The Spine Journal

Preoperative Zung Depression Scale predicts outcome after revision lumbar surgery for adjacent segment disease, recurrent stenosis, and pseudarthrosis

2011-09-22

Abstract: Background context: Persistent back pain and leg pain after index surgery is distressing to patients and spinal surgeons. Revision surgical treatment is technically challenging and has been reported to yield unpredictable outcomes. Recently, affective disorders, such as depression and anxiety, have been considered potential predictors of surgical outcomes across many disease states of chronic pain. There remains a paucity of studies assessing the predictive value of baseline depression on outcomes in the setting of revision spine surgery.Purpose: To assess the predictive value of preoperative depression on 2-year postoperative outcome after revision lumbar surgery for symptomatic pseudarthrosis, adjacent segment disease (ASD), and same-level recurrent stenosis.Study design: Retrospective cohort study.Patient sample: One hundred fifty patients undergoing revision surgery for symptomatic ASD, pseudarthrosis, and same-level recurrent stenosis.Outcome measures: Patient-reported outcome measures were assessed using an outcomes questionnaire that included questions on health-state values (EQ-5D), disability (Oswestry Disability Index [ODI]), pain (visual analog scale), depression (Zung Self-Rating Depression Scale), and 12-Item Short Form Health Survey physical and mental component scores.Methods: One hundred fifty patients undergoing revision neural decompression and instrumented fusion for ASD (n=50), pseudarthrosis (n=47), or same-level recurrent stenosis (n=53) were included in this study. Preoperative Zung Self-Reported Depression Scale score was assessed for all patients. Preoperative and 2-year postoperative visual analog scale for back pain and leg pain scores and ODI were assessed. The association between preoperative Zung Depression Scale score and 2-year improvement in disability was assessed via multivariate regression analysis.Results: Compared to preoperative status, VAS-BP was significantly improved 2 years after surgery for ASD (8.72±1.85 vs. 3.92±2.84, p=.001), pseudoarthrosis (7.31±0.81 vs. 5.06±2.64, p=.001), and same-level recurrent stenosis (9.28±1.00 vs. 5.00±2.94, p=.001). Two-year ODI was also significantly improved after surgery for ASD (28.72±9.64 vs. 18.48±11.31, p=.001), pseudoarthrosis (29.74±5.35 vs. 25.42±6.00, p=.001), and same-level recurrent stenosis (36.01±6.00 vs. 21.75±12.07, p=.001). Independent of age, BMI, symptom duration, smoking, comorbidities, and level of preoperative pain and disability, increasing preoperative Zung depression score was significantly associated with less 2-year improvement in disability (ODI) after revision surgery for ASD, pseudoarthrosis, and recurrent stenosis.Conclusions: Our study suggests that the extent of preoperative depression is an independent predictor of functional outcome after revision lumbar surgery for ASD, pseudoarthrosis, and recurrent stenosis. Future comparative effectiveness studies assessing outcomes after revision lumbar surgery should account for depression as a potential confounder. The Zung depression questionnaire may help risk stratify patients presenting for revision lumbar surgery.

Commentary: Revision lumbar surgery and revisiting the role of preoperative depression screening

Eugene J. Carragee, Connor J. Telles — 2012-03-01

COMMENTARY ON: Adogwa O, Parker SL, Shau DN, et al. Preoperative Zung Depression Scale predicts outcome after revision lumbar surgery for adjacent segment disease, recurrent stenosis, and pseudarthrosis. Spine J 2012;12:179–85 (in this issue).

Health-related quality of life and comorbidities associated with lumbar spinal stenosis

Michele C. Battié, C. Allyson Jones, Donald P. Schopflocher, Richard W. Hu — 2011-12-23

Abstract: Background context: Spinal stenosis is one of the most commonly diagnosed pathologies of the lumbar spine and the leading indication for spine surgery in adults aged 65 years and older. Yet, the burden of lumbar spinal stenosis (LSS) alone, and in combination with common comorbidities, on health-related quality of life (HRQL) is unknown as are comorbidities specifically associated with this chronic condition.Purpose: To estimate the illness burden of LSS on HRQL, adjusting for the effects of specific comorbidities, age, and gender, and investigate whether specific comorbidities are associated with the condition.Study design/setting: A community-based cohort of 245 patients diagnosed with LSS was assembled and compared with a representative sample of 7,489 adults from the base population of Albertans responding to the Canadian Community Health Survey on HRQL and comorbidities.Methods: Health-related quality-of-life data were acquired through interviews for both groups using the Health Utilities Index Mark 3 (HUI3). Both groups were also queried about the presence of 13 specific chronic conditions. Linear regression was used to model HUI3 scores as a function of group, age, gender, and specific comorbid conditions. Logistic regression was used to compare the odds of having particular comorbid conditions between the LSS and general population groups.Results: The mean unadjusted overall HUI3 scores were 0.60 for the LSS group and 0.85 for the general population (1=perfect health). After adjustment, HRQL deficits four times that deemed a clinically important difference remained between the groups. Controlling age and gender, the prevalence of arthritis, migraines, hypertension, and incontinence was significantly greater in the LSS group as compared with the general population sample.Conclusions: Diagnosed LSS is associated with a very substantial burden of illness that is compounded by associated comorbidities, with implications for clinical care, health-care policy decisions, and research. Attention to comorbidities is particularly important in LSS.

