Yoga Raja Rampersaud

Heterotopic bone formation with the use of rhBMP2 in posterior minimal access interbody fusion: a CT analysis.

Study Design. Observational study with prospective CT analysis. Objective. To assess the incidence and clinical sequelae of epidural bone formation following the adjunctive use of recombinant bone morphogenetic protein 2 (rhBMP2) with local autogenous bone graft use of (rhBMP2) in minimal access interbody (PLIF and TLIF) fusions. Summary of Background Data. The use of rhBMP2 for interbody fusion is associated with high fusion rates. However, for posterior approaches, concerns regarding heterotopic bone formation within the epidural space have been raised. Methods. An independent CT analysis of 33 consecutive patients following minimal access lumbar fusion (PLIF [n = 10] or TLIF [n = 23]) with [n = 23] and without [n = 10] rhBMP2 was performed. Bone formation was graded in a centrifugal manner (intradiscal, anular/ALL/PLL, epidural [canal/foramen] and beyond the spine). In all BMP cases, a constant dose of 4.2 mg/disc level was administered (lowest commercially available dose). In all cases, local autograft was used. Review and assessment of prospectively collected outcomes data were performed. Results. Average clinical and CT (minimum 6 months) follow-up was 25.0 and 7.9 months, respectively. Bridging bone (fusion) was seen in 100% of the BMP group and 90% without BMP. Epidural bone formation occurred in 20.8% with the use of BMP (5 levels: n = 1 spinal canal and n = 4 within the foramen) compared with 8.3% (1 level: canal) without BMP. Foraminal bone formation was seen only in the TLIF group. All epidural bone formation was heterotopic, and no ectopic bone formation occurred. There were no clinical sequelae associated with heterotopic bone formation. The mean preoperative and postoperative Oswestry Disability Index was 50.2% (range, 25%–75%) and 11.3% (range, 0%–38%) respectively. Conclusion. Although the adjunctive use of rhBMP2 is associated with a higher incidence of heterotopic bone, there does not seem to be any associated clinical sequelae.

Intraoperative multimodality monitoring in adult spinal deformity: analysis of a prospective series of one hundred two cases with independent evaluation.

Study Design. A retrospective analysis of prospectively collected data of 102 consecutive adult patients who underwent intraoperative neurophysiological monitoring (IOM) during spinal deformity corrective surgery. Objective. To report the sensitivity and specificity of combined IOM in this study population using the postoperative neurologic examination as the “gold standard.” Summary of Background Data. IOM is recommended during corrective spinal surgery and has been widely used in the pediatric deformity population. However, there are limited data describing the application of IOM in adults undergoing spinal deformity corrective surgery. Methods. The study group consisted of 102 patients undergoing spinal deformity corrective surgery between 2001 and 2004. Patients were monitored using at least 2 or more electrophysiological methods including somatosensory-evoked potentials (SSEP), motor-evoked potentials (MEP), and electromyography (EMG). Results. The mean age of patients was 41.5 years (±17). The majority of the operative procedures involved instrumented fusion from thoracic to lumbar/sacral spine (n = 55), thoracic-pelvis fusion (n = 26), and a combined total of 32 osteotomies (including 25 pedicle subtraction osteotomies and 7 Smith-Peterson osteotomies). SSEPs were recorded successfully in 101 (99%), EMGs in 89 of 102 (87%), and MEPs in 12 of 16 (75%). Five cases were true positives (4.95%), and these were all detected by combined monitoring (2-SSEP, 2-EMG, 1-MEP). There were no false positives with SSEPs, but EMG resulted in 30 of 89 (34%) false positives. There were 4 false negatives with SSEPs, which reduced its sensitivity to 33%. There was 1 false negative with EMG, and 0 with MEPs. When these results were collated, the overall sensitivity of combined multimodality IOM in this adult deformity series was 100%, specificity 84.3%, PPV 13.9%, and NPV 97%. The combined sensitivity in the osteotomy group (n = 32) was 67%, specificity 98%, PPV 80%, and NPV 96%. In comparison, there were no IOM abnormalities in those patients who had in situ/minor corrective procedures (n = 18; largely adult degenerative scoliosis). Conclusion. Multimodality IOM of spinal cord sensory and motor function during surgical correction of adult spinal deformity is feasible and provides useful neurophysiological data with an overall sensitivity of 100% and a specificity of 84.3% (67% and 98%, respectively in patients undergoing major deformity correction).

