47; p<.001), the amount of functional impairment, that is, the SF-36 Physical Functioning score, was the strongest contributor to the variance in the Tampa total score (β=−0.371; p=.014). The average level of pain did not make a significant or unique contribution in predicting the Tampa total score. Functional impairment as measured by the SF-36 Physical Functioning was strongly correlated with both pain (r=−0.740; p<.001) and depression (r=−0.488; p<.001).Conclusions: Persons with neurogenic claudication have important elevations in fear and avoidance, higher than those with claudication from another source (vascular insufficiency). The impact of fear and avoidance along with other factors such as depression on pain, disability, and quality of life for persons with claudication and spinal stenosis need to be explored.

The biomechanical effect of pedicle screw hubbing on pullout resistance in the thoracic spine - Corrected Proof

2012-04-06

Abstract: Background context: The biomechanical fixation strength afforded by pedicle screws has been strongly correlated with bone mineral density. It has been postulated that “hubbing” the head of the pedicle screw against the dorsal laminar cortex provides a load-sharing effect, thereby limiting cephalocaudad toggling and improving the pullout resistance of the pedicle screw.Purpose: To evaluate the pullout strength (POS) of monoaxial hubbed pedicle screws versus standard fixation in the thoracic spine.Study design: Biomechanical investigation.Methods: Twenty-two human cadaveric thoracic vertebrae were acquired and dual-energy X-ray absorptiometry scanned. Osteoporotic (n=16) and normal (n=6) specimens were instrumented with a 5.0×35-mm pedicle screw on one side in a standard fashion. In the contralateral pedicle, 5.0×30-mm screw was inserted with hubbing of the screw into the dorsal lamina. A difference in screw length was used to achieve equivalent depth of insertion. After 2,000 cycles of cephalocaudad toggling, screws were pulled out with the tensile force oriented to the midline of the spine and peak POS measured in newtons (N). Four additional specimens were subjected to microcomputed tomography (micro-CT) analysis to evaluate internal pedicle architecture after screw insertion.Results: Hubbed screws resulted in significantly lower POS (290.5±142.4 N) compared with standard pedicle screws (511.5±242.8 N; p=.00). This finding was evident in both normal and osteoporotic vertebrae based on independent subgroup post hoc analyses (p<.05). As a result of hubbing, half of the specimens fractured through the lamina or superior articular facet (SAF). No fractures occurred on the control side. There was no difference in mean POS for hubbed screws with and without fracture; however, further micro-CT analysis revealed the presence of internal fracture propagation for those specimens that did not have any external signs of failure.Conclusions: Hubbing pedicle screws results in significantly decreased POS compared with conventional pedicle screws. Hubbing predisposes toward iatrogenic fracture of the dorsal lamina, transverse process, or SAF during insertion.

Case report: incisional hernia as a complication of extreme lateral interbody fusion - Corrected Proof

2012-04-05

Abstract: Background context: Minimal access surgery is becoming more popular for spinal fusion because of a lower theoretical risk of complications and shorter postoperative recovery period, compared with the traditional open approach. The lateral approach uses retroperitoneal transpsoas access to the vertebra, obviating the need for an approach surgeon and minimizing muscular disruption, thus allowing a quicker recovery. Initial reports of the lateral transpsoas procedure described few complications. However, a number of complications have subsequently been documented. To our knowledge, there has not been a description of an incisional hernia after this approach.Purpose: To report the rare complication of an incisional hernia after a minimal access lateral transpsoas approach for lumbar interbody fusion.Study design: Case report.Methods: We reviewed the hospital charts, radiographs, and intraoperative photographs of a patient who underwent a minimally invasive lateral approach lumbar spine fusion with a subsequent incisional hernia that necessitated laparoscopic repair.Results: A 75-year-old woman with a history of low back and left lower extremity pain with radiographic evidence of foraminal stenosis and degenerative spondylolisthesis underwent a successful L4–L5 discectomy with an extreme lateral interbody fusion via a retroperitoneal transpsoas approach. This was supplemented with a posterior minimally invasive surgery instrumented fusion from L4 to L5. The patient reported significant improvement in symptoms on initial follow-up, however, complained of a prominence over her incision 4 weeks later. An incisional hernia was diagnosed and subsequently repaired laparoscopically, from which the patient recovered uneventfully.Conclusions: Postoperative incisional hernia after extreme lateral interbody fusion is a complication that has not been previously described in the literature but is one that spine surgeons must recognize. This case may prompt surgeons to use a more posterior approach to avoid this complication. Additionally, direct repair of the transversalis fascia is critical to avoiding this complication.

Corrected Proof

Dan M. Spengler — 2012-03-30

I was pleased to have had the opportunity to provide a commentary in the June 2011 issue of The Spine Journal on the article in the same issue authored by Carragee et al. entitled “A critical review of recombinant human bone morphogenetic protein-2 trials in spinal surgery: emerging safety concerns and lessons learned.”

Mirza responds - Corrected Proof

Sohail K. Mirza — 2012-03-30

Thank you for asking me to describe my role in the publication of the article titled “A critical review of recombinant human morphogenetic protein-2 trials in spine surgery: emerging safety concerns and lessons learned” in The Spine Journal .

Corrected Proof

Eugene J. Carragee — 2012-03-30

I wish to thank Dr Anderson for his timely inquiry and believe that the following facts show that our manuscript, “A critical review of recombinant human morphogenetic protein-2 trials in spine surgery: emerging safety concerns and lessons learned,” was exhaustively reviewed and appropriately edited before publication.

Letter to the editor regarding “A critical review of recombinant human morphogenetic protein-2 trials in spine surgery: emerging safety concerns and lessons learned” - Corrected Proof

Paul A. Anderson — 2012-03-30

The article, “A critical review of recombinant human morphogenetic protein-2 trials in spine surgery: emerging safety concerns and lessons learned,” by Carragee et al. has created significant controversy. One concern by some readers is the editorial process of this manuscript. The difference between a standard newspaper or magazine and a scientific journal is critical peer review. This process needs to be blinded, fair, and critical. This is especially true when the author is the journal editor who could have an influence over the peer-review process. Given the attention this article has received, it is important that the readership of The Spine Journal understand how bias was avoided. Specifically, what was the peer-review process? Furthermore, what role did the North American Spine Society have in oversight of the special issue about bone morphogenetic protein 2 (BMP-2)? Conflicts of interest were noted to be a potential source of bias in “The critical review …” that may have skewed the authors' reporting of BMP-2 adverse events. Dr Carragee noted that he is a consultant to the Department of Justice, involved in litigation with Medtronic and perhaps many surgeons. Specifically, was this consultation in any way related to the BMP-2 critical review? Transparency of the review process as well as the conflicts of interest of authors is important for readers so that a proper evaluation of the potential bias can be performed.

Sparing the posterior surgical site when planning radiation therapy for thoracic metastatic spinal disease - Corrected Proof

2012-03-21

Abstract: Background context: Most patients with painful spinal metastases are sufficiently palliated by hypofractionated radiotherapy. However, a small group of patients will need surgical intervention to treat symptomatic spinal cord compression and/or gross mechanical instability. Irradiation of a (prospective) surgical area may lead to postsurgery complications, including wound dehiscence, infection, and chronic wound ulcers. Decreasing the radiation dose to the surgical area could reduce radiation-induced toxicity and associated surgical complications.Purpose: To investigate an alternative radiation technique designed to lower the surgical area dose while delivering an adequate target dose and minimal off-target dose.Study design: Comparison of radiation doses received by various anatomic structures after simulating irradiation with a routine posteroanterior single field (SF) technique and experimental multiple field (MF) technique in a setting of thoracic metastatic spinal disease.Methods: The computed tomography (CT) data from six previously treated patients with a total of 10 thoracic spinal metastases were used to plan four radiation schemes (SF8 Gy; SF20 Gy; MF8 Gy; and MF20 Gy). Discrete anatomic structures were defined on CT data, including a posterior surgical area, and after simulation the doses received were calculated and compared for the 8 Gy and 20 Gy techniques.Results: With the experimental MF technique, a clinically relevant dose could be delivered to the affected vertebra, whereas the dose received at the (prospective) surgical area could be significantly reduced compared with the SF technique. The dose received at the nontarget tissues fell below the threshold level for clinical relevance.Conclusions: This radiation planning study showed the feasibility of sparing the surgical area while delivering an adequate dose to affected vertebrae in thoracic metastatic spinal disease.