Commentary: Lessons and limitations of population-based research

David A. Wong — 2012-03-01

COMMENTARY ON: Battié MC, Jones CA, Schopflocher DP, Hu RW. Health-related quality of life and comorbidities associated with lumbar spinal stenosis. Spine J 2012;12:189–95 (in this issue).

Risk factors for medical complication after spine surgery: a multivariate analysis of 1,591 patients

2012-01-16

Abstract: Background context: Several studies have examined the occurrence of medical complication after spine surgery. However, many of these studies have been done using large national databases. Although these allow for analysis of thousands of patients, potentially influential covariates are not accounted for in these retrospective studies. Furthermore, the accuracy of these retrospective data collection in these databases has been called into question.Purpose: Using multivariate analysis on a prospectively collected data registry to determine significant risk factors for medical complication after spine surgery.Study design: Retrospective multivariate analysis of prospectively collected registry data. The registry is a prospectively collected database of all patients who underwent spine surgery in our two institutions from January 1, 2003 to December 31, 2004.Methods: Extensive demographic and medical information were prospectively recorded as described previously by Mirza et al. Complications were defined in detail a priori, and they were prospectively recorded for at least 2 years after surgery. We analyzed risk factors for medical complication after spine surgery using univariate and multivariate analyses.Results: We analyzed data from 1,591 patients who met out inclusion criteria. The cumulative incidences of complication after spine surgery per organ system are as follows: cardiac, 8.4%; pulmonary, 13%; gastrointestinal, 3.9%; neurological, 7.35%; hematological, 10.75%; and urological complications, 9.18%. The occurrence of cardiac or respiratory complication after spine surgery was significantly associated with death within 2 years (relative risk, 4.11 and 10.76, respectively). Surgical invasiveness and age were significant risk factors for complications in five of the six organ systems evaluated. Individual organ system-specific elative risk values with 95% confidence intervals and p values are listed in Tables 3 and 4.Conclusions: Risk factors identified in this study can be beneficial to clinicians and patients alike when considering surgical treatment of the spine. Future analyses and models that predict the occurrence of medical complication after spine surgery may be of further benefit for surgical decision making.

Commentary: Complications in spine surgery: “the devil is in the details”

Y. Raja Rampersaud — 2012-03-01

COMMENTARY ON: Lee MJ, Konodi MA, Cizik AM, et al. Risk factors for medical complication after spine surgery: a multivariate analysis of 1,591 patients. Spine J 2012;12:197–206 (in this issue).

Comparison of unilateral versus bilateral instrumented transforaminal lumbar interbody fusion in degenerative lumbar diseases

Huaming Xue, Yihui Tu, Minwei Cai — 2012-03-02

Abstract: Background context: Transforaminal lumbar interbody fusion (TLIF) has become a well-established technique that is traditionally performed with bilateral pedicle screw (PS) fixation. There are only a small number of case reports of unilateral instrumented TLIF. To our knowledge, there have been few well-designed studies comparing unilateral versus bilateral instrumentation with TLIF.Purpose: To compare clinical and radiographic outcomes in a selected series of patients treated with unilateral versus bilateral PS instrumented TLIF.Study design: Prospective randomized study in one unit.Patient sample: A total of 80 patients were enrolled in this study. Thirty-seven patients (17 men and 20 women; average age 57.1 years) were randomized to the unilateral PS group and 43 patients (18 men and 25 women; average age 58.2 years) to the bilateral PS group.Outcome measures: The demographic data collected from both groups were gender, age, preoperative index diagnosis, degenerated segment, and single/double level of fusion. Operative time, blood loss, hospital time, and implant costs were also evaluated. Postsurgical pain and functional results were analyzed by the visual analog scale (VAS), modified Prolo (mProlo) scores, and Oswestry Disability Index (ODI). Radiographic examinations were carried out to assess total fusion rates, screw failure, and general complications.Methods: Patients were randomized into the unilateral or bilateral PS instrumented TLIF group based on a computer-generated number list. Patients were asked to return to hospital for follow-up at 4 weeks, 3 months, 6 months, 12 months, and thereafter once a year after surgery.Results: The mean follow-up was 25.3 months, with a range of 18 to 32 months. There were no significant differences between the two groups in terms of demographic data. The unilateral PS group had a significantly shorter operative time, less blood loss, and reduced implant costs compared with the bilateral PS group, although hospital time was the same for double-level cases. The average postoperative VAS, mProlo, and ODI scores improved significantly in both groups, with no significant difference between groups. The total fusion rate, screw failure, and general complication rate were not significantly different.Conclusions: Unilateral PS instrumented TLIF is a viable treatment option generating better results, especially in terms of operative time, blood loss, and hospital time for single-level disease and implant costs. No decrease in the fusion rate or increase in the complication rate was observed in this group. Further improved study design and a longer period of follow-up are needed to confirm this effect.

