Should We Label All Synovial Cysts as Unstable?

STUDY DESIGN: Retrospective study. OBJECTIVE: To analyze the various anatomical parameters that influence segmental stability in patients suffering from lumbar intra spinal cysts (LISCs) and to determine the outcome of microscopic unilateral laminotomy and cystectomy. METHODS: All patients that were surgically managed for a LISC between 2007 and 2013 with more than 3 years of follow-up were reviewed. Those without associated instability were evaluated for segmental mobility, segmental angulation, facet inclination, stage of disc degeneration, and level of involvement on MRI and dynamic radiographs. Outcomes of unilateral laminotomy and cystectomy were evaluated using VAS (Visual Analogue Score), ODI (Oswestry Disability Index), and Macnabs criteria. Dynamic radiographs were performed in all cases pre- and postoperatively and at the last follow-up. RESULTS: Thirty patients were operated for a LISC between 2007 and 2013. The levels involved were L4-5(23), L3-4(4) and L5-S1(3). The mean facet angle was 42.6 (± 6.1) degrees. The stage of disc degeneration was scattered haphazardly across all the cases (Gr 2[17]; Gr 3[1]; Gr 4[8]; Gr 5[4]). VAS and ODI scores improved significantly in all patients. Mean follow-up was 46.5 months (36-96 months). No patient developed postoperative instability at the last follow-up. CONCLUSIONS: The coronal inclination of the facet joints, absence of radiological instability, and poor co-relation with stages of disc degeneration suggests the presence of adequate residual stability. In this study, stand-alone decompression for LISCs without instability had well sustained good/excellent outcomes. Fusion is recommended for LISCs with associated instability.

Associated lumbar scoliosis does not affect outcomes in patients undergoing focal minimally invasive surgery-transforaminal lumbar interbody fusion (MISTLIF) for neurogenic symptoms-a minimum 2-year follow-up study.

BACKGROUND CONTEXT: There is no current literature comparing outcomes of patients with and without lumbar scoliosis having neurologic symptoms undergoing minimally invasive surgery-transforaminal lumbar interbody fusion (MISTLIF) technique. PURPOSE: This study aimed to determine whether associated lumbar scoliosis will result in different clinical, radiological, and operative outcomes in patients undergoing focal MISTLIF for neurogenic symptoms, without specific correction of the scoliosis. STUDY DESIGN: A retrospective case comparison study from prospectively collected hospital registry data was carried out. PATIENT SAMPLE: Two hundred and thirty eligible patients were evaluated and divided into two groups: Scoliosis Group (SG; n=57) with Cobb angle >10 degrees on anterioposterior (AP) plain lumbar spine radiographs and Non-Scoliosis Group (NSG; n=173) consisting of the remaining patients. OUTCOME MEASURES: Clinical outcomes were assessed using the Oswestry Disability Index, the North American Spine Society (NASS) Neurogenic Symptom Score, the NASS Satisfaction with Surgery Rating, the 36-Item Short-Form Health Survey (SF-36), and the Numerical Pain Rating Scale for back and leg pain. Radiological findings included Cobb angle, fusion, implant failure or loosening, and adjacent segment degeneration (ASD). METHODS: Both groups were compared for demographics, perioperative parameters, complications, clinical, and radiological outcomes. Interobserver agreement (kappa statistics) for measurement of Cobb angle was calculated on all cases of both groups by two authors. Patients were evaluated preoperatively, at 6 months, and 2 years after surgery. RESULTS: The average follow-up was 2.88±1.47 years in the SG and 2.71±1.34 years in the NSG (p=.444). Differences in mean age (SG: 62.9±10.9 years and NSG: 57.6±13.1 years), estimated related risk of death (SG: 3.05±2.13 and NSG: 2.41±1.74), and gender (female=SG: 87.7% and NSG: 64.2%) were statistically significant (p<.05), whereas race distribution, body mass index |(BMI), spinal levels operated, number of levels operated, bone morphogenetic protein (BMP)-2 use, and type of bone graft were not. Fluoroscopic time, operative time, blood loss, postoperative opioid usage, time to ambulation, and length of hospitalization were similar (p>.05). Preoperative and postoperative clinical outcomes were similar in both groups (p>.05) except SF-36 physical function score, which was found to be significantly higher in the NSG at final follow-up (p<.05). Clinical outcomes scores improved significantly postoperatively (p<.05), and grade 1 fusion (Bridwell classification) was achieved in 93% in the SG and in 93.6% in the NSG (p=.417). Total complications were 11 (19.29%) in the SG and 21 (12.13%) in the NSG (p=.097). De novo ASD was found in 1 case in the SG and in 14 cases in the NSG (p=.124), with 1 case in the NSG requiring further surgery. CONCLUSION: Associated mild lumbar scoliosis (Cobb angle <30°) does not result in significantly different perioperative, clinical, and radiological outcomes in patients undergoing focal decompression and MISTLIF for neurogenic symptoms.