The use of C1 lateral mass screws in complex cervical spine surgery: indications, techniques, and outcome in a prospective consecutive series of 25 cases.

Objectives Direct C1 lateral mass/C2 pars or pedicle screw fixation has been recently proposed as an alternative method to C1-C2 transarticular screw fixation. Although this method seems attractive, there are currently limited clinical data on the use of this technique for multilevel fixation including complex craniocervical reconstructions. The objectives of this study were to assess the safety and the clinical/radiographic outcomes in patients undergoing cervical spine surgery using C1 lateral mass screws (C1-LMS). Methods A prospectively accrued database was reviewed to determine initial presentation, etiology, operations, complications, and clinical/radiologic outcomes. Results Twenty-five patients with a mean age of 56 underwent fixation with C1-LMS. Mean follow-up was 12 months. The indications for using C1-LMS instead of C1-C2 transarticular screws were: unfavorable bony or vascular anatomy, tumor destruction, thoracic kyphosis or cervical hyperlordosis, inability to reduce the C1-C2 dislocation intraoperatively and or surgeon preference. Satisfactory stability was achieved in all cases with no neurologic or vascular complications. In one case, the C1 screws breached the medial cortex. Three patients developed transient postoperative C2 neuralgia. One patient had an extended stay in ICU due to respiratory issues. Conclusions On the basis of our experience, proficiency with the use of C1-LMS screw fixation greatly enhances the ability to manage complex atlantoaxial or craniocervical pathologies with low morbidity. This technique should be considered an excellent adjunct or alternative to transarticular screw fixation.

Success and failure of minimally invasive decompression for focal lumbar spinal stenosis in patients with and without deformity.

Study Design. Observational cohort study. Retrospective review of prospectively collected outcomes data. Objective. The purpose of this study was to evaluate the clinical efficacy of minimally invasive (MIS) decompression for focal lumbar spinal stenosis (FLSS) in patients with and without deformity. Summary of Background Data. MIS, facet-preserving decompression has the potential of offering a significantly less morbid alternative to decompression and fusion in patients with leg dominant symptoms from degenerative spondylolisthesis and/or scoliosis. Methods. Single surgeon, consecutive series (n = 75), evaluated over 5 years. All patients had MIS lumbar laminoplasty (bilateral decompression from a unilateral approach) for FLSS (1–2 level). Patients had leg dominant, claudicant/radicular pain. Patients were divided into 4 groups: (A) stenosis with no deformity, n = 22; (B) stenosis with spondylolisthesis only, n = 25; (C) stenosis with scoliosis, n = 16; and (D) stenosis combined with spondylolisthesis and scoliosis, n = 12. The primary clinical outcome measures were the Oswestry Disability Index (ODI) and surgical revision rate. Preoperative and postoperative standing radiographs were assessed. Results. The average age was 68 years (40–89) with a mean time from surgery of 36.5 months (18–68). Average clinical improvement in ODI was 49.5% to 23.9% [mean postoperative follow-up of 31.8 months (24–72): group A = mean of 34.6; B = 28.9; C = 32.7; D = 30 months]. Incidence of preoperative grade I spondylolisthesis was 46%. Spondylolisthesis progression (mean = 8.4%) occurred in 9 patients and 2 patients developed spondylolisthesis. Overall revision rate was 10% [repeat decompression alone (n = 2) and decompression and fusion (n = 6)]. Subgroup analysis of preoperative and postoperative ODI and revision rate revealed (A) 48% to 18.7%, 0%; (B) 48% to 24.6%, 4%; (C) 50.7% to 31.5%; 25%; and (D) 53% to 22%, 25%, respectively. The revision rate for patient with scoliosis (C + D) was significant (P = 0.0035) compared with those without. Six of the 8 revised patients had a preoperative lateral (rotatory) listhesis (3 in C and 3 in D). Conclusion. MIS decompression alone for leg dominant symptoms is a clinically effective procedure in the majority of patients including those with degenerative spondylolisthesis or scoliosis. However, patients with scoliosis, particularly those with lateral listhesis, have a significantly higher revision rate that needs to be considered in operative decision-making.