Commentary: Is bilateral pedicle screw fixation necessary when performing a transforaminal lumbar interbody fusion? An analysis of clinical outcomes, radiographic outcomes, and cost

Jeffrey A. Rihn — 2012-03-01

COMMENTARY ON: Xue H, Tu Y, Cai M. Comparison of unilateral versus bilateral instrumented transforaminal lumbar interbody fusion in degenerative lumbar diseases. Spine J 2012;12:209–15 (in this issue).

Postoperative Infection Treatment Score for the Spine (PITSS): construction and validation of a predictive model to define need for single versus multiple irrigation and debridement for spinal surgical site infection

2012-03-05

Abstract: Background context: There is very little evidence to guide treatment of patients with spinal surgical site infection (SSI) who require irrigation and debridement (I&D) in deciding need for single or multiple I&Ds or more complex wound management such as vacuum-assisted closure dressing or soft-tissue flaps.Purpose: The purpose of this study was to build a predictive model that stratifies patients with spinal SSI, allowing us to determine which patients will need single versus multiple I&D. The model will be validated and will serve as evidence to support a scoring system to guide treatment.Study design: A consecutive series of 128 patients from a tertiary spine center (collected from 1999 to 2005) who required I&D for spinal SSI were studied based on data from a prospectively collected outcomes database.Methods: More than 30 variables were identified by extensive literature review as possible risk factors for SSI and tested as possible predictors of risk for multiple I&D. Logistic regression was conducted to assess each variable's predictability by a “bootstrap” statistical method. A prediction model was built in which single or multiple I&D was treated as the “response” and risk factors as “predictors.” Next, a second series of 34 different patients meeting the same criteria as the first population were studied. External validation of the predictive model was performed by applying the model to the second data set, and predicted probabilities were generated for each patient. Receiver operating characteristic curves were constructed, and the area under the curve (AUC) was calculated.Results: Twenty-four of one hundred twenty-eight patients with spinal SSI required multiple I&D. Six predictors: anatomical location, medical comorbidities, specific microbiology of the SSI, the presence of distant site infection (ie, urinary tract infection or bacteremia), the presence of instrumentation, and the bone graft type proved to be the most reliable predictors of need for multiple I&D. Internal validation of the predictive model yielded an AUC of 0.84. External validation analysis yielded AUC of 0.70 and 95% confidence interval of 0.51 to 0.89. By setting a probability cutoff of .24, the negative predictive value (NPV) for multiple I&D was 0.77 and positive predictive value (PPV) was 0.57. A probability cutoff of .53 yielded a PPV of 0.85 and NPV of 0.46.Conclusions: Patients with positive methicillin-resistant Staphylococcus aureus culture or those with distant site infection such as bacteremia were strong predictors of need for multiple I&D. Presence of instrumentation, location of surgery in the posterior lumbar spine, and use of nonautograft bone graft material predicted multiple I&D. Diabetes also proved to be the most significant medical comorbidity for multiple I&D. The validation of this predictive model revealed excellent PPV and good NPV with appropriately chosen probability cutoff points. This study forms the basis for an evidence-based classification system, the Postoperative Infection Treatment Score for the Spine that stratifies patients who require surgery for SSI, based on specific spine, patient, infection, and surgical factors to assess a low, indeterminate, and high risk for the need for multiple I&D.

Accuracy and complications associated with posterior C1 screw fixation techniques: a radiographic and clinical assessment

2012-03-05

Abstract: Background context: The variable C1 anatomy can make instrumentation challenging and prone to potentially severe complications. New techniques have expanded available options.Purpose: The aims of this study were to evaluate a large series of posterior C1 screws to determine accuracy by computed tomography (CT) scan; assess dimensions of “safe bony windows” with CT; and assess perioperative complication rate related to errant screw placement.Study design: Retrospective review of a single tertiary care spine database to identify patients with C1 instrumentation between December 2002 and September 2008.Patient sample: The sample comprised 176 patients with 344 C1 screws. All 176 patients were assessed for perioperative complications related to their C1 screws. Twenty-nine patients did not have postoperative CT scans, leaving 147 patients with 286 screws for analysis of screw accuracy.Outcome measures: The outcome measures consisted of a radiographic assessment of accuracy of placement of C1 instrumentation and a clinical assessment of perioperative complications related to C1 instrumentation focusing on neurologic and vascular injuries.Methods: Clinical data were obtained from the medical record. Radiographic analyses included preoperative and postoperative CT scans to quantify the patients' bone and classify accuracy of instrumentation. Screws were graded using the following definitions: Type I, screw threads completely within the bone; Type II, less than half the diameter of the screw violates the surrounding cortex; and Type III, clear violation of transverse foramen or spinal canal.Results: One hundred seventy-six patients (97 males and 79 females) underwent posterior C1 screw (lateral mass [LM] or transarticular [TA]) fixation. A total of 344 screws were placed with 216 LM screws and 128 TA screws. Twenty-nine patients (58 screws) did not have postoperative CT scans and were not included for analysis of radiographic accuracy but were included in assessment of complications based on medical records. Ninety-six percent of screws (Type I or II) were rated as “safe,” and 86% of screws were rated as being ideal (Type I). Twelve screws (4%) were unacceptably placed (Type III). There were no known neurologic or vertebral artery injuries. One patient underwent revision surgery for a medially placed screw. Mean C1 LM width was 10.5 mm across all patients. Estimated blood loss averaged 331 mL.Conclusions: Our findings demonstrate a low incidence of complications associated with posterior screw instrumentation of the C1 LM.

