The Spine Journal - Articles in Press

Isolated tuberculosis of the lumbar apophyseal joint - Corrected Proof

Ashwin Avadhani, Ajoy P. Shetty, S. Rajasekaran — 2010-01-25

Abstract: Background Context: Posterior element tuberculosis is rare accounting for only 3% to 5% of all spinal tuberculosis. To our knowledge, no case of isolated facet joint tuberculosis with coronal decompensation has been reported in literature so far.Purpose: The purpose of this study was to describe a case of tuberculous arthritis of the lumbar facet joint and its effect on coronal balance of the spine.Study Design: The study design was a case report.Methods: A 14-year-old boy presented with a 3-month history of back pain without radiation and with normal neurological findings. Computed tomography and magnetic resonance imaging showed destruction of the right L4–L5 facet joint with L5–S1 spondylolytic listhesis. Despite 2 months of antitubercular medication after a core biopsy confirmation of L4–L5 facet tuberculosis, there was progression of coronal decompensation of the spine with severe pain. Instrumentation with intertransverse fusion was done as a secondary procedure.Results: The patient was completely relieved of symptoms after instrumented fusion along with antitubercular medication.Conclusion: Isolated lumbar facet joint tuberculosis is a rare entity with a potential for coronal decompensation of the spine, which makes early instrumented fusion with antitubercular medication a viable treatment modality.

Causal assessment of occupational sitting and low back pain: results of a systematic review - Corrected Proof

Darren M. Roffey, Eugene K. Wai, Paul Bishop, Brian K. Kwon, Simon Dagenais — 2010-01-25

Abstract: Background Context: Low back pain (LBP) is a common and disabling musculoskeletal disorder that often occurs in a working-age population. Determining the precise causation of LBP remains difficult. Any attempt to implicate a specific occupational activity in the genesis of LBP requires a methodologically rigorous approach.Purpose: To conduct a systematic review of the scientific literature focused on evaluating the causal relationship between occupational sitting and LBP.Study Design: Systematic review of the literature using Medline, EMBASE, CINAHL, Cochrane Library, Occupational Safety and Health database, grey literature, hand-searching occupational health journals, reference lists of included studies, and content experts. Evaluation of study quality using a modified version of the Newcastle-Ottawa Scale. Summary levels of evidence supporting Bradford-Hill criteria for different categories of sitting and types of LBP.Samples: Studies reporting an association between occupational sitting and LBP.Outcome Measures: Numerical association between different levels of exposure to occupational sitting and the presence or severity of LBP.Methods: A systematic review was performed to identify, evaluate, and summarize the literature related to establishing a causal relationship, according to Bradford-Hill criteria, between occupational sitting and LBP.Results: This search yielded 2,766 citations. Twenty-four studies met the inclusion/exclusion criteria and five were high-quality studies, including two case-controls and three prospective cohorts. Strong, consistent evidence was found for no association between occupational sitting and LBP. A moderate level of evidence was found for the absence of any dose-response trend. Risk estimates evaluating temporality were not statistically significant. Biological plausibility was not discussed in these studies. No evidence was available to assess the experiment criterion.Conclusions: This review failed to uncover high-quality studies to support any of the Bradford-Hill criteria to establish causality between occupational sitting and LBP. Strong and consistent evidence did not support criteria for association, temporality, and dose response. Based on these results, it is unlikely that occupational sitting is independently causative of LBP in the populations of workers studied.

Biomimetic calcium phosphate coatings as bone morphogenetic protein delivery systems in spinal fusion - Corrected Proof