Nonoperative treatment of lumbar spinal stenosis with neurogenic claudication: a systematic review.

Study Design. Systematic review. Objective. To systematically review the evidence for the effectiveness of nonoperative treatment of lumbar spinal stenosis with neurogenic claudication. Summary of Background Data. Neurogenic claudication can significantly impact functional ability, quality of life, and independence in the elderly. Methods. We searched CENTRAL, MEDLINE, EMBASE, CINAHL, and ICL databases up to January 2011 for randomized controlled trials published in English, in which at least 1 arm provided data on nonoperative treatments. Risk of bias in each study was independently assessed by 2 reviewers using 12 criteria. Quality of the evidence was evaluated using Grades of Recommendations, Assessment, Development, and Evaluation (GRADE). Results. From the 8635 citations screened, 56 were assessed and 21 trials with 1851 participants were selected. There is very low-quality evidence from 6 trials that calcitonin is no better than placebo or paracetamol, regardless of mode of administration or outcome. From single small trials, there is low-quality evidence that prostaglandins, and very low-quality evidence that gabapentin or methylcobalamin, improve walking distance. There is very low-quality evidence from a single trial that epidural steroid injections improve pain, function, and quality of life up to 2 weeks compared with home exercise or inpatient physical therapy. There is low-quality evidence from a single trial that exercise is of short-term benefit for leg pain and function compared with no treatment. There is low- and very low-quality evidence from 6 trials that multimodal nonoperative treatment is less effective than indirect or direct surgical decompression with or without fusion. Conclusion. Moderate- and high-GRADE evidence for nonoperative treatment is lacking and thus prohibiting recommendations to guide clinical practice. Given the expected exponential rise in the prevalence of lumbar spinal stenosis with neurogenic claudication, large high-quality trials are urgently needed.

Spine adverse events severity system: content validation and interobserver reliability assessment.

Study Design. A prospective validation study, preliminary single-center report. Objective. The purpose of this study was to assess the content validity and interobserver reliability of a simple severity classification system for adverse events (AEs) associated with spinal surgery. Summary of Background Data. In the surgical literature what is defined as an AE, the severity of an AE, and the reporting of AEs are variable. Consequently, valid comparison of AEs within or among specialties or surgical centers for the same or different procedures is often impossible. Methods. ince 2002, a Spine Adverse Events Severity system (SAVES) has been locally developed and prospectively used. AEs were graded as I (requires none/minimal treatment, minimal effect [<1–2 days] on length of stay [LOS]), II (requires treatment and/or increases LOS [3–7 days] with no long-term sequelae), III (requires treatment and/or increased LOS [>7 days] with long-term sequelae [>6 months]), and IV (death). Content validity of the grading system was assessed using the hospital chart abstraction (current defacto gold standard) compared with the SAVES from 200 randomly selected patients. Interobserver reliability was assessed in consecutive operative cases for 1 spine surgeon during a 1-year period (2006) using 3 raters (staff surgeon, fellow, and/or resident). Results. The prospectively administered form reported a higher number of surgical AEs (n = 43 vs. n = 30) and a similar number of medical AEs (n = 31 vs. n = 27). Compared with the chart, the AE form displayed substantial agreement for number (70%; weighted Kappa [wK] = 0.60) and type (75%; wK = 0.67) of AE. The interobserver reliability was near perfect (kappa = 0.8) for the actual grade of AE and moderate (kappa = 0.5) for the criteria behind the grading (i.e., clinical effect of the AE or the effect of the AE on LOS or both). Conclusion. The result of this study demonstrates improved capture of surgical AEs using SAVES. Excellent interobserver reliability between surgeons at different level of training was demonstrated with minimal education or training regarding the use of SAVES.