Comparative study of fusion rate induced by different dosages of Escherichia coli–derived recombinant human bone morphogenetic protein-2 using hydroxyapatite carrier

2012-02-17

Abstract: Background context: Hydroxyapatite (HA) is considered to be useful because of its high affinity for recombinant human bone morphogenetic protein (rhBMP), mechanical resistance to compressive force, and possible reduction of rhBMP dose.Purpose: To evaluate the osteoinductivity of Escherichia coli–derived rhBMP-2 and the suitability of porous HA as an rhBMP-2 carrier.Study design: In vivo study using microcomputerized tomography (micro-CT) scanning.Patient sample: Seventy-six New Zealand white male rabbits were randomized into a single control group (n=14) without rhBMP-2 and four experimental groups (10 μg, 50 μg, 200 μg, and 500 μg of rhBMP-2; n=14 in each group). The subjects were divided into 3- and 6-week groups.Outcome measures: Outcome was evaluated by radiography, bending test, three-dimensional micro-CT, and histologic examinations.Methods: Bilateral posterolateral fusion was carried out, and rhBMP-2 (0, 10, 50, 200, 500, 1,000, and 2,000 μg) was implanted into the bilateral transverse processes using HA as a carrier.Results: The fusion rates of the 3-week group were 83.3% for 50 and 200 μg of rhBMP-2 and 100% for 500 μg. The improved fusion rates of the 50 μg or higher groups compared with those of control were statistically significant. The fusion rates of the 6-week group were 75% for 10 μg of rhBMP-2 and 100% for 50 μg or higher. Similarly, the improved fusion rates of the 10 μg or higher groups compared with those of control were statistically significant. Significantly higher percent volumes were observed in the 3-week 200 μg of rhBMP-2 group and 6-week 200 μg of rhBMP-2 group than the 3-week HA group and 6-week HA group, respectively. Trabecular thickness was significantly higher in the 3-week 200 μg of rhBMP-2 group than the 3-week HA group. Histologic analysis of the 10 μg group showed bone tissues within the pores from 3 weeks, and this was observed more vividly in the 50, 200, and 500 μg groups. The 6-week 10 μg and 50 μg of rhBMP-2 groups had lower amounts of new tissue but higher portions of complete bone tissue within the HA specimen, along with higher formation of completely reconstituted bone tissues outside HA.Conclusions: Injection of 50 μg or more of E. coli–derived rhBMP-2 into a HA carrier induced earlier bone fusion in the intertransverse process of rabbits, which confirms the excellent bone forming ability of E. coli–derived rhBMP-2 and the suitability of HA as a carrier of rhBMP-2.

Influences of disc degeneration and bone mineral density on the structural properties of lumbar end plates