2010-01-25

Abstract: Background Context: Use of recombinant human bone morphogenetic protein-2 (rhBMP-2) has been shown to enhance spinal fusion rates. Case reports of soft-tissue swelling, ectopic bone formation, and osteolysis have recently surfaced. It is hypothesized that incorporation of rhBMP-2 within a calcium phosphate (CaP) coating may help to localize delivery and mitigate these complications.Purpose: To compare the characteristics of posterolateral fusion between rabbits receiving rhBMP-2 delivered via physical adsorption to a collagen sponge or rhBMP-2 incorporated within the physical structure of a CaP coating on a collagen sponge.Study Design/Setting: New Zealand white rabbit model of posterolateral lumbar fusion at L5–L6.Methods: Eighteen (18) New Zealand white rabbits underwent posterolateral spinal fusion at L5–L6. Rabbits received bilateral collagen sponges that were either coated with CaP (n=3), coated with CaP and dipped in rhBMP-2 (n=3), coated with a hybrid CaP–rhBMP-2 film (n=6), or coated with a hybrid CaP-rhBMP-2 film and dipped in rhBMP-2 (n=6). Animals were followed weekly with radiographs and were sacrificed at 6 weeks. Fusion masses were further characterized by manual palpation, computed tomography, and histology.Results: Radiographic evaluation showed that animals in Group 3 (incorporated BMP) fused at 4 weeks, whereas animals in Group 2 (adsorbed BMP) and Group 4 (incorporated and adsorbed BMP) fused by 6 weeks. Animals that received rhBMP-2 physically adsorbed to the collagen sponge showed extension of the fusion mass beyond the L5–L6 level in 56% of cases and bone resorption in 78%. Histology of fusion masses showed mature bone formation in animals belonging to Groups 2, 3, and 4 and extensive osteoclast recruitment in animals belonging to Groups 2 and 4.Conclusions: Delivery of rhBMP-2 via incorporation within CaP coatings results in increased rates of radiographic fusion. The burst release profile of rhBMP-2 adsorbed to surfaces, although effective in achieving fusion, may result in increased osteoclast recruitment.

Surgical site infection after osteotomy of the adult spine: does type of osteotomy matter? - Corrected Proof

Albert F. Pull ter Gunne, C.J.H.M. van Laarhoven, David B. Cohen — 2010-01-18

Abstract: Objective: The objective of the study was to assess the incidence and identify significant risk factors for surgical site infection (SSI) after spinal osteotomy.Summary of Data: Surgical site infection after spinal surgery is frequently seen. It occurs between 0.7% and 12% of patients, leading to higher morbidity, mortality, and health-care costs. Osteotomy procedures are known to have increased blood losses and surgical times when compared with other spinal surgeries. Both of these factors have previously been identified as significant risk factors for SSI. We performed a cohort study of this high-risk population to identify risk factors and rates of SSI after spinal osteotomy surgery and identify difference in risk between different types of osteotomies.Study Design: Retrospective review of all adult patients who underwent spinal osteotomy surgery for deformity by an orthopedic surgeon in our university.Methods: All electronic records of adult orthopedic patients whom underwent a spinal osteotomy procedure at our department between January 1998 and December 2005 (n=363) were abstracted. During surgery, a pedicle subtraction osteotomy (transpedicular wedge resection), anterior spine osteotomy (resection of anterior and middle columns), posterior Smith-Petersen osteotomy (resection of a portion of the superior and inferior lamina, ligamentum flavum, and the inferior and superior articular processed), or a combined anterior and posterior osteotomy (vertebral column resection [VCR]) (circumferential resection of the vertebrae via either a combined anterior/posterior or posterior-only approach) was performed. Primary outcome measurement was SSI. Subanalysis to deep and superficial SSI was performed.Results: Twenty patients (5.5%) were found to have an SSI, with nine (2.5%) having deep SSI. Analysis showed that patients undergoing VCR (p=.042) had a significant increased risk for deep SSI (11.1%). Obese patients had a significant increased risk (p=.045) for superficial SSI.Conclusions: Vertebral column resection has a significant increased risk for SSI (11.1%) compared with other types of osteotomies (4.1%). When possible, osteotomy techniques that involve less extensive exposures and soft-tissue dissection should be chosen to minimize deep SSI risk. Obese patients should be counseled on weight loss to try minimizing superficial SSI risk.

Computed tomography–evaluated features of spinal degeneration: prevalence, intercorrelation, and association with self-reported low back pain - Corrected Proof

Leonid Kalichman, David H. Kim, Ling Li, Ali Guermazi, David J. Hunter — 2009-12-14