Fluoroscopic computer-assisted pedicle screw placement through a mature fusion mass: an assessment of 24 consecutive cases with independent analysis of computed tomography and clinical data.

Study Design. Observational matched cohort study with computed tomography (CT) analysis of pedicle screw placement. Objective. Assess the clinical accuracy of computer-assisted fluoroscopy for the placement of thoracolumbar pedicle screws through a mature posterolateral fusion mass. Summary of Background Data. Pedicle screw placement through an amorphous posterolateral fusion mass intuitively carries a higher risk of pedicle wall violation. Methods. Postoperative CT scans of 102 pedicle screws placed through a mature posterolateral fusion mass (n = 10 [T10–T12]; n = 92 [L1–S1]) were independently assessed and compared with a matched control (nonobscured anatomy) group. All screws were placed before any decompression using the FluoroNav system. Results. In the fusion mass group, overall 81.4% of screws were completely within the pedicle. Seven medial and 12 lateral pedicle breaches occurred. Relative to the total number of screws, pedicle breaches were graded II (<2 mm) in 13.5%, III (2–4 mm) in 2.9%, and IV (>4 mm) in 2.0% of screws. The number and direction of pedicle breaches were not significantly different when compared with the control group. There were no clinically significant screw misplacements in either group. Conclusions. The use of computer-assisted fluoroscopy is safe and effective for the placement of thoracolumbar (T10–S1) pedicle screws through a posterolateral fusion mass without performing laminoforaminotomies.

Perioperative outcomes and adverse events of minimally invasive versus open posterior lumbar fusion: meta-analysis and systematic review

OBJECT The objective of this study was to determine the clinical comparative effectiveness and adverse event rates of posterior minimally invasive surgery (MIS) compared with open transforaminal or posterior lumbar interbody fusion (TLIF/PLIF). METHODS A systematic review of the Medline, EMBASE, PubMed, Web of Science, and Cochrane databases was performed. A hand search of reference lists was conducted. Studies were reviewed by 2 independent assessors to identify randomized controlled trials (RCTs) or comparative cohort studies including at least 10 patients undergoing MIS or open TLIF/PLIF for degenerative lumbar spinal disorders and reporting at least 1 of the following: clinical outcome measure, perioperative clinical or process measure, radiographic outcome, or adverse events. Study quality was assessed using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) protocol. When appropriate, a meta-analysis of outcomes data was conducted. RESULTS The systematic review and reference list search identified 3301 articles, with 26 meeting study inclusion criteria. All studies, including 1 RCT, were of low or very low quality. No significant difference regarding age, sex, surgical levels, or diagnosis was identified between the 2 cohorts (856 patients in the MIS cohort, 806 patients in the open cohort). The meta-analysis revealed changes in the perioperative outcomes of mean estimated blood loss, time to ambulation, and length of stay favoring an MIS approach by 260 ml (p < 0.00001), 3.5 days (p = 0.0006), and 2.9 days (p < 0.00001), respectively. Operative time was not significantly different between the surgical techniques (p = 0.78). There was no significant difference in surgical adverse events (p = 0.97), but MIS cases were significantly less likely to experience medical adverse events (risk ratio [MIS vs open] = 0.39, 95% confidence interval 0.23-0.69, p = 0.001). No difference in nonunion (p = 0.97) or reoperation rates (p = 0.97) was observed. Mean Oswestry Disability Index scores were slightly better in the patients undergoing MIS (n = 346) versus open TLIF/PLIF (n = 346) at a median follow-up time of 24 months (mean difference [MIS - open] = 3.32, p = 0.001). CONCLUSIONS The result of this quantitative systematic review of clinical comparative effectiveness research examining MIS versus open TLIF/PLIF for degenerative lumbar pathology suggests equipoise in patient-reported clinical outcomes. Furthermore, a meta-analysis of adverse event data suggests equivalent rates of surgical complications with lower rates of medical complications in patients undergoing minimally invasive TLIF/PLIF compared with open surgery. The quality of the current comparative evidence is low to very low, with significant inherent bias.