Minimal invasive transforaminal lumbar interbody fusion versus open transforaminal lumbar interbody fusion.

BACKGROUND: The aim of the present prospective study is to evaluate whether the touted advantages of minimal invasive-transforaminal lumbar interbody fusion (MI-TLIF) translate into superior, equal, or inferior outcomes as compared to open-transforaminal lumbar interbody fusion (O-TLIF). This is the first study from the Indian subcontinent prospectively comparing the outcomes of MI-TLIF and O-TLIF. MATERIALS AND METHODS: All consecutive cases of open and MI-TLIF were prospectively followed up. Single-level TLIF procedures for spondylolytic and degenerative conditions (degenerative spondylolisthesis, central disc herniations) operated between January 2011 and January 2013 were included. The pre and postoperative Oswestry Disability Index (ODI) and visual analog scale (VAS) for back pain and leg pain, length of hospital stay, operative time, radiation exposure, quantitative C-reactive protein (QCRP), and blood loss were compared between the two groups. The parameters were statistically analyzed (using IBM® SPSS® Statistics version 17). RESULTS: 129 patients underwent TLIF procedure during the study period of which, 71 patients (46 MI-TLIF and 25 O-TLIF) fulfilled the inclusion criteria. Of these, a further 10 patients were excluded on account of insufficient data and/or no followup. The mean followup was 36.5 months (range 18-54 months). The duration of hospital stay (O-TLIF 5.84 days + 2.249, MI-TLIF 4.11 days + 1.8, P < 0.05) was shorter in MI-TLIF cases. There was less blood loss (open 358.8 ml, MI 111.81 ml, P < 0.05) in MI-TLIF cases. The operative time (O-TLIF 2.96 h + 0.57, MI-TLIF 3.40 h + 0.54, P < 0.05) was longer in MI group. On an average, 57.77 fluoroscopic exposures were required in MI-TLIF which was significantly higher than in O-TLIF (8.2). There was no statistically significant difference in the improvement in ODI and VAS scores in MI-TLIF and O-TLIF groups. The change in QCRP values preoperative and postoperative was significantly lower (P < 0.000) in MI-TLIF group than in O-TLIF group, indicating lesser tissue trauma. CONCLUSION: The results in MI TLIF are comparable with O-TLIF in terms of outcomes. The advantages of MI-TLIF are lesser blood loss, shorter hospital stay, lesser tissue trauma, and early mobilization. The challenges of MI-TLIF lie in the steep learning curve and significant radiation exposure. The ultimate success of TLIF lies in the execution of the procedure, and in this respect the ability to achieve similar results using a minimally invasive technique makes MI-TLIF an attractive alternative.

Intraoperative reduction does not result in better outcomes in low-grade lumbar spondylolisthesis with neurogenic symptoms after minimally invasive transforaminal lumbar interbody fusion-a 5-year follow-up study.