Deleterious effects of discography radiocontrast solution on human annulus cell in vitro: changes in cell viability, proliferation, and apoptosis in exposed cells - Corrected Proof

2012-03-19

Abstract: Background context: Carragee et al. have recently shown that modern discography injections are associated with subsequent acceleration of disc degeneration, herniation, and loss of disc height. Although needle puncture and pressurization are known trauma events that can create disc degeneration in animal models, another likely culprit in clinical discography–associated degeneration is a direct effect of the contrast agent itself on disc cells.Purpose: To test the hypothesis that discography contrast solution would have a deleterious effect on human annulus cells in vitro.Study design: An in vitro study using cultured human annulus cells to assay cell death, cell proliferation, and apoptosis.Patient sample: Annulus cells from eight surgical disc specimens were evaluated (two Thompson Grade III discs and six Grade IV discs) for cell death and proliferation, and an additional five cultures were tested for apoptosis.Outcome measures: The proportion of dead and live cells, cell proliferation, and the proportion of apoptotic cells in control and experimental groups.Methods: After internal review board approval, experimental design used two sets of controls: untreated cells under our normal culture conditions (control) and a set with added glucose to adjust the osmolality to match respective Isovue radiocontrast solution treatments (glucose controls) using a freezing point osmometer. Treated cells received Isovue 200 (iopamidol, Isovue-M 200; Bracco Diagnostics, Inc., Princeton, NJ, USA) at 12.5, 25, 50, or 100 mg/mL. Twenty thousand cells/well were seeded in triplicate in 24 well plates, control or test media added, and incubated for 24 hours. At termination, dead cells were identified with trypan blue staining and percentage dead cells determined. Cells were also tested to determine the percentage of apoptotic cells after 50 or 100 mg/mL Isovue exposures. Proliferation assays used standard plate reader methods. Statistical analysis used repeated measures analysis of variance with SAS software (version 9.2; SAS Institute, Inc., Cary, NC, USA).Results: Analysis of cell death showed a significant increase in the percentage of dead cells with increasing Isovue concentrations compared with control cells (p=.018–.0008). Cell proliferation analyses showed significantly reduced division in Isovue-treated cells (p=.004), and apoptosis assays revealed a significantly higher proportion of apoptotic cells in cells exposed to 50 and 100 mg/mL Isovue (p=.016 and .0003, respectively).Conclusions: Discography is used extensively in the evaluation of low back pain. Because the lifetime prevalence of disc degeneration and low back pain is high (80% in the general population), many patients may undergo this procedure. Data presented here show that cells exposed in vitro to a radiocontrast agent with adjustments for osmolality have significantly reduced proliferation, increased cell death, and increased programmed cell death (apoptosis). In light of the well-recognized age- and degeneration-related decrease in disc cell numbers, it is possible that radiocontrast exposure may be contributing significantly to disc cell loss with subsequent progression of disc degeneration. Findings presented here provide a plausible cell-based explanation for the previously reported disc degeneration in patients receiving discography contrast solutions.

Factors affecting reoperations after anterior cervical discectomy and fusion within and outside of a Federal Drug Administration investigational device exemption cervical disc replacement trial - Corrected Proof

2012-03-19

Abstract: Background context: The excellent clinical results of five US Federal Drug Administration (FDA) trials approved for cervical total disc replacement (TDR) (Prestige [Medtronic Sofamor Danek, Memphis, TN, USA], Bryan [Medtronic Sofamor Danek], ProDisc-C [Synthes, West Chester, PA, USA], Kineflex|C [SpinalMotion, Mountain View, CA, USA], and Mobi-C [LDR Spine, Austin, TX, USA]) have recently been published. In these prospective randomized studies, superiority or equivalency of TDR was claimed, citing an 8.7% (23/265), 9.5% (21/221), 8.5% (9/106), 12.2% (14/115), and 6.2% (5/81) (mean=9.02%) rate of additional related cervical surgical procedures within 2 years in control anterior cervical discectomy and fusion (ACDF) patients, respectively, compared with 1.8% (5/276), 5.8% (14/242), 1.9% (2/103), 11% (15/136), and 1.2% (2/164) (mean=4.34%) in patients receiving the cervical TDR. The rate of reoperation within 2 years after ACDF seems unusually high.Purpose: To assess the rate of and specific indications for early reoperation after ACDF in a cohort of patients receiving the ACDF as part of their customary care. These results are contrasted with similar patients receiving ACDF as the control arm of five FDA investigational device exemption (IDE) studies.Study design: Multisurgeon retrospective clinical series from a single institution.Patient sample: One hundred seventy-six patients with spondylotic radiculopathy or myelopathy underwent ACDF by three surgeons between 2001 and 2005 as part of their clinical practices. All patients had at least 2 years of follow-up with final follow-up within 6 months of completion of this study.Outcome measures: Cervical reoperation rates at 2-year follow-up and at 3.5-year follow-up.Methods: Review of medical records and telephone conversations were completed to determine the number of patients who had undergone a revision cervical procedure.Results: At final follow-up, complete data were available for 159 ACDF patients. Of the 48 patients who underwent single-level ACDF and met criteria for inclusion in the IDE studies, one patient (2.1%) required additional surgery (adjacent-segment degeneration) within 2 years, the duration of follow-up of the five published IDE studies. Of the 159 patients who received single or multilevel ACDF at a mean follow-up of 3.5 years, 12 patients (7.6%) had undergone revision cervical surgery, with three patients (1.9%) undergoing same-level revisions (posterior fusion) and nine patients (5.7%) undergoing adjacent anterior level fusions. Patients who underwent revision same-level surgery typically had the intervention within the first year (mean, 11 months), whereas those requiring adjacent-level fusions typically had surgery later (mean, 29 months).Conclusions: The present study identifies a 2.1% rate of repeat surgery within 2 years of a single-level ACDF performed during routine clinical practice, which is lower than that reported in the control arm of the Prestige, ProDisc-C, Bryan, Kineflex|C, and Mobi-C FDA trials (mean=9%). Even with longer follow-up including multilevel cases, our reoperation rate (7.6%) compared favorably with the IDE rates. This discrepancy may reflect different thresholds for reoperation in the control arm of a device IDE study compared with routine clinical practice. Additionally, patients enrolled in the single-level-only IDE trial may have received multilevel procedures outside of the study. This factor could result in a higher rate of subsequent surgeries at adjacent levels not addressed at the index procedure. These data suggest that we need to better understand factors driving treatment and, in particular, decisions to reoperate both in and outside of a device trial.

Effect of methodological quality measures in spinal surgery research: a metaepidemiological study - Corrected Proof

Wilco C.H. Jacobs, Moyo C. Kruyt, Ab J. Verbout, F. Cumhur Oner — 2012-03-02

Abstract: Background context: Methodological quality measures of trials in meta-analyses have been shown to influence the pooled effect sizes in several medical fields. However, for spinal surgery, influence of quality measures has not been assessed.Purpose: The purpose of this study was to analyze the influence of quality measures in studies on effectiveness in spinal surgery.Study design: A metaepidemiological study was performed on meta-analyses within spinal surgery.Methods: A systematic search was performed in MEDLINE, Cochrane Database, and EMBASE in August 2009. The effect sizes, defined as risk of positive clinical outcome, of trials included in the meta-analyses were assessed. The differences in effect sizes were calculated as risk differences (RDs). Relation of the RDs to potential quality measures such as sponsoring, randomization, allocation concealment, blinding, and study size was assessed with metaregression adjusted for multiple testing.Results: Seven reviews consisting of 118 studies were included. Data provided by the systematic reviews alone were insufficient to analyze the effect of quality measures. Metaregression analysis of 76 of the individual trials reporting clinical outcome, though, showed that sample size, strict randomization, and outcome blinding were significant quality measures influencing study effect. Risk difference of effect from validly randomized studies was higher compared with not validly randomized and comparative observational trials (5.4%; 95% confidence interval [CI], 1.2–9.6; p=.044). Studies with adequate observer blinding showed a 7.2% lower RD (95% CI, 0.8–13.7; p=.049). For each increase of 100 patients, the RD decreased 3.6% (95% CI, 0.5–6.8; p=.098).Conclusions: Contrary to basic methodological assertions, formal and strict randomization appeared to produce a significantly higher RD in spinal surgery research. Sufficient sample size and observer blinding, on the other hand, led to a lower RD as expected. These findings imply that effect of quality measures assessed in metaepidemiological studies should not be too easily translated to research in spinal surgery.