Abstract: Background context: Although the role of radiographic abnormalities in the etiology of nonspecific low back pain (LBP) is unclear, the frequent identification of these features on radiologic studies continues to influence medical decision making.Purpose: The primary purposes of the study were to evaluate the prevalence of lumbar spine degeneration features, evaluated on computed tomography (CT), in a community-based sample and to evaluate the association between lumbar spine degeneration features. The secondary purpose was to evaluate the association between spinal degeneration features and LBP.Study design: This is a cross-sectional community-based study that was an ancillary project to the Framingham Heart Study.Sample: A subset of 187 participants were chosen from the 3,529 participants enrolled in the Framingham Heart Study who underwent multidetector CT scan to assess aortic calcification.Outcome measures: Self-report measures: LBP in the preceding 12 months was evaluated using a Nordic self-report questionnaire. Physiologic measures: Dichotomous variables indicating the presence of intervertebral disc narrowing, facet joint osteoarthritis (OA), spondylolysis, spondylolisthesis, and spinal stenosis and the density (in Hounsfield units) of multifidus and erector spinae muscles were evaluated on CT.Methods: We calculated the prevalence of spinal degeneration features and mean density of multifidus and erector spinae muscles in groups of individuals with and without LBP. Using the χ2 test for dichotomous and t test for continuous variables, we estimated the differences in spinal degeneration parameters between the aforementioned groups. To evaluate the association of spinal degeneration features with age, the prevalence of degeneration features was calculated in four age groups (less than 40, 40–50, 50–60, and 60+ years). We used multiple logistic regression models to examine the association between spinal degeneration features (before and after adjustment for age, sex, and body mass index [BMI]) and LBP, and between all degeneration features and LBP.Results: In total, 104 men and 83 women, with a mean age (±standard deviation) of 52.6±10.8 years, participated in the study. There was a high prevalence of intervertebral disc narrowing (63.9%), facet joint OA (64.5%), and spondylolysis (11.5%) in the studied sample. When all spinal degeneration features as well as age, sex, and BMI were factored in stepwise fashion into a multiple logistic regression model, only spinal stenosis showed statistically significant association with LBP, odds ratio (OR) (95% confidence interval [CI]): 3.45 [1.12–10.68]. Significant association was found between facet joint OA and low density of multifidus (OR [95% CI]: 3.68 [1.36–9.97]) and erector spinae (OR [95% CI]: 2.80 [1.10–7.16]) muscles.Conclusions: Degenerative features of the lumbar spine were extremely prevalent in this community-based sample. The only degenerative feature associated with self-reported LBP was spinal stenosis. Other degenerative features appear to be unassociated with LBP.

Determination of the in vivo posterior loading environment of the Coflex interlaminar-interspinous implant - Corrected Proof

2009-12-11

Abstract: Background Context: The in vivo loading environment of load-bearing implants is generally largely unknown. Loads are typically approximated from cadaver tests or biomechanical calculations for the preclinical assessment of a device's safety and efficacy.Purpose: To determine the actual in vivo loading environment of an elastic interlaminar-interspinous implant (Coflex).Study Design: A retrospective radiographic study to noninvasively measure the in vivo implant loads of 176 patients.Methods: For this study, neutral, flexion, and extension radiographs were quantitatively analyzed using validated image analysis technology. The angle between the Coflex arms was measured for each radiograph and statistically evaluated. Separately, the Coflex implant was characterized using mechanical test data and finite element analysis, which resulted in a load-deformation formula that describes the implant load as a function of its size and elastic deformation. Using the formula and the elastic implant deformation data obtained from the radiographic analysis, the exact implant load was calculated for each patient and each posture. For statistical analysis, the patients were grouped by indication and procedure, which resulted in 12 different groups. The determined loads were compared with the strength of the posterior lumbar spinal elements obtained from the literature and with the static and dynamic mechanical limits of the Coflex interlaminar-interspinous implant.Results: The force data were independent of implant size, diagnosis (with one exception), number of levels of the decompression procedure, number of levels of implantations (one or two), and follow-up time. The median compressive force acting on the Coflex implant was found to be 45.8 N. The maximum load change between flexion and extension was 140 N; the maximum overall load exceeded 239 N in extension.Conclusions: The average loads exerted by the Coflex implant on the spinous process and lamina are 11.3% and 7.0% of their respective static failure load. The implant fatigue strength is significantly higher than the measured median force, which explains the extremely rare observation of a Coflex fatigue failure.