Yang Hou, Wen Yuan — 2012-02-27

Abstract: Background context: Implants subsidence is a frequent complication of interbody fusion, which can result in pain, deformity, nerve damage, and even failure of surgery. The end plates as the interface between implants and the vertebral bodies play a very important role in sharing the compression on the vertebral bodies. The information on the structural property distribution of the end plate and its relationship with bone mineral density (BMD) and disc degeneration will be of great significance for the reduction in implants subsidence and improvement in related operative procedures to increase the success rate of interbody fusion.Purpose: To investigate the structural property distribution of the lumbar end plate; the effects of disc degeneration on the biomechanical properties of the lumbar end plate; and the relationship between the biomechanical properties of the lumbar end plate and BMD.Study design: A biomechanical study was conducted in human cadaveric lumbar spine models.Methods: Indentation tests were performed at 24 standardized test sites in 120 bony end plates of intact human vertebrae (L1–L5) using a 1.5-mm–diameter, hemispherical indenter at a speed of 0.2mm/s. The failure load at each test site was determined using the load-displacement curve. Disc condition was evaluated using a four-point grading scale and bone density was measured using the lateral dual-energy radiograph absorptiometry scans. All end plates were divided into different disc degeneration groups based on the states of the adjacent degenerative discs and BMD groups according to BMD values of the corresponding vertebral bodies. The experimental results were statistically analyzed using the SPSS 15.0 with the disc degeneration and BMD being considered as independent factor, and the failure loads of the superior and inferior end plates were also compared.Results: The peripheral regions of lumbar end plates were stronger than the central regions (p<.05), with the posterolateral sites in front of vertebral pedicles being the strongest regions. The inferior lumbar end plates were found to be stronger than the superior lumbar end plates (p<.05). The disc degeneration was negatively correlated with the failure loads of the lumbar end plates (rs=−0.563; p<.01). With increasing disc degeneration, the decreases of failure loads were nonuniform across the lumbar end plate, and the central region became weak with little strength change on the end plate periphery. The BMD was positively correlated with the failure loads of the lumbar end plates (rs=0.812; p<.01). The failure loads decreased uniformly across the end plate surfaces as the BMD dropped, and the BMD decrease did not change the structural property distributions of lumbar end plates.Conclusions: Preoperative evaluation of the states of intervertebral discs and BMD of patients is necessary for predicting risks of implants subsidence after interbody fusion. For patients with or without disc degeneration or osteoporosis, the implants should be placed at the peripheral regions, especially the posterolateral sites, to acquire higher mechanical strength to reduce subsidence as much as possible.

Effect of short-term unloading on T2 relaxation time in the lumbar intervertebral disc—in vivo magnetic resonance imaging study at 3.0 tesla

2012-03-01

Abstract: Background context: Diurnal changes in T2 values, indicative for changes in water content, have been reported in the lumbar intervertebral discs. However, data concerning short-term T2 changes are missing.Purpose: The purpose of this study was to investigate the short-term effects of unloading on T2 values in lumbar intervertebral discs in vivo.Study design: Experimental study with repeated measurements of lumbar discs T2 relaxation time during a period of 38 minutes of supine posture.Patient sample: Forty-one patients with acute or chronic low back pain (visual analog scale ≥3).Outcome measures: T2 relaxation time in the intervertebral disc, lumbar lordosis angle, and intervertebral disc height.Methods: Forty-one patients (mean age, 41.6 years) were investigated in the supine position using a 3-tesla magnetic resonance system. Sagittal T2 mapping was performed immediately after unloading and after a mean delay of 38 minutes. No patient movement was allowed between the measurements. One region of interest (ROI) was manually placed in both the anterior and the posterior annulus fibrosus (AF) and three ROIs in the nucleus pulposus (NP).Results: There was a statistically significant decrease in the anterior NP (−2.7 ms; p<.05) and an increase in T2 values in the posterior AF (+3.5 ms; p<.001). Discs with initially low T2 values in the NP showed minor increase in the posterior AF (+1.6 ms; p<.05), whereas a major increase in the posterior AF was found in discs with initially high T2 values in the NP (+6.8 ms; p=.001). Patients examined in the morning showed no differences, but those investigated in the afternoon showed a decrease in the anterior NP (−5.3 ms; p<.05) and an increase in the posterior AF (+7.8 ms; p=.002). No significant differences were observed in other regions. Correlation analysis showed moderate correlations between the time of investigation and T2 changes in the posterior AF (r=0.46; p=.002).Conclusions: A shift of water from the anterior to the posterior disc regions seems to occur after unloading the lumbar spine in the supine position. The clinical relevance of these changes needs to be investigated.

Osteoblasts exhibit a more differentiated phenotype and increased bone morphogenetic protein production on titanium alloy substrates than on poly-ether-ether-ketone

2012-03-19

Abstract: Background context: Multiple biomaterials are clinically available to spine surgeons for performing interbody fusion. Poly-ether-ether-ketone (PEEK) is used frequently for lumbar spine interbody fusion, but alternative materials are also used, including titanium (Ti) alloys. Previously, we showed that osteoblasts exhibit a more differentiated phenotype when grown on machined or grit-blasted titanium aluminum vanadium (Ti6Al4V) alloys with micron-scale roughened surfaces than when grown on smoother Ti6Al4V surfaces or on tissue culture polystyrene (TCPS). We hypothesized that osteoblasts cultured on rough Ti alloy substrates would present a more mature osteoblast phenotype than cells cultured on PEEK, suggesting that textured Ti6Al4V implants may provide a more osteogenic surface for interbody fusion devices.Purpose: The aim of the present study was to compare osteoblast response to smooth Ti6Al4V (sTiAlV) and roughened Ti6Al4V (rTiAlV) with their response to PEEK with respect to differentiation and production of factors associated with osteogenesis.Study design: This in vitro study compared the phenotype of human MG63 osteoblast-like cells cultured on PEEK, sTiAlV, or rTiAlV surfaces and their production of bone morphogenetic proteins (BMPs).Methods: Surface properties of PEEK, sTiAlV, and rTiAlV discs were determined. Human MG63 cells were grown on TCPS and the discs. Confluent cultures were harvested, and cell number, alkaline phosphatase–specific activity, and osteocalcin were measured as indicators of osteoblast maturation. Expression of messenger RNA (mRNA) for BMP2 and BMP4 was measured by real-time polymerase chain reaction. Levels of BMP2, BMP4, and BMP7 proteins were also measured in the conditioned media of the cell cultures.Results: Although roughness measurements for sTiAlV (Sa=0.09±0.01), PEEK (Sa=0.43±0.07), and rTiAlV (Sa=1.81±0.51) varied, substrates had similar contact angles, indicating comparable wettability. Cell morphology differed depending on the surface. Cells cultured on Ti6Al4V had lower cell number and increased alkaline phosphatase specific activity, osteocalcin, BMP2, BMP4, and BMP7 levels in comparison to PEEK. In particular, roughness significantly increased the mRNA levels of BMP2 and BMP4 and secreted levels of BMP4.Conclusions: These data demonstrate that rTiAlV substrates increase osteoblast maturation and produce an osteogenic environment that contains BMP2, BMP4, and BMP7. The results show that modifying surface structure is sufficient to create an osteogenic environment without addition of exogenous factors, which may induce better and faster bone during interbody fusion.