Predictors of low back pain in physically active conscripts with special emphasis on muscular fitness - Corrected Proof

2012-02-02

Abstract: Background context: Association between low physical fitness and low back pain (LBP) is contradictory in previous studies.Purpose: The objective of the present prospective cohort study was to investigate the predictive associations of various intrinsic risk factors in young conscripts for LBP, with special attention to physical fitness.Study design: A prospective cohort study.Patient sample: A representative sample of Finnish male conscripts. In Finland, military service is compulsory for male citizens and 90% of young men enter into the service.Outcome measures: Incidence of LBP and recurrent LBP prompting a visit at the garrison health clinic during 6-month military training.Methods: Four successive cohorts of 18- to 28-year-old male conscripts (N=982) were followed for 6 months. Conscripts with incidence of LBP were identified and treated at the garrison clinic. Predictive associations between intrinsic risk factors and LBP were examined using multivariate Cox proportional hazard models.Results: The cumulative incidence of LBP was 16%, the incidence rate being 1.2 (95% confidence interval [CI], 1.0–1.4) per 1,000 person-days. Conscripts with low educational level had increased risk for incidence of LBP (hazard ratio [HR], 1.6; 95% CI, 1.1–2.3). Conscripts with low dynamic trunk muscle endurance and low aerobic endurance simultaneously (ie, having coimpairment) at baseline also had an increased risk for incidence of LBP. The strongest risk factor was coimpairment of trunk muscular endurance in tests of back lift and push-up (HR, 2.8; 95% CI, 1.4–5.9).Conclusions: The increased risk for LBP was observed among young men who had a low educational level and poor fitness level in both muscular and aerobic performance.

Impact of coexistent lumbar spine disorders on clinical outcomes and physician charges associated with total hip arthroplasty - Corrected Proof

2012-01-09

Abstract: Background context: Despite the common prevalence of lumbar spine and degenerative hip disorders, there are few descriptions of patients with coexisting hip disorders and lumbar spine disorders (LSDs). The independent economic burden of each disorder is substantial, but the financial burden when the disorders are coexisting is unknown.Purpose: To determine the prevalence of coexisting hip disorders and LSDs in a large cohort of patients with hip osteoarthritis (OA) treated with total hip arthroplasty (THA) as well as the impact on pain and functional THA outcomes and physician charges.Study design: This is a retrospective study performed at a tertiary university.Patient sample: Three thousand two hundred six patients underwent total hip replacement from 1996 to 2008.Outcome measures: Self-report measures: visual analog scale. Functional measures: modified Harris Hip Score (mHHS) and University of California Los Angeles (UCLA) hip questionnaire. Economic impact measures: physician medical charges.Methods: International Classification of Diseases, Version 9, billing codes related to LSDs were cross-referenced with the 3,206 patients who had undergone a THA to determine which patients were also evaluated by a spine specialist. Demographic, hip clinical outcomes, and physician charges for patients with THA alone (THA alone) were compared with patients treated with THA and diagnosed with an LSD (THA+LSD).Results: Of 3,206 patients who underwent THA, 566 (18%) were also evaluated by a spine specialist. Of those with an LSD, 334 (59%) were women with an older average age (64.5±13.3 years) compared with patients treated with THA alone (51%, 58.5±15.5 years, p=.0001). Patients in the THA alone group as compared with the THA+LSD group had greater improvement in the mHHS (p=.0001), UCLA score (p=.0001), and pain (p=.0001). Patients in the THA+LSD group incurred on average $2,668 more in charges per episode of care as compared with patients in the THA alone group (p<.001). Patients in the THA+LSD group had more days per episode of care (p=.001).Conclusions: Patients undergoing THA alone had greater improvement in function and pain relief with fewer medical charges as compared with patients undergoing a THA and treatment for an LSD. The prevalence of coexisting hip disorders and spine disorders is likely higher than currently documented. Further study is needed to improve therapeutic recommendations and determine the potential for reduction in medical expenses associated with concurrent treatment of hip OA and LSDs.

Predictors of short-term work-related disability among active duty US Navy personnel: a cohort study in patients with acute and subacute low back pain - Corrected Proof

2012-01-09

Abstract: Background context: Musculoskeletal disorders of the spine in the US military account for the single largest proportion of the absence of sickness causes leading to early termination. We explored if selected psychological and physical factors were associated with poor outcome after episodes of low back pain (LBP).Purpose: To identify clinical, demographic, and psychological factors predictive of work duty status after a complaint of LBP.Study design: A prospective clinical cohort of US Navy personnel treated for LBP.Patient sample: Eligible cases were active duty US Navy or Marine Corps personnel presenting to an emergency clinic or primary care clinic with a complaint of LBP, where the index episode of LBP was no more than 12 weeks duration before enrollment.Outcome measures: The subject’s work status (full duty, light duty, sick in quarters [SIQ], limited duty, or medically released to full duty) was abstracted from the subject’s electronic medical record at approximately 4 weeks and then again 12 weeks after study enrollment. Work status in this study population is assigned by a Navy health-care provider at the time of a clinical visit and based on the health-care provider’s determination of medical fitness for duty. This study collapsed work status into two groups, “full duty” (consisting of “full duty” and “medically released to full duty”) and “not at full duty” (consisting of “light duty,” “SIQ,” and “limited duty”).Methods: Volunteers completed a baseline questionnaire consisting of recommended well-validated measures, including attitudes and beliefs about LBP and work (Fear-Avoidance Beliefs Questionnaire [FABQ] and the Tampa Scale of Kinesiophobia), distress (the Pain Catastrophizing Scale), clinical depression (The Center for Epidemiologic Studies Depression scale), a numeric pain intensity scale, self-perceived disability (Oswestry Disability Index), and general health status (12-Item Short Form Health Survey). Navy health-care providers conducted a back pain–specific medical evaluation. Associations are expressed as multivariate-adjusted prevalence ratios (PRs) estimated using Poisson regression.Results: Two hundred fifty-three participants were enrolled. Work status outcome was collected for 239 participants. Predictors of “not at full duty” at 4 weeks after enrollment included having back pain for 4 weeks or less before study enrollment (PR, 2.69; 95% CI, 1.21–5.97) and increased FABQ Work subscale score (PR, 1.05; 95% CI, 1.01–1.08). The sole predictor of work status at 12 weeks after enrollment was increased FABQ Physical Activity (FABQ Physical) subscale score (PR=1.14; 95% CI, 1.00–1.30).Conclusions: The findings that fear-avoidance beliefs were predictive of subsequent work status among active duty service personnel in this study population (after adjusting for clinical, demographic, and psychological covariates) suggest the clinical utility of addressing these factors during treatment of back pain episodes in the military. These findings reflect the important role that psychological factors may play in the return to work process in an active duty military population.

Wartime spine injuries: understanding the improvised explosive device and biophysics of blast trauma - Corrected Proof

Daniel G. Kang, Ronald A. Lehman, Eugene J. Carragee — 2011-12-26

Abstract: The improvised explosive device (IED) has been the most significant threat by terrorists worldwide. Blast trauma has produced a wide pattern of combat spinal column injuries not commonly experienced in the civilian community. Unfortunately, explosion-related injuries have also become a widespread reality of civilian life throughout the world, and civilian medical providers who are involved in emergency trauma care must be prepared to manage casualties from terrorist attacks using high-energy explosive devices. Treatment decisions for complex spine injuries after blast trauma require special planning, taking into consideration many different factors and the complicated multiple organ system injuries not normally experienced at most civilian trauma centers. Therefore, an understanding about the effects of blast trauma by spine surgeons in the community has become imperative, as the battlefield has been brought closer to home in many countries through domestic terrorism and mass casualty situations, with the lines blurred between military and civilian trauma. We set out to provide the spine surgeon with a brief overview on the use of IEDs for terrorism and the current conflicts in Iraq and Afghanistan and also a perspective on the biophysics of blast trauma.