Comparison of anterior cervical fusion after two-level discectomy or single-level corpectomy: sagittal alignment, cervical lordosis, graft collapse, and adjacent-level ossification - Corrected Proof

Yung Park, Takeshi Maeda, Woojin Cho, K. Daniel Riew — 2009-10-22

Abstract: Background context: Single-level corpectomy and two-level discectomy with anterior cervical plating have been reported to have comparable fusion and complication rates. However, there are few large series that have compared the two for sagittal alignment, cervical lordosis, graft subsidence, and adjacent-level ossification.Purpose: To determine the differences between these two procedures for patients with two-level spondylosis by comparing the pre- and postoperative radiographic data.Study design: Retrospective review of prospectively collected data in an academic institution.Patient sample: Fifty-two with a single-level corpectomy and 45 with a two-level anterior cervical discectomy and fusion (ACDF).Outcome measures: Pre- and postoperative radiographic data for sagittal alignment, cervical lordosis, subsidence, and adjacent-level ossification.Methods: We retrospectively reviewed the lateral cervical radiographs of patients who had a solid fusion after a single-level cervical corpectomy or a two-level ACDF for the treatment of a degenerative cervical spondylosis by a surgeon at an academic institution. The choice of the operation was dependent on the presence or absence of retrovertebral compression. All patients underwent anterior cervical fusion using fibula strut allograft and variable-angle screw-plate fixation. None had had prior cervical spine surgery. Twenty-five were excluded because of inadequate radiographs and follow-up. There were 52 with a single-level corpectomy and 45 with a two-level ACDF. The following were analyzed: 1) sagittal alignment (modified method of Toyama); 2) cervical lordosis measured by Cobb angles of fusion constructs (fusion Cobb) and C2–C7 (C2–C7 Cobb); 3) graft collapse determined by the subsidence of anterior/posterior body height of fused segments (anterior/posterior subsidence) and the cranial/caudal plate-to-disc distances (cranial/caudal subsidence), and the difference between anterior and posterior body height for the fused levels (anteroposterior [AP] difference); and 4) the severity of ossification at two adjacent levels.Results: The mean durations of follow-up were 23.3±6.6 (corpectomy) and 25.7±6.2 (ACDF) months, range 12 to 45 months. There were no significant differences between the two groups in sagittal alignment, cervical lordosis, graft collapse, and adjacent-level ossification. Graft subsidence and loss of cervical lordosis occurred significantly more during the first 6 weeks after surgery (all measurements, p<.0001) than after 6 weeks, with no significant difference between the two groups. Posterior and caudal end plate subsidence significantly progressed after 6 weeks in Group 1 (p=.04, p=.02). The final follow-up Cobb angle positively correlated with preoperative and immediate postoperative Cobb angles (r=0.437, p<.0001; r=0.727, p<.0001), caudal subsidence (r=0.270, p=.008), and the final AP difference (r=0.915, p<.0001) but did not correlate with surgery level, preoperative and final sagittal alignments, anterior/posterior subsidence, and cranial subsidence. Anterior/posterior subsidence was significantly more strongly related with caudal subsidence (r=0.607, p<.0001; r=0.424, p<.0001) than cranial (r=0.277, p=.007; r=0.211, p=.040) but did not correlate with pre- and postoperative fusion Cobb, and preoperative and the last sagittal alignments.Conclusions: Our data suggest that the two procedures yield comparable results in terms of sagittal alignment, cervical lordosis, graft subsidence, and adjacent-level ossification. Graft subsidence and loss of cervical lordosis appeared to occur mainly during the first 6 weeks after surgery. Single-level corpectomy and fusion continued to subside at the posterior portion of caudal end plate even after 6 weeks. On the other hand, graft subsidence did not correlate with preoperative and final postoperative sagittal alignments.

SWISSspine—a nationwide health technology assessment registry for balloon kyphoplasty: methodology and first results - Corrected Proof