BACKGROUND CONTEXT: Intraoperative reduction of low-grade lumbar spondylolisthesis (LGLS) remains disputed. There is currently no published data comparing midterm outcomes of reduction versus in situ fusion. PURPOSE: This study aimed to compare mid-term clinical, radiological, and perioperative outcomes for reduction versus in situ fusion in LGLS with neurogenic symptoms. STUDY DESIGN/SETTING: A retrospective review of prospectively collected spine registry data in a single institution was carried out. PATIENT SAMPLE: All patients who underwent minimally invasive transforaminal lumbar interbody fusion (MIS TLIF) for LGLS with neurogenic symptoms with a minimum 5-year follow-up comprised the patient sample. OUTCOME MEASURES: Self-reported measures were Oswestry Disability Index, North American Spine Society Neurogenic Symptom Score, Health Outcomes Survey Short Form-36 score, and Numerical Pain Rating Scale (back and leg pain). Radiological outcomes were fusion grading, adjacent segment degeneration (ASD), and implant failure or loosening. Perioperative outcomes were fluoroscopic time, operative time, intraoperative blood loss, opioid analgesia usage, time to ambulation, duration of hospitalization, and complication rate. Functional outcomes were patient satisfaction rate and rate of return to full function. METHODS: A retrospective review was performed on prospectively collected registry data of patients undergoing MIS TLIF for LGLS with neurogenic symptoms, from 2004 to 2009. The operative technique and postoperative protocol were standardized. Two groups were formed based on complete reduction of the spondylolisthesis (reduction group [RG]) or the lack thereof (non-reduction group [NRG]) in the immediate postoperative radiograph. Outcomes at baseline, 6 months, 2 years, and 5 years postsurgery were compared. RESULTS: There were 56 patients included (RG=30, NRG=26). The two groups had comparable baseline characteristics: demographics, body mass index, spondylolisthesis etiology, spinal level involved, bone graft and bone morphogenetic protein used, and all self-reported outcome measures. Perioperative outcomes were not significantly different. The early complication rate (RG=3.3%, NRG=19.2%, p=.086) and late complication rate (RG=10%, NRG=23.1%, p=.184) were similar. All patients achieved Bridwell grade 1 fusion from 2 years onward. Adjacent segment degeneration rate at 5 years was similar (RG=10%, NRG=0%, p=NS). Both groups showed significant postoperative improvement in all self-reported measures with no significant differences between the two groups at all follow-up points. Functional outcomes were equivalent. CONCLUSIONS: Intraoperative reduction does not improve outcomes in LGLS with neurogenic symptoms after MIS TLIF. Adequate decompression and solid fusion are likely the keys to good mid-term outcomes.

Posterior Cervicothoracic Instrumentation: Testing the Clinical Efficacy of Tapered Rods (Dual-Diameter Rods).

STUDY DESIGN: Prospective study. OBJECTIVE: To study the clinical efficacy of tapered rods in posterior cervicothoracic instrumentation. SUMMARY OF BACKGROUND DATA: The cervicothoracic spine is a junctional area with complex biomechanics. A variety of disorders affect this region, rendering it unstable. Numerous posterior constructs have been evaluated by in vitro biomechanical studies. There are no data available on the clinical efficacy of a screw-rod system utilizing tapered (dual-diameter) rods. This is the first study analyzing the efficacy of this system in clinical scenarios in the short term. MATERIALS AND METHODS: All consecutive patients with cervicothoracic junctional pathologies undergoing surgical treatment by posterior instrumentation utilizing tapered rods, between April 2007 and April 2012 were included in the study. The tapered rod tapers from a diameter of 5.5-3.5 mm to accommodate thoracic pedicle screws and lateral mass screws/pedicle screws of cervical spine, respectively. The cases were periodically followed up. Postoperative radiographs and computed tomography scans were analyzed. RESULTS: There were 14 cases, 11 males and 3 females. The etiology was tuberculosis in 7 cases, neoplasm in 5, and 1 each of trauma and deformity. Three patients required combined anterior and posterior surgeries and remaining 10 were managed by posterior-only procedures. The average follow-up was 28 months. Three patients died (surgically unrelated reasons) and 1 was lost to follow-up. Excluding 2 patients with neoplastic and traumatic etiologies, patients with neurological deficit had significant improvement. One patient had postoperative cerebrospinal fluid leak which was recognized and corrected subsequently. No biomechanical failure occurred in any of the patients. No intraoperative complications were noted. CONCLUSIONS: This study demonstrates that tapered rods are an excellent and a viable option to connect screws to stabilize cervicothoracic junction in the short term. This study complements the biomechanical studies previously reported.