Dynamic changes of elasticity, cross-sectional area, and fat infiltration of multifidus at different postures in men with chronic low back pain - Corrected Proof

2011-12-26

Abstract: Background Context: Multifidus cross-sectional area was often measured in chronic low back pain (LBP) patients to estimate the muscle activity for spinal stability. However, such estimation may be inadequate as the contribution of muscle elasticity in muscle activity is ignored. In vivo quantitative data on multifidus elasticity is therefore important for the study of muscle contractile function in response to motor control for spinal stability in chronic LBP patients.Purpose: The purpose of this study was to quantify the elasticity, cross-sectional area, and fat area of the multifidus for the contractile function and the distribution of deformable muscle tissue and nondeformable fat tissue at different postures in patients with and without chronic LBP.Study Design/Setting: This is a prospective study. Force-deformation data of the multifidus were acquired using ultrasound elastography. The anatomical changes of the multifidus were measured on the cross-sectional images of the multifidus acquired using B-mode ultrasound imaging.Patient Sample: The sample comprised 12 adult male patients with chronic LBP and 12 asymptomatic male controls.Outcome Measures: The outcome measure was the elasticity of the multifidus at the L4 level for the assessment of muscle contractile function when patients were in the prone, upright, and 25° and 45° forward stooping positions. The cross-sectional area and fat area were also measured on the B-mode ultrasound images of the multifidus acquired at the same vertebral level and the postures.Methods: With the patients in each of the prone, upright, and 25° and 45° forward stooping positions, ultrasound elastography and B-mode ultrasound imaging were performed on the left and right multifidus at the L4 level. The elasticity of multifidus indicated by the effective Young’s modulus was derived from the force-deformation data acquired using ultrasound elastography. The cross-sectional area and fat area were assessed on the B-mode ultrasound images. The effective Young’s modulus, cross-sectional area, and fat area were analyzed with multivariate general linear model analysis to investigate the possible effects of LBP and posture.Results: There was an increasing stiffness of multifidus demonstrated by increasing effective Young’s modulus from the prone to upright position and 25° and 45° forward stooping positions. Differences in multifidus stiffness between chronic LBP patients and asymptomatic controls were shown in the upright and 25° and 45° forward stooping positions but not in the prone position. The cross-sectional area of the multifidus increased from the prone position to the greatest value in the upright position and decreased in 25° and 45° forward stooping positions. Smaller multifidus cross-sectional area was demonstrated in chronic LBP patients than that in controls at all postures. No effect of posture on fat area within the multifidus was shown although the fat area within the multifidus was larger in chronic LBP patients.Conclusions: Different, changing patterns of elasticity and cross-sectional area were identified in the multifidus in relation to posture. Increased stiffness of multifidus in response to the physiologic range of static loads and smaller cross-sectional area was characterized in the chronic LBP condition for spinal stability. Ultrasound elastography offers in vivo assessment of muscle contractile function of deep trunk muscles, which benefits the future investigation of the neuromuscular regulating mechanism in LBP. It can also be applied to refine the palpatory skill for the physical assessment in sports training and physical therapy.

The effect of vehicle protection on spine injuries in military conflict - Corrected Proof

2011-12-19

Abstract: Background context: To evaluate the effect of critical time periods in vehicle protection on spine injuries in the Global War on Terror.Purpose: To characterize the effect of method of movement on and around the battlefield during Operation Enduring Freedom and Operation Iraqi Freedom from 2001 to 2009 in terms of its impact on the incidence and severity of spinal fractures sustained in combat.Study design/setting: Retrospective study.Patient sample: Mounted and dismounted American servicemembers who were injured during combat.Methods: Extracted medical records of servicemembers identified in the Joint Theater Trauma Registry from October 2001 to December 2009. Methods of movement were defined as mounted or dismounted. Two time periods were compared. Cohorts were created for 2×2 analysis based on method of movement and the time period in which the injury occurred. Time period 1 and 2 were separated by April 1, 2007, which correlates with the initial fielding of the modern class of uparmored fighting vehicles with thickened underbelly armor and a V-shaped hull. Our four comparison groups were Dismounted in Time Period 1 (D1), Dismounted in Time Period 2 (D2), Mounted in Time Period 1 (M1), and Mounted in Time Period 2 (M2).Results: In total, 1,819 spine fractures occurred over the entire study period. Four hundred seventy-two fractures (26%) were sustained in 145 servicemembers who were mounted at the time of injury, and 1,347 (74%) were sustained by 404 servicemembers who were dismounted (p<.0005). The incidence of fractures in the dismounted cohort (D1+D2) was significantly higher than in the mounted cohort (M1+M2) in both time periods (D1 vs. M1, 13.75 vs. 3.95/10,000 warrior-years [p<.001] and D2 vs. M2, 11.15 vs. 4.89/10,000 warrior-years [p<.0001]). In both the mounted and dismounted groups, the thoracolumbar (TL) junction was the most common site of injury (36.1%). Fractures to the TL junction (T10–L3) increased significantly from Time Period 1 to 2 (34% vs. 40% of all fractures, respectively, p=.03). Thoracolumbar fractures were significantly more severe in that there were more Arbeitsgemeinschaft fur Osteosynthesefragen/Magerl Type A injuries versus all TL fractures, 1.75 versus 2.68/10,000 or 27% of all spine fractures in Time Period 1 versus 40% in Time Period 2 (p=.007). Furthermore, there were significantly fewer minor fractures (spinous process and transverse process fractures) (p<.0001). In Time Period 2, significantly more TL spine fractures were classified as major fractures, according to the Denis classification system, in both the mounted and dismounted groups; M1 group, 61 of 226 (27%) versus the M2 group, 86 of 246 (34%) (p<.0005) and 173 of 786 (22%) in the D1 group versus 193 of 561 (34%) in the D2 group. The spinal cord injury (SCI) incidence did not change in the mounted groups in Time Period 1 (7 of 71, 9.9%) versus Time Period 2 (7 of 74, 9.5%) (p=.935). In the dismounted groups, SCI actually decreased from D1 (55 of 228, 24%) to D2 (28 of 176, 16%) (p=.0428).Conclusions: The incidence of spine fractures and SCI is significantly higher in dismounted operations. The data suggest that current uparmored vehicles convey greater protection against spinal fracture compared with dismounted operations in which servicemembers are engaged on foot, outside their vehicles. The TL junction is at greatest risk for spine fractures sustained in mounted and dismounted combat operations. Recently, the incidence of TL fractures, especially severe fractures, has significantly increased in mounted operations. Although there has been an increased incidence of TL spine fractures, in context of the number of servicemembers deployed in support of Operation Enduring Freedom/Operation Iraqi Freedom, these severe fractures still represent a relatively rare event.

Open lumbosacral spine fractures with thecal sac ligation after combat blast trauma - Corrected Proof

Daniel G. Kang, John P. Cody, Ronald A. Lehman — 2011-12-02

A 22 year-old male soldier sustained combat blast trauma from an improvised explosive device, resulting in open L4 vertebral body and L5 burst fractures and an open comminuted lumbopelvic dissociation injury (), as well as multiple other injuries (open right comminuted iliac wing fracture, significant presacral/gluteal soft-tissue injuries, and bilateral traumatic above knee amputations). His open spine injuries required irrigation and debridement, followed by L2/L3 laminectomies and ligation of his violated thecal sac at L2. The thecal ligation resulted in bowel and bladder dysfunction requiring chronic colonic diversion, suprapubic catheter, and artificial uretheral sphincter implantation.

Complications associated with military spine injuries - Corrected Proof

2011-11-21

Abstract: Background context: To assess the presence of complications associated with spine injuries in the Global War on Terror.Purpose: To characterize the effect of complications in and around the battlefield during Operation Enduring Freedom and Operation Iraqi Freedom from 2001 to 2009.Study design/setting: Retrospective study.Patient sample: American servicemembers sustaining spine injury during combat.Methods: Extracted medical records of warriors identified by the Joint Theater Trauma Registry from October 2001 to December 2009. Complications were defined as unplanned medical events that required further intervention. Complications were classified as major or minor and further subdivided among groups, including surgical and nonsurgical management, mounted (in an armored vehicle) or dismounted at the time of injury, and blunt or penetrating trauma.Results: Major complications were encountered in 55 servicemembers (9%), and 38 (6%) sustained minor complications. Forty-four percent (n=24) of those with major complications had more than one complication. Eleven servicemembers sustained three or more complications. There were five intraoperative complications, and 50 occurred in the perioperative period. Intraoperative complications included gastrointestinal injury, dural tear, and instrument malposition. Among patients who sustained complications, precipitating spinal injuries occurred primarily in combat (n=43 [78%]) and resulted from blunt (18) or penetrating (25) mechanisms. Complications occurred in 10 (3%) of those treated nonoperatively and 45 (25%) of those receiving surgery. Complications were higher in the dismounted group (80%) as compared with those who were mounted in vehicles at the time of injury (20%). Thirty-five percent (n=24) of surgically treated, dismounted, and penetrating injured servicemembers had complications. Seventeen percent (n=8) of surgically treated and blunt injured mounted servicemembers and 20% (n=13) of dismounted servicemembers had complications. Among the dismounted and nonspinal cord–injured servicemembers, both blunt (p=.002) and penetrating injured (p<.0005) treated with surgery were correlated with complications. Only the dismounted servicemembers with spinal cord injuries because of a penetrating mechanism were also at an increased risk for complications (p<.0005).Conclusions: Patients treated with surgery appear to be at increased complication risk regardless of the mechanism of injury. Uparmored vehicles may safeguard servicemembers from spine injuries and complications associated with their treatment. This may be reflective of the fact that less severe spinal and concomitant injuries are sustained in the precipitating trauma because of the protection afforded by the vehicle. Dismounted soldiers had more complications in all groups regardless of type of management or injury mechanism.