2009-10-12

Abstract: Background Context: The Swiss Federal Office of Public Health demanded a nationwide health technology assessment registry for cervical and lumbar total disc arthroplasty and for balloon kyphoplasty (BKP) to make a decision about reimbursement of these interventions.Purpose: The goal of the SWISSspine registry is to generate evidence about the safety and effectiveness of these technologies. We report on results of patients with balloon kyphoplasty.Study Design/Setting: Prospective, multicenter, observational case series.Patient Sample: From March 2005 until June 2008, 331 interventions with 391 treated levels in 320 patients have been documented. 75.6% of patients were females with mean age of 74 years (range 43–95.2 years); mean age of males was 72.6 years (range 41.4–93 years).Outcome Measures: Surgeon-administered outcome instruments were primary intervention form for BKP, implant, and follow-up form; patient self-reported measures were Euroqol-5D, North American Spine Society, and a comorbidity questionnaire.Methods: Data were recorded perioperative, at 3 months, 1 year, and annually thereafter. Wilcoxon signed-rank test was used for comparison of preoperative to postoperative measurements. Multivariate regression was used for identifying factors with a significant influence on the outcome.Results: Significant and clinically relevant reduction of back pain, improvement of quality of life (QoL), and reduction of pain killer consumption were seen in the 1-year follow-up. Improvement of preoperative segmental kyphosis was achieved in the majority of cases. There were three symptomatic cement extrusions with radiculopathy documented.Conclusions: Balloon kyphoplasty is a safe and effective treatment concerning pain reduction, QoL improvement, and pain killer consumption. The SWISSspine registry proved to be an excellent tool for evaluation of this new technology, and its results, in combination with an elaborate health technology assessment report, led to a permanent coverage of BKP by the basic health insurance.

North American Spine Society: Newly released vertebroplasty randomized controlled trials: a tale of two trials - Corrected Proof

2009-10-12

This commentary is a product of the North American Spine Society (NASS). It was approved by the NASS Board of Directors and accepted for publication outside The Spine Journal's peer review process.

REMOVED: In defense of King et al.: the validity of manual examination in assessing patients with neck pain - Corrected Proof

Nikolai Bogduk — 2008-11-10

This article has been removed consistent with Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The Publisher apologizes for any inconvenience this may cause.

Evaluation of five scoring systems for cervical spondylogenic myelopathy - Corrected Proof

Kristina Dalitz, Hans-Ekkehart Vitzthum — 2008-09-09

Abstract: Background context: Comparison of measured clinical deficits and outcomes is vital for international discussion about the identification and treatment of cervical spondylotic myelopathy (CSM). There is currently little information comparing outcomes as assessed by different CSM scoring systems.Purpose: To qualitatively and quantitatively analyze five specific CSM outcome scores that are frequently used to assess the grade of severity and outcome after operative decompression.Study design: This retrospective study evaluated the Nurick score, the Japanese Orthopedic Association score (JOA score), the Cooper myelopathy scale (CMS), the Prolo score, and the European myelopathy score (EMS).Patient sample: The study included 43 patients with clinical and morphological signs of CSM, who underwent ventral decompression. Data were evaluated in sufficient detail to objectively assess the scores.Outcome measures: Clinical findings (funicular and radicular symptoms), recovery rate, symptom duration, age, economic situation, time away from employment, somatic-evoked potentials, and radiological findings were assessed.Methods: Scores were assessed using both pre- and postoperative clinical data. Correlations between scores, score improvement, and how well the scores reflected the clinical, diagnostic, and anamnestic data were analyzed using nonparametric, descriptive statistical tests. The recovery rate, as a measure of cumulative outcome, was also assessed and compared for each scoring system.Results: All five scores were suitable for qualitatively assessing the clinical characteristics and progression of cervical myelopathy. All showed a statistically significant correlation (p<.05), and measured postoperative improvement (p<.001). All scores also reflected clinical deficits except for the Prolo score, which rates the severity of CSM with an emphasis on data related to the economic impact on the patient's situation rather than on clinical symptoms per se. Quantitative assessment of clinical symptom improvement varied greatly among the scores, for example, Nurick score (33%) versus JOA score (81%). The recovery rates, as a measure of cumulative improvement, showed less variation among most of the scores. The Nurick score and the EMS measured clinical deficit improvements in significantly fewer patients than did the JOA score (p<.05).Conclusions: Evaluating the recovery rate is essential for comparing the results of the five CSM scores evaluated in this study. There was a large quantitative difference among the scores as the result of the different criteria used to produce each score. Qualitatively, all five scores allowed evaluation of cervical myelopathy, but only the recovery rate allowed for statistical comparison. Advancements in the treatment of CSM depend on the ability of clinicians to evaluate the therapeutic results of CSM studies. This study suggests that using the recovery rate to assess outcome is best for comparing studies that use different scores.