Microendoscopic lumbar discectomy: Technique and results of 188 cases.

BACKGROUND: Discectomy performed open or with an operating microscope remains the standard surgical management. Tubular retractor system is being increasingly used. Potential benefits include less muscle and local damage, better cosmesis, decreased pain and operative time and faster recovery after surgery. We have evaluated the outcome of micro endoscopic discectomy (MED) utilizing tubular retractors in terms of safety and efficacy of the technique. MATERIALS AND METHODS: 188 consecutive patients who underwent surgery for herniated disc using the tubular retractors between April 2007 and April 2012 are reported. All patients had a preoperative MRI (Magnetic Resonance Imaging) and were operated by a single surgeon with the METRx system (Medtronic, Sofamor-Danek, Memphis, TN) using 18 and 16 mm ports. All patients were mobilized as soon as pain subsided and discharged within 24-48 hours post surgery. The results were evaluated by using VAS (Visual Analog Scale 0-5) for back and leg pain and ODI (Oswestry Disability Index). Patients were followed up at intervals of 1 week, 6 weeks, 3 months, 6 months, 12 months and 2 years. RESULTS: The mean age of patients was 46 years (range 16-78 years) and the sex ratio was 1.5 males to 1 female. The mean followup was 22 months (range 8-69 months). The mean VAS scale for leg pain improved from 4.14 to 0.76 (P < 0.05) and the mean VAS scale for back pain improved from 4.1 to 0.9 (P < 0.05). The mean ODI changed from 59.5 to 22.6 (P < 0.05). The mean operative time per level was about 50 minutes (range 20-90 minutes). Dural punctures occurred in 11 (5%) cases. Average blood loss was 30 ml (range 10-500 ml). A wrong level was identified and later corrected in a case of revision discectomy. Four patients with residual disc-herniation had revision MED and three patients with recurrent disc herniation later underwent fusion. One patient had wound infection which needed a debridement. CONCLUSION: MED for herniated discs effectively achieves the goals of surgery with minimal access. The advantages of the procedure are cosmesis, early postoperative recovery and minimal postoperative morbidity.

Microendoscopic excision of C2 osteoid osteoma: a technical report.

STUDY DESIGN: Case report and description of technique. OBJECTIVE: To describe a microendoscopic posterior approach for excision of an osteoid osteoma of C2. SUMMARY OF BACKGROUND DATA: Microendoscopic techniques are widely used in the management of degenerative disorders of the spine. This is the first report of their use in the management of an osteoid osteoma via the posterior approach. METHODS: A 12-year-old-boy presented with left-sided neck pain of 3-month duration. Investigations revealed an osteoid osteoma of C2 lamina-lateral mass complex. The patient underwent a posterior microendoscopic excision using 18-mm diameter METRx system (Medtronic Sofamor Danek, Memphis, TN) of tubular retractors. A postoperative computed tomographic scan was done and preoperative and postoperative visual analogue scale and Neck Disability Index were evaluated. The patient was periodically followed up for 1 year. RESULTS: The postoperative computed tomographic scan revealed complete excision of the tumor. The visual analogue scale score for neck pain improved from 3/5 (preoperative) to 0/5 (postoperative) and Neck Disability Index from 33.33 (preoperative) to 0 (postoperative) at 1-year follow-up. CONCLUSION: Microendoscopic techniques can be extended to excise lesions of the spine. It is a safe procedure in experienced hands. The advantages are minimal morbidity, minimal postoperative pain and discomfort, less analgesic dependence, and better