Military penetrating spine injuries compared with blunt - Corrected Proof

2011-11-21

Abstract: Background context: The nature of blunt and penetrating injuries to the spine and spinal column in a military combat setting has been poorly documented in the literature. To date, no study has attempted to characterize and compare blunt and penetrating spine injuries sustained by American servicemembers.Purpose: The purpose of this study was to compare the military penetrating spine injuries with blunt spine injuries in the current military conflicts.Study design/setting: Retrospective study.Patient sample: All American military servicemembers who have been injured while deployed in Iraq (Operation Iraqi Freedom) and Afghanistan (Operation Enduring Freedom) whose medical data have been entered into the Joint Theater Trauma Registry (JTTR).Methods: The JTTR was queried for all American servicemembers sustaining an injury to the spinal column or spinal cord while deployed in Iraq or Afghanistan. These data were manually reviewed for relevant information regarding demographics, mechanism of injury, surgical intervention, and neurologic injury.Results: A total of 598 servicemembers sustained injuries to the spine or spinal cord. Isolated blunt injuries were recorded in 396 (66%) servicemembers and 165 (28%) sustained isolating penetrating injuries. Thirty servicemembers (5%) sustained combined blunt and penetrating injuries to the spine. The most commonly documented injuries were transverse process fractures, compression fractures, and burst fractures in the blunt-injured servicemembers versus transverse process fractures, lamina fractures, and spinous process fractures in those injured with a penetrating injury. One hundred four (17%) servicemembers sustained spinal cord injuries, comprising 10% of blunt injuries and 38% of penetrating injuries (p<.0001). Twenty-eight percent (28%) of blunt-injured servicemembers underwent a surgical procedure compared with 41% of those injured by penetrating mechanisms (p=.4). Sixty percent (n=12/20) of blunt-injured servicemembers experienced a neurologic improvement after surgical intervention at follow-up compared with 43% of servicemembers (n=10/23) who underwent a surgical intervention after a penetrating trauma (p=.28). Explosions accounted for 58% of blunt injuries and 47% of penetrating injuries, whereas motor vehicle collisions accounted for 40% of blunt injuries and 2% of penetrating injuries. Concomitant injuries to the abdomen, chest, and head were common in both groups.Conclusions: Blunt and penetrating injuries to the spinal column and spinal cord occur frequently in the current conflicts in Iraq and Afghanistan. Penetrating injuries result in significantly higher rates of spinal cord injury and trend toward increased rates of operative interventions and decreased neurologic improvement at follow-up.

Spine-area pain in military personnel: a review of epidemiology, etiology, diagnosis, and treatment - Corrected Proof

2011-11-21

Abstract: Background context: Nonbattle illnesses and injuries are the major causes of unit attrition in modern warfare. Spine-area pain is a common disabling injury in service members associated with a very low return-to-duty (RTD) rate.Purpose: To provide an overview of the current understanding of epidemiology, possible causes, and relative prognosis of spine-area pain syndromes in military personnel, including a discussion of various treatment options available in theaters of operation.Study design: Literature review.Methods: Search focusing on epidemiology, etiology and associative factors, and treatment of spinal pain using electronic databases, textbooks, bibliographic references, and personal accounts.Results: Spine-area pain is the most common injury or complaint “in garrison” and appears to increase during training and combat deployments. Approximately three-quarters involve low back pain, followed by cervical and midback pain syndromes. Some predictive factors associated with spine-area pain are similar to those observed in civilian cohorts, such as psychosocial distress, heavy physical activity, and more sedentary lifestyle. Risk factors specific to military personnel include concomitant psychological trauma, g-force exposure in pilots and airmen, extreme shock and vibration exposure, heavy combat load requirements, and falls incurred during airborne, air assault, and urban dismounted ground operations. Effective forward-deployed treatment has been difficult to implement, but newer strategies may improve RTD rates.Conclusions: Spine-area pain syndromes comprise a major source of unit attrition and are often the result of duty-related burdens incurred during combat operations. Current strategies in theaters of operation that may improve the low RTD rates include individual and unit level psychological support, early resumption of at least some forward-area duties, multimodal treatments, and ergonomic modifications.

Psychological distress in a Department of Veterans Affairs spine patient population - Corrected Proof

2011-11-17

Abstract: Background context: The veteran population presents a unique confluence of biopsychosocial factors in the treatment of spinal conditions. In addition to poorer health status and higher numbers of chronic medical conditions compared with the general population, previous reports have highlighted the high prevalence of psychological disorders within the Department of Veterans Affairs (VA) health system. To our knowledge, no study has specifically evaluated psychological distress in patients with a spinal disorder within the VA health system.Purpose: To determine the prevalence of psychological distress among spine patients in a VA hospital and if higher levels of distress correlated with patient demographics and self-reported patient outcome scores.Study design/setting: Cross-sectional evaluation of adult patients at a regional VA outpatient orthopedic spine surgery clinic.Patient sample: One hundred forty-nine adult patients presenting for treatment of spine-related disorders.Outcome measures: Patients were evaluated using the Distress and Risk Assessment Method (DRAM), a validated survey consisting of the Zung Depression Scale and the Modified Somatic Perception Questionnaire. In addition, self-reported pain, disability, and quality of life were assessed using the visual analog scale (VAS) for neck or back pain and the Neck Disability Index or Oswestry Disability Index (ODI) depending on the patient’s location of pain.Methods: The DRAM survey was used to determine the prevalence of psychological distress by classifying patients into normal, at-risk, and severe distress groups. Visual analog scale scores for neck and back pain, and self-reported disability scores, and demographic data including age, gender, combat experience, and use of antidepressant, anxiolytic, or narcotic medications were obtained at the time of enrollment.Results: The DRAM survey identified 79.9% of patients as having some degree of psychological distress, whereas the remaining 20.1% were classified as normal. Among those with psychological distress, 43.6% of patients were categorized as severe distress. Compared with the normal group, a history of combat was more frequent in all distressed patient groups including the at-risk (p=.04) and severe distress (p=.009) groups. Those in the severe distress category more commonly reported the use of narcotics (p=.043) and antidepressant/anxiolytics medications (p=.0001). Those in the severe distress group had significantly higher ODI scores (p<.0001) and back pain VAS scores (p=.0360) compared with the normal group.Conclusions: We identified a large number of patients (80%) with some level of psychological distress and 43% with severe distress. The percent of patients with severe psychological distress in the VA was double that previously reported in a non-VA patient setting. Patients with severe distress had higher ODI scores, back pain VAS scores, use of narcotics and antidepressants, and a reported history of combat when compared with those without distress.

Multiple associated injuries are common with spine fractures during war - Corrected Proof

2011-11-04

Abstract: Background context: The nature of concomitant injuries associated with spine fractures in American military personnel engaged in Operation Enduring Freedom (OEF) and Operation Iraqi Freedom (OIF) has been poorly documented in the literature.Purpose: To characterize the incidence and epidemiology of associated injuries (AIs) in American military personnel with spine fractures sustained during OEF and OIF from 2001 to 2009.Study design: Retrospective study.Patient sample: American military personnel who were injured in a combat zone and whose medical data were abstracted in the Joint Theater Trauma Registry (JTTR).Outcome measures: Not applicable.Methods: The JTTR was queried using International Statistical Classification of Disease, Ninth Revision codes to identify all individuals who sustained spine injuries in OEF or OIF from October 2001 to December 2009. Medical records of all identified service members were abstracted to ensure accuracy and avoid duplication. Demographic information, including sex, age, and military rank, were obtained for all patients. Information regarding fracture type, spine region, mechanism of injury, and the presence of AIs was collected for all patients.Results: Seventy-eight percent of patients with a spine fracture sustained at least one AI, with an average of 3.4 AIs per patient. Musculoskeletal injuries were most common, followed by chest, abdomen, and traumatic brain injuries. Most patients were injured by an explosive mechanism (62%). Head and face traumas were more common with cervical fractures, chest with thoracic injuries, and abdominopelvic injuries with lumbosacral fractures. Pelvis and acetabulum fractures were common after helicopter crashes, tibia/fibula injuries after explosions, thoracoabdominal injuries after gunshot wounds, and traumatic brain injuries after falls. Most patients (76%) sustained multiple spine fractures.Conclusion: Spine fractures sustained in OEF and OIF have high rates of AIs. Musculoskeletal AIs are the most common, but visceral injuries adjacent to the spine fracture frequently occur. Multiple spine injuries are more prevalent after military trauma.