Admission and Acute Complication Rate for Outpatient Lumbar Microdiscectomy

OBJECTIVE Specialization is generally independently associated with improved outcomes for most types of surgery. This is the first study comparing the immediate success of outpatient lumbar microdiscectomy with respect to acute complication and conversion to inpatient rate. Long-term pain relief is not examined in this study. METHODS Two separate prospective databases (one belonging to a neurosurgeon and brain tumor specialist, not specializing in spine (NS) and one belonging to four spine surgeons (SS)) were retrospectively reviewed. All acute complications as well as admission data of patients scheduled for outpatient lumbar microdiscectomy were extracted. RESULTS In total, 269 patients were in the NS group and 137 patients were in the SS group. The NS group averaged 24 cases per year while the SS group averaged 50 cases per year. Chi-square tests revealed no difference in acute complication rate [NS (6.7%), SS (7.3%)] (p > 0.5) and admission rate [NS (4.1%), SS (5.8%)] (p = 0.4) while the SS group had a significantly higher proportion of patients undergoing repeat microdiscectomy [NS (4.1%), SS (37.2%)] (p < 0.0001). Excluding revision operations, there was no statistically significant difference in acute complication [NS (5.4%), SS (1.2%)] (p = 0.09) and conversion to inpatient [NS (4.3%), SS (4.6%)] (p > 0.5) rate. The combined acute complication and conversion to inpatient rate was 6.9% and 4.7% respectively. CONCLUSION Based on this limited study, outpatient lumbar microdiscectomy can be apparently performed safely with similar immediate complication rates by both non-spine specialized neurosurgeons and spine surgeons, even though the trend favored the latter group for both outcome measures.

Posterior column reconstruction with autologous rib graft after en bloc tumor excision.

Study Design. Retrospective review of consecutive case series. Objective. To evaluate the efficacy of using autologous rib graft for fusion across long posterior column defects. Summary of Background Data. Achieving fusion across large posterior column defects after en bloc tumor resection can be difficult. Rib graft can be harvested from the local wound, and its shape and structural properties are well suited for reconstruction of thoracic posterior column deficits. Methods. After Research Ethics Board approval, a retrospective review of the charts of 17 consecutive patients undergoing posterior column reconstruction after en bloc tumor resections was carried out. Autologous vascularized and nonvascularized rib grafts were utilized in 8 and 9 cases, respectively; 14 patients with malignant tumors and 3 with benign etiology. After surgery, patients underwent routine clinical and radiographic follow-up, with a computed tomographic scan performed at a minimum of 6 months in all surviving patients. Clinical and radiographic films were analyzed. Results. Computed tomographic scans at a minimum of 6 months demonstrated graft incorporation in all surviving cases. There was no obvious difference at 6-month imaging to differentiate vascularized from nonvascularized grafts. There were no cases of graft dislodgement or fracture. Graft site morbidity was difficult to isolate from the morbidity of these large procedures. No complications related to the graft were identified. Conclusion. The use of autologous rib graft with a proximal step-cut and distal saddle-cut supplemented with posterior instrumentation allowed immediate stabilization of the posterior column defect created by the en bloc tumor resection. This technique of fashioning the graft and taking advantage of its natural curved structure for immediate press-fit was associated with graft incorporation in our cases.