Nerve root herniation into a calcified pseudomeningocele after lumbar laminectomy

Ali Akhaddar, Omar Boulahroud, Mohamed Boucetta — 2012-02-27

A 63-year old man with a prior history of an L4–L5 laminectomy 5 years back presented with weakness of the right foot, sensory loss in the S1 dermatome, and sciatica. Magnetic resonance imaging revealed spinal canal stenosis at the L3–L4 level and a pseudomeningocele at the previous operative site (). An L3–L4 laminectomy and exploration of the pseudomeningocele was performed. The calcified wall of the pseudomeningocele was enlarged with a rongeur. A loop of inflamed nerve root prolapsed and was found adherent to the inner wall of the pseudomeningocele (). The herniated nerve root was separated from the pseudomeningocele and repositioned into the dural sac, and the dural defect was repaired. Postoperatively, the patient reported good resolution of his symptoms. A postoperative pseudomeningocele results from a dural tear and is a well-known complication after lumbar laminectomy. Nerve root herniations into a pseudomeningocele are rare and generally undiagnosed on magnetic resonance imaging .

Subconjunctival hemorrhage as a complication of intraoperative positioning for lumbar spinal surgery

Ali Akhaddar, Mohamed Boucetta — 2012-02-27

A 42-year-old man underwent surgery for a recurrent disc herniation at L4–L5. He was positioned prone for 2 hours of surgery. In the immediate postoperative period, the patient developed a painless subconjunctival hemorrhage in his right eye () with intact visual acuity, normal intraocular pressures, and normal fundoscopic examination. The patient was managed conservatively. Three weeks later, the hemorrhage had resolved spontaneously without sequelae. Subconjunctival hemorrhage is a rare complication of patient positioning for posterior spinal surgery . Despite the impressive physical appearance, the symptoms associated with subconjunctival hemorrhage are typically minor and temporary and do not require treatment. Nevertheless, appropriate ophthalmologic examination is indicated to rule out the possibility of concurrent and more serious ocular injuries.

Cervical pseudarthrosis and lumbar fusion mass

Geoffrey E. Stoker — 2012-02-27

At his request, a 59-year-old man’s body was donated to a local medical school after he died of suspected myocardial infarction. On evaluation in a medical student human anatomy suite, an incompletely healed posterior midline thoracolumbar surgical incision was evident. Dissection revealed a laminectomy defect and solid intertransverse fusion at L2 and L3; segmental pedicle screw-based instrumentation had evidently been removed (). During neck dissection, interbody pseudarthrosis because of incomplete bridging between C3 and C4 was uncovered (). There was coincident robust uncinate hypertrophy, perhaps secondary to the failed fusion ().

Modic type I change may predict rapid progressive, deforming disc degeneration: a prospective 1-year follow-up study. Kerttula L, Luoma K, Vehmas T, Grönblad M, Kääpä E. Eur Spine J 2012 Jan 17. [Epub ahead of print]

2012-03-01

This prospective magnetic resonance imaging (MRI) study in chronic low-back pain (CLBP) patients evaluated the natural course of degenerative lumbar spine changes in relation to Modic 1 type changes (M1) within 1 year.

Clinical decision making in spinal fusion for chronic low back pain. Results of a nationwide survey among spine surgeons. Willems P, de Bie R, Oner C, Castelein R, de Kleuver M. BMJ Open 2011 Dec 21;1(2):e000391. Print 2011

2012-03-01

To assess the use of prognostic patient factors and predictive tests in clinical decision making for spinal fusion in patients with chronic low back pain. Nationwide survey among spine surgeons in the Netherlands.