Corrected Proof

Jean-Claude G. D’Alleyrand — 2011-10-24

The injuries sustained by America’s service members deployed in the current wars in Iraq and Afghanistan are of a much higher level of energy than those incurred in prior conflicts. Improvements in body and vehicular armor, as well as advances in combat resuscitative techniques and rapid evacuation to centers of surgical care, are allowing wounded individuals to survive injuries that previously would have been uniformly fatal. Moreover, these injuries are usually sustained as a result of a blast mechanism, which by their nature create injuries of the highest possible energy. As a result, the military orthopedic community has been treating an unprecedented number of extremely complex injuries. In “Combat Orthopedic Surgery: Lessons Learned in Iraq and Afghanistan,” editors Owens and Belmont attempt to catalog the general types of orthopedic injuries treated in the military during the first 10 years of these conflicts, along with the most recent evidence- and practice-based guidelines regarding the surgical care thereof. Their goal is to provide a comprehensive and definitive text to optimally guide the surgical treatment of these injuries both in-theater and at the final treatment facility.

Are spine injuries sustained in battle truly different? - Corrected Proof

2011-10-17

Abstract: Background context: The severity and prognosis of combat-related injuries to the spine and spine injuries sustained unrelated to direct combat have not been previously compared. Differences may have implications on tactics, treatment strategies, and directions for future research.Purpose: Compare the severity and prognosis of battle and nonbattle injuries to the spine.Study design: Retrospective study.Patient sample: American military personnel who were injured in a combat zone and whose medical data were abstracted in the Joint Theater Trauma Registry (JTTR).Methods: The JTTR was queried using International Statistical Classification of Diseases, Ninth Revision codes to identify all individuals who sustained battle and nonbattle injuries to the neck, back, spinal column, or spinal cord in Operation Iraqi Freedom or Operation Enduring Freedom from October 2001 to December 2009. Medical records of all identified servicemembers were individually reviewed. Demographic information, including sex, age, military rank, date of injury, and final disposition, was obtained for all patients. Spinal injuries were categorized according to anatomic location, associated neurologic involvement, precipitating mechanism of injury (MOI), and concomitant wounds. These data points were compared for the groups battle spine injuries (BSIs) and nonbattle spine injuries (NBSIs).Results: Five hundred two servicemembers sustained a total of 1,834 battle injuries to the spinal column, including 1,687 fractures (92%), compared with 92 servicemembers sustaining 267 nonbattle spinal column injuries, with 241 (90%) fractures. Ninety-one BSI servicemembers (18% of patients) sustained spinal cord injuries (SCIs) with 41 (45%) complete SCIs, compared with 13 (14% of patients) nonbattle SCIs with six (46.2%) complete injuries (p=.92). The reported MOI for 335 BSI servicemembers (66.7%) was an explosion compared with one NBSI explosive injury. Eighty-four patients (17%) sustained gunshot wounds (GSWs) in battle compared with five (5.2%) nonbattle GSWs. Fifteen patients (3.0%) sustained a battle-related fall compared with 29 (30%) nonbattle-related falls. Battle spine injury servicemembers underwent significantly higher rates of surgical interventions (p<.0001), were injured by high-energy injury mechanisms at a significantly greater rate (p<.0001), and demonstrated a trend toward lower neurologic recovery rates after SCI (p=.16).Conclusions: Battle spine injury and NBSI are separate entities that may ultimately have disparate long-term prognoses. Nonbattle spine injury patients, although having similar MOIs compared with civilian spinal trauma, maintain a different patient demographic. Further research must be directed at accurately quantifying the long-term disabilities of all spine injuries sustained in a combat theater, whether they are the result of battle or not.

Low lumbar burst fractures: a unique fracture mechanism sustained in our current overseas conflicts - Corrected Proof

2011-10-10

Abstract: Background context: The most common location for burst fractures occurs at the thoracolumbar junction, where the stiff thoracic spine meets the more flexible lumbar spine. With our current military conflicts in Iraq and Afghanistan, we have seen a disproportionate number of low lumbar burst fractures.Purpose: To report our institutional experience in the management of low lumbar burst fractures.Study design: Retrospective review.Methods: We performed a retrospective review of medical records and radiographs for all patients treated at our institution with combat-related injuries and thoracolumbar fractures. We included all patients who had sustained a burst fracture from T12 to L5 and had at least 1-year clinical follow-up.Results: Thirty-two patients sustained burst fractures. Nineteen patients (59.4%) had low lumbar (L3–L5) burst fractures, and 12 patients (37.5%) had thoracolumbar junction (T12–L2) burst fractures as their primary injury. Additionally, seven patients sustained less severe burst fractures at an additional level. One patient sustained burst fractures at both upper and lower lumbar levels. Of the low lumbar fractures, 52.6% had evidence of neurologic injury, two of which were complete. Similarly, in the upper lumbar group, 58.2% sustained a neurologic injury, two of which were complete. Twenty-two patients underwent surgical intervention, complicated by infection in 18%. At most recent follow-up, all but one patient with presenting neurologic injury had persistent deficits.Conclusion: Low lumbar burst fractures are the predominant combat-related spine injury in our current military conflicts. The rigidity offered by current body armor may effectively lower the transition zone that normally occurs at the thoracolumbar junction, thereby, transferring forces into the lower lumbar spine. Increased awareness of this fracture pattern is warranted by all surgeons because of unique clinical challenges associated with its treatment. Although the incidence is increased in the military population, other surgeons may be involved with long-term care of these patients on completion of their military service.

Combat-related L3 fracture treated with L2–L4 posterior spinal fusion complicated by multidrug-resistant acinetobacter infection - Corrected Proof

Theodora C. Dworak, Daniel G. Kang, Ronald A. Lehman — 2011-07-26

A 22-year-old active duty soldier injured by an improvised explosive device sustained an L3 compression fracture with right L3 pedicle and superior facet fractures and right L1, L2, and L3 transverse process fractures (). The patient also sustained a C7 spinous process fracture and left closed tibia fracture. On arrival to our institution, the patient had normal sensation and motor function in all extremities. At 11 days after injury, the patient underwent L2–L4 posterior spinal fusion (). On postoperative Day 6, he underwent an irrigation and debridement and antibiotic-impregnated cement bead placement for persistent serosanguinous drainage from his wound (). Intraoperative tissue cultures were positive for multidrug-resistant Acinetobacter spp. The patient continued to have episodic fevers and required two additional irrigation and debridement procedures with antibiotic bead placement before tissue cultures were negative. The wound was closed primarily with retained instrumentation 20 days after the index surgery. He was presumed to have osteomyelitis and was treated with 6 weeks of intravenous meropenem and oral rifampin. At 4-month follow-up, the patient denied constitutional signs of infection or significant back pain, and imaging showed stable L2–L4 instrumentation (). Infection of traumatic wounds with multidrug-resistant organisms has been an increasing problem in injured soldiers returning from Iraq and Afghanistan . Primary osteomyelitis in injured combat veterans is often polymicrobial, with gram-negative rods, such as Acinetobacter spp, Klebsiella pneumoniae, and Pseudomonas aeruginosa being the most common organisms. In the combat casualty with suspected infection after spinal surgery, spinal instrumentation is usually retained, particularly in the setting of an unstable spine fracture. Aggressive debridement, wound irrigation, and antibiotic bead placement are repeated until negative tissue cultures, and an extended course of intravenous antibiotics is warranted to decrease the risk of chronic osteomyelitis and pseudarthrosis .

Combat-related lumbopelvic dissociation treated with percutaneous sacroiliac screw placement - Corrected Proof

John P. Cody, Daniel G. Kang, Ronald A. Lehman — 2011-07-18

A 25-year-old male active duty soldier injured in an improvised explosive device blast sustained a stable U-type sacral fracture (S1/S2, bilateral Zone II) with 20° sacral kyphosis (). The patient also sustained left L5 transverse process and facet fracture with L5/S1 retrolisthesis. He had no neurologic deficits on arrival to our institution and was placed in a thoracolumbar support orthosis for his lumbar spine injury. On postinjury Day 12, the patient underwent bilateral SI screw placement. Six-months postoperative, the patient had resumed jogging activities without difficulty and did not exhibit lower extremity weakness, bowel/bladder dysfunction, or perineal numbness. Postoperative radiographs demonstrate adequate screw placement without evidence of progressive kyphosis, implant failure, or loosening (). The patient was released for activity as tolerated. At our institution, we have seen an increased incidence of lumbopelvic dissociation injury because of the high-energy blast mechanisms associated with combat in current conflicts. The patient in the above case did not require posterior decompression because of lack of neurologic compromise and was managed with bilateral sacroiliac screw placement, which has shown comparable results with regard to fracture healing and neurologic recovery .

Combat-related lumbopelvic dissociation treated with L4 to ilium posterior fusion - Corrected Proof

Daniel G. Kang, John P. Cody, Ronald A. Lehman — 2011-07-18

A 25-year-old active duty soldier injured in an improvised explosive device blast sustained a comminuted H-type sacral fracture (Zone III) with 100% displacement of S1 on S2 with 23° kyphosis, bilateral sacroiliac joint disruption, and right L2/L4/L5 transverse process fractures (). In the blast, the patient also sustained bilateral transtibial amputations, left acetabular fracture, liver laceration, multiple rib fractures, and left pneumothorax. On presentation, the patient had normal rectal tone and sensation, with sensation intact to light touch throughout both residual lower extremities. The patient required multiple procedures for his associated injuries, was stable for prone positioning at 4 weeks after injury, and subsequently underwent L4 to ilium posterior fusion (). At 2-year follow-up, a computed tomography scan demonstrated fracture consolidation without evidence of loosening or failure of implants (). However, he complained of skin irritation associated with a prominent left ilium screw, which was removed without significant sequelae (). He returned to ambulating with bilateral lower extremity prosthetics without difficulty.

Combat-related L5 burst fracture treated with L4–S1 posterior spinal fusion - Corrected Proof

Daniel G. Kang, Theodora C. Dworak, Ronald A. Lehman — 2011-07-18

A 27-year-old active duty soldier after blast injury from an improvised explosive device sustained an L5 burst fracture and L4 compression fracture, disruption of the posterior ligamentous complex, and posterior displacement of the L5 vertebral body with 50% narrowing of the spinal canal (). The patient's other injuries included bilateral transfemoral amputations and multiple facial fractures. On arrival to our institution, the patient's examination demonstrated normal rectal tone, with intact bilateral thigh and sacral nerve root sensation, and intact bilateral hip flexion and abduction limited by pain from his amputations. Three weeks after injury, the patient underwent an L4–S1 posterior spinal fusion with pedicle screw and rod instrumentation (). The patient started physical therapy on postoperative Day 2. At 7-month follow-up, the patient complained of persistent bilateral sharp radicular pain in his residual lower extremities. Imaging demonstrated no evidence of instrumentation failure or loosening, and no residual canal compromise (). The patient was treated with interlaminar corticosteroid injections, radio frequency nerve ablation therapy, and Botox injections. At 16-month follow-up, the patient was pain free, spending over 12 hours a day in his bilateral lower extremity prostheses, and able to independently walk over one-mile.

Bearing surfaces for total disc arthroplasty: metal-on-metal versus metal-on-polyethylene and other biomaterials - Corrected Proof

S. Raymond Golish, Paul A. Anderson — 2011-06-23

Abstract: Background context: Concerns about the effect of metallic wear debris from metal-on-metal bearing surfaces in total hip arthroplasty have increased. Some spinal arthroplasty devices include metal-on-metal bearing surfaces.Purpose: To review the literature for clinical reports of complications because of wear debris from metal-on-metal spinal arthroplasty devices. To review the biology of wear debris from metal-on-metal bearing surfaces drawn from the hip arthroplasty literature and place it in the context of global regulatory actions and clinical and laboratory studies.Study design: Literature review.Methods: To identify clinical reports, the PubMed database from the United States National Library of Medicine was queried using Medical Subject Headings terms and additional keyword terms. In addition, experts from academia and regulatory agencies were questioned regarding their knowledge of reports, including experts who attended the US Food and Drug Administration roundtable in September 2010.Results: Three case reports and one case series including seven total cases were identified in which abnormal inflammatory reactions and soft-tissue masses after metal-on-metal disc replacements were consistent with pseudotumor and metal hypersensitivity. Spinal cases are present as pain and neurologic symptoms. On plain radiography, there is no clear periprosthetic osteolysis or loosening. On magnetic resonance imaging, there is increased magnetic susceptibility artifact because of metallic debris that renders images inadequate. Computed tomography myelography demonstrates a soft-tissue mass, which exhibits epidural extension surgically. Histologically, large areas of necrotic debris and exudates are interspersed with chronic inflammatory cells. Lymphocyte or macrophage predominance is determined by the rate of wear and the presence of gross, microscopic, or submicron metallic wear debris. The metallurgy of the involved devices is cobalt-chromium-molybdenum (CoCrMo) alloy, and the bearing surface is CoCrMo-on-CoCrMo.Conclusions: Metal-on-metal spinal arthroplasty devices are subject to postoperative complications because of metallic wear debris with similar clinical, radiographic, histologic, gross anatomic, and device-related features to those found in metal-on-metal bearing surfaces in total hip arthroplasty.

Evaluation and management of combat-related spinal injuries: a review based on recent experiences - Corrected Proof

Andrew J. Schoenfeld, Ronald A. Lehman, Joseph R. Hsu — 2011-06-03

Abstract: Background context: The current approach to the evaluation and treatment of military casualties in the Global War on Terror is informed by medical experience from prior conflicts and combat encounters from the last 10 years. In an effort to standardize the care provided to military casualties in the ongoing conflicts, the Department of Defense (DoD) has published Clinical Practice Guidelines (CPGs) that deal specifically with the combat casualty sustaining a spinal injury. However, the combat experience with spine injuries in the present conflicts remains incompletely described.Purpose: To describe the CPGs for the care of the combat casualty with suspected spine injuries and discuss them in light of the published military experience with combat-related spinal trauma.Study design: Literature review.Methods: A literature review was conducted regarding published works that discussed the incidence, epidemiology, and management of combat-related spinal trauma. The CPGs, established by the DoD, are discussed in light of actual military experiences with spine trauma, the present situation in the forward surgical teams and combat support hospitals treating casualties in theater, and recent publications in the field of spine surgery.Results: In the conventional wars fought by the United States between 1950 and 1991 (Korea, Vietnam, Gulf War I), the incidence of spine injuries remained close to 1% of all combat casualties. However, in the Global War on Terror, the enemy has relied on implements of asymmetric warfare, including sniper attacks, ambush, roadside bombs, and improvised explosive devices. The increase in explosive mechanisms of injury has elevated the number of soldiers exposed to blunt force trauma and, consequently, recent publications reported the highest incidence of combat-related spinal injuries in American military history. Wounded soldiers are expeditiously evacuated through the echelons of care but typically do not receive surgical management in theater. The current CPGs for the care of soldiers with combat-related spinal injuries should be re-examined in light of data regarding the increasing number of spine injuries, new injury patterns, such as lumbosacral dissociation and low lumbar burst fractures, and recent reports within the field of spine surgery as a whole.Conclusions: American and coalition forces are sustaining the highest spine combat casualty rates in recorded history and previously unseen injuries are being encountered with increased frequency. While the CPGs provide useful direction in terms of the evaluation and management of combat casualties with spine injuries, such recommendations may warrant periodic re-evaluation in light of recent combat experiences and evolving scientific evidence within the spine literature.