Minimum clinically important difference in pain, disability, and quality of life after neural decompression and fusion for same-level recurrent lumbar stenosis: understanding clinical versus statistical significance. Parker SL, Mendenhall SK, Shau DN, et al. J Neurosurg Spine 2012 Feb 10. [Epub ahead of print]

2012-03-01

Spine surgery outcome studies rely on patient-reported outcome (PRO) measurements to assess treatment effect, but the extent of improvement in the numerical scores of these questionnaires lacks a direct clinical meaning. Because of this, the concept of a minimum clinically important difference (MCID) has been used to measure the critical threshold needed to achieve clinically relevant treatment effectiveness. As utilization of spinal fusion has increased over the past decade, so has the incidence of same-level recurrent stenosis following index lumbar fusion, which commonly requires revision decompression and fusion. The MCID remains uninvestigated for any PROs in the setting of revision lumbar surgery for this pathology.

MRI findings are more common in selected patients with acute low back pain than controls? Hancock M, Maher C, Macaskill P, Latimer J, Kos W, Pik J. Eur Spine J 2012 Feb;21(2):240–6. Epub 2011 Aug 6

2012-03-01

The purpose of this study is to investigate if lumbar disc pathology identified on MRI scans is more common in patients with acute, likely discogenic, low back pain than matched controls.

The effectiveness of two active interventions compared to self-care advice in employees with non-acute low back symptoms: a randomised, controlled trial with a 4-year follow-up in the occupational health setting. Rantonen J, Luoto S, Vehtari A, et al. Occup Environ Med 2012 Jan;69(1):12–20. Epub 2011 May 20

2012-03-01

Evaluate the effectiveness of two active interventions, aimed at secondary prevention of low back pain (LBP), in occupational health. We performed a survey of LBP (n=2480; response rate 71%) and randomized 143 employees (66% males, 45 years) with LBP over 34mm on VAS into Rehabilitation (n=43), Exercise (n=43) or self-care (n=40) groups. Primary outcomes were LBP, physical impairment (PI) and health-related quality of life (HRQoL) for two years and sickness absence (SA) days during four years (LBP specific, total).

Cost-effectiveness of a classification-based system for sub-acute and chronic low back pain. Apeldoorn AT, Bosmans JE, Ostelo RW, de Vet HC, van Tulder MW. Eur Spine J 2012 Jan 19. [Epub ahead of print]

2012-03-01

Identifying relevant subgroups in patients with low back pain (LBP) is considered important to guide physical therapy practice and to improve outcomes. The aim of the present study was to assess the cost-effectiveness of a modified version of Delitto’s classification-based treatment approach compared with usual physical therapy care in patients with sub-acute and chronic LBP with 1 year follow-up.

The prevalence of defensive orthopaedic imaging: a prospective practice audit in Pennsylvania. Miller RA, Sampson NR, Flynn JM. J Bone Joint Surg Am 2012 Feb 1;94(3):e18 1–6

2012-03-01

Defensive medicine has been identified as an area of wasteful health-care spending. Estimates of its prevalence and its contribution to the cost of defensive practices have varied widely. To date, there has been no prospective evaluation of the use of defensive medicine for musculoskeletal conditions.

Does fear of movement mediate the relationship between pain intensity and disability in patients following whiplash injury? A prospective longitudinal study. Kamper SJ, Maher CG, Menezes Costa Lda C, McAuley JH, Hush JM, Sterling M. Pain 2012;153(1):113–9. Epub 2011 Nov 3

2012-03-01

The aim of this study was to test the capacity of the Fear Avoidance Model to explain the relationship between pain and disability in patients with whiplash-associated disorders. Using the method of Baron and Kenny, we assessed the mediating effect of fear of movement on the cross-sectional and longitudinal relationships between pain and disability. Two hundred and five subjects with neck pain due to a motor vehicle accident provided pain intensity (0 to 10 numerical rating scale), fear of movement (Tampa Scale of Kinesiophobia and Pictorial Fear of Activity Scale) and disability (Neck Disability Index) scores within 4 weeks of their accident, after 3 months, and after 6 months. The analyses were consistent with the Fear Avoidance Model mediating approximately 20% to 40% of the relationship between pain and disability. Contrary to our initial hypothesis, the proportion of the total effect of pain on disability that was mediated by fear of movement did not substantially change as increasing time elapsed after the accident. The proportion mediated was slightly higher when fear of movement was measured by Tampa Scale of Kinesiophobia as compared with Pictorial Fear of Activity Scale. The findings of this study suggest that the Fear Avoidance Model plays a role in explaining a moderate proportion of the relationship between pain and disability after whiplash injury.