Epidemiology of cervical spine fractures in the US military - Corrected Proof

2011-03-10

Abstract: Background context: The epidemiology of cervical spine fractures and associated spinal cord injury (SCI) has not previously been estimated within the American population.Purpose: To determine the incidence of cervical spine fractures and associated SCI and identify potential risk factors for these injuries in a large multicultural military population.Study design: Query of a prospectively collected military database.Patient sample: The 13,813,333 military servicemembers serving in the US Armed Forces between 2000 and 2009.Outcome measures: The Defense Medical Epidemiology Database (DMED) was queried to identify all servicemembers diagnosed with cervical spine fractures with and without SCI during the time period under investigation. Data were used to determine the incidence of cervical spine fractures and SCI as well as identify risk factors for their development.Methods: The DMED was queried for the years 2000 to 2009 using the International Classification of Diseases, Ninth Revision, Clinical Modification code for cervical spine fractures with and without SCI (805.0, 805.1, 806.0, and 806.1). The database was also used to determine the total number of servicemembers within the military during the same period. The incidence of cervical spine fractures and fractures associated with SCI was determined, and unadjusted incidence rates were calculated for the demographic characteristics of sex, race, military rank, branch of service, and age. Adjusted incidence rate ratios were then determined using multivariate Poisson regression analysis to control for other factors in the model and identify significant risk factors for cervical spine fractures and cervical injuries associated with SCI.Results: From 2000 to 2009, there were 4,048 cervical spine fractures in a population at risk of 13,813,333 servicemembers. The overall incidence of cervical spine fractures was 0.29 per 1,000 person-years, and the incidence of fracture associated SCI was 70 per 1,000,000. The cohorts at highest risk of cervical spine fracture were males, whites, Enlisted personnel, those serving in the Army, Navy, or Marine Corps, and servicemembers aged 20 to 29. Risk of fracture-associated SCI was significantly increased in males, Enlisted personnel, servicemembers in the Army, Navy, or Marines, and those aged 20 to 29.Conclusions: This study is the largest population-based investigation to be conducted within the United States regarding the incidence of SCI and the only study addressing incidence and risk factors for cervical spine fractures. Male sex, white race, Enlisted military rank, service in the Army, Navy, or Marine Corps, and ages 20 to 29 were found to significantly increase the risk for cervical fractures and/or fracture associated SCI. Our findings support previously published data but also represent best available evidence based on the size and diversity of the population under study.Level of evidence: Prognostic; Level II.

Minimum acceptable outcomes after lumbar spinal fusion - Corrected Proof

Eugene J. Carragee, Ivan Cheng — 2011-02-03

Abstract: Background Context: Defining success after spinal surgery remains problematic. The minimal clinically important difference (MCID) in pain or functional outcomes is a common metric often calculated independent of perceived risk and morbidity, which is an important consideration in large procedures such as spinal fusion and instrumentation.Purpose: The purpose of this study was to describe a method of assessing treatment success based on prospective, patient-reported “minimum acceptable” outcome for which they would undergo a procedure. These goals can then be compared at follow-up to gauge how frequently patient goals are met and determine correlation with patient satisfaction.Study Design: This is a clinical descriptive study of the patient-reported minimum acceptable outcomes for spinal fusion surgery.Outcome Measures: Minimum acceptable outcomes were determined by patients on preoperatively administered standard questionnaires regarding ultimate pain intensity, functional outcome (Oswestry Disability Index [ODI]), medication usage, and work status. Satisfaction with outcomes was assessed at 2-year follow-up.Methods: One hundred sixty-five consecutive patients undergoing lumbar fusion for either isthmic spondylolisthesis or disc degeneration were asked to preoperatively define on standard questionnaires their minimum acceptable outcomes after surgery. Two-year outcomes and satisfaction were subsequently reported and compared with the preoperatively determined minimum acceptable outcomes.Results: Both the spondylolisthesis and the degenerative disc disease (DDD) groups reported that a high degree of improvement was the minimum acceptable threshold for considering spinal fusion. A large majority indicated that the minimum acceptable outcomes included at least a decrease in pain intensity to 3/10 or less, an improvement in ODI of 20 or more, discontinuing opioid medications, and return to some occupational activity. Achieving the minimum acceptable outcome was strongly associated with satisfaction at 2 years after surgery. Patients with compensation claims, psychological distress, and other psychosocial stressors were more likely to report satisfaction in the absence of achieving their minimum acceptable outcome.Conclusions: Patients with spondylolisthesis and DDD both have relatively high minimum acceptable outcomes for spinal fusion. In these cohorts, few subjects considered more commonly proposed MCIDs for pain and function as an acceptable outcome and report that they would not have surgery if they did not expect to achieve more than those marginal improvements. Although there was good concordance between achieving the minimum acceptable outcomes and ultimate satisfaction, patients with significant psychosocial factors (compensation claims, psychological distress, and others) are less likely to associate satisfaction with outcomes with actually achieving these improvements.

Characterization of combat-related spinal injuries sustained by a US Army Brigade Combat Team during Operation Iraqi Freedom - Corrected Proof

Andrew J. Schoenfeld, Gens P. Goodman, Philip J. Belmont — 2010-06-14

Abstract: Background Context: The United States is presently engaged in the largest scale armed conflict since Vietnam. Despite recent investigations into the scope of injuries sustained by soldiers in Iraq and Afghanistan, little information is available regarding the incidence and epidemiology of spine trauma in this population.Purpose: Characterize the incidence and epidemiology of spinal injuries sustained during combat by soldiers of a US Army Brigade Combat Team (BCT) that participated in Operation Iraqi Freedom.Study Design: Descriptive epidemiologic study.Patient Sample: A total of 4,122 soldiers who served in Iraq with an Army BCT during “The Surge” operation.Outcome Measures: Spine injury epidemiology was calculated for the BCT, including the spine combat casualty rate, and percent medically evacuated (MEDEVAC).Methods: Unit rosters were obtained, and a comprehensive database identifying all combat-related spine injuries was created by querying each soldiers' electronic medical record and the unit's casualty rosters. Demographic information was recorded including age, sex, rank, injury mechanism, presence of polytrauma, and injury outcome. Injury outcomes were classified as killed in action, died of wounds, MEDEVAC, or returned to duty. The incidence of spine injuries was determined, and epidemiology was characterized using calculations of the spine combat casualty rate and percent MEDEVAC. Comparisons were made to published reports from previous conflicts.Results: A total of 29 soldiers sustained 31 combat-related spine injuries. These accounted for 7.4% (29 out of 390) of all casualties sustained during combat. Blunt trauma to the spine, often resulting from an explosive mechanism, was encountered in 65% of cases. Closed fractures of the spine occurred in 21% of casualties and open injuries occurred in 7%. The spine combat casualty rate was 5.6 out of 1,000 soldier combat-years, and the percent MEDEVAC was 19%.Conclusions: This investigation is the first of its kind, documenting the nature of spine trauma in a major American conflict. The incidence of spine injuries in this study is the highest ever documented and is indicative of the tactics used by the enemy in the current war. Given this fact, it is likely that the prevalence of combat-related spine trauma will increase in the future. Larger, more extensive, studies of this kind must be conducted in the future.

Back disorders among Israeli youth: a prevalence study in young military recruits - Corrected Proof

2010-06-11

Abstract: BACKGROUND CONTEXT: Back problems are reported with increasing frequency in adults and adolescents. Most information is from self-reported questionnaires or studies with small sample sizes. Reports were usually focused on specific diseases and biased toward overdiagnosis.PURPOSE: To assess the prevalence of common back disorders among a large cohort of 17-year-old males and females recruited by the Israel Defense Forces (IDF).STUDY DESIGN: A retrospective cross-sectional prevalence study.PATIENT SAMPLE: Seventeen-year-old Israeli male and female military recruits reporting as directed by the IDF for preinduction medical examination between January 01, 1998 and December 31, 2006.OUTCOME MEASURES: Military functional limitation Grades 1 to 7 per diagnosis category.METHODS: Military recruits were examined and classified based on medical and orthopedic diagnoses. They were referred for orthopedic consultation as necessary. Four orthopedic classifications were used: spinal deformity (including kyphosis and scoliosis), back pain (including neck and radicular syndromes), spondylolysis/olisthesis, and limitations resulting from trauma or spinal surgery. Data were coded into a central database, and descriptive statistics are presented.RESULTS: The overall prevalence of back disorders among 828,171 17-year-old military recruits (61.5% male) was 16.8%. Back disorders resulting in significant functional limitation were diagnosed in 0.8% of recruits. The most prevalent diagnoses were spinal deformities (kyphosis and scoliosis, females 11.9%, males 11.5%) and back pain (females 3.0%, males 5.6%). Most of these diagnoses were rated as mild.CONCLUSIONS: When using objective criteria, overall back disorders in a large population of 17-year-old recruits were 17%, considerably lower than most reports. Back morbidity severe enough to prevent combat duty occurred at a rate of less than 1%, suggesting that serious back morbidity is not a frequent finding in this age group.LEVEL OF EVIDENCE: Symptom prevalence study, Level III.