Dural repairs with spinal sealants

Emily Jane Woo — 2012-03-01

Dr Epstein and Dr Miscusi have discussed the use of sealants to augment dural closure. The US Food and Drug Administration has not evaluated the safety and effectiveness of Evicel, Tisseel, or BioGlue for duraplasty. As Dr Epstein notes, the Contraindications section of the package insert for BioGlue states that “BioGlue for use in neurosurgery, including use as a dural sealant, is not an approved indication.” Prelicensure clinical trials for drug approval are designed to evaluate a medication’s safety and effectiveness for a specific indication. Off-label use of medications/devices is legal and may reflect the current practice of medicine , but it is important for physicians to appreciate that anecdotal experience—even if published in peer-reviewed journals—lacks the scientific rigor and statistical robustness of controlled clinical trials.

Epstein responds

Nancy E. Epstein — 2012-03-01

Incidental durotomies are reported as occurring in 3.1% of cervical and spinal operations in one series and up to 12.5% for cervical ossification of the posterior longitudinal ligament . The deliberate closure of durotomies occurring during spinal surgery should first use varying combinations of fine sutures, microdural staples (medium), muscle grafts (fat grafts resorb), dural patches, and microfibrillar collagen. Only after the optimal clinical closure has been achieved and confirmed with Valsalva maneuvers should the “sealants” and “fibrin glue” adjuncts be applied.

Miscusi responds

Massimo Miscusi — 2012-03-01

I thank the author for continuing the discussion regarding the use of dural sealants in spine surgery in The Spine Journal . Although it has been correctly reported that the off-label use of BioGlue in United States is legal, it seems appropriate to underline that in Europe, BioGlue has received all the necessary approvals for use in neurosurgery, as documented in the Conformité Européenne mark certificate.

Meetings Calendar

2012-03-01

Editorial Board

2012-03-01

The Spine Journal

Preoperative Zung Depression Scale predicts outcome after revision lumbar surgery for adjacent segment disease, recurrent stenosis, and pseudarthrosis

Commentary: Revision lumbar surgery and revisiting the role of preoperative depression screening

Health-related quality of life and comorbidities associated with lumbar spinal stenosis

Commentary: Lessons and limitations of population-based research

Risk factors for medical complication after spine surgery: a multivariate analysis of 1,591 patients

Commentary: Complications in spine surgery: “the devil is in the details”

Comparison of unilateral versus bilateral instrumented transforaminal lumbar interbody fusion in degenerative lumbar diseases

Commentary: Is bilateral pedicle screw fixation necessary when performing a transforaminal lumbar interbody fusion? An analysis of clinical outcomes, radiographic outcomes, and cost

Postoperative Infection Treatment Score for the Spine (PITSS): construction and validation of a predictive model to define need for single versus multiple irrigation and debridement for spinal surgical site infection

Accuracy and complications associated with posterior C1 screw fixation techniques: a radiographic and clinical assessment

Comparative study of fusion rate induced by different dosages of Escherichia coli–derived recombinant human bone morphogenetic protein-2 using hydroxyapatite carrier

Influences of disc degeneration and bone mineral density on the structural properties of lumbar end plates

Effect of short-term unloading on T2 relaxation time in the lumbar intervertebral disc—in vivo magnetic resonance imaging study at 3.0 tesla

Osteoblasts exhibit a more differentiated phenotype and increased bone morphogenetic protein production on titanium alloy substrates than on poly-ether-ether-ketone

Nerve root herniation into a calcified pseudomeningocele after lumbar laminectomy

Subconjunctival hemorrhage as a complication of intraoperative positioning for lumbar spinal surgery

Cervical pseudarthrosis and lumbar fusion mass

Modic type I change may predict rapid progressive, deforming disc degeneration: a prospective 1-year follow-up study. Kerttula L, Luoma K, Vehmas T, Grönblad M, Kääpä E. Eur Spine J 2012 Jan 17. [Epub ahead of print]

Clinical decision making in spinal fusion for chronic low back pain. Results of a nationwide survey among spine surgeons. Willems P, de Bie R, Oner C, Castelein R, de Kleuver M. BMJ Open 2011 Dec 21;1(2):e000391. Print 2011

MRI findings are more common in selected patients with acute low back pain than controls? Hancock M, Maher C, Macaskill P, Latimer J, Kos W, Pik J. Eur Spine J 2012 Feb;21(2):240–6. Epub 2011 Aug 6

Cost-effectiveness of a classification-based system for sub-acute and chronic low back pain. Apeldoorn AT, Bosmans JE, Ostelo RW, de Vet HC, van Tulder MW. Eur Spine J 2012 Jan 19. [Epub ahead of print]

The prevalence of defensive orthopaedic imaging: a prospective practice audit in Pennsylvania. Miller RA, Sampson NR, Flynn JM. J Bone Joint Surg Am 2012 Feb 1;94(3):e18 1–6

Does fear of movement mediate the relationship between pain intensity and disability in patients following whiplash injury? A prospective longitudinal study. Kamper SJ, Maher CG, Menezes Costa Lda C, McAuley JH, Hush JM, Sterling M. Pain 2012;153(1):113–9. Epub 2011 Nov 3

Dural repairs with spinal sealants

Epstein responds

Miscusi responds

Meetings Calendar

Editorial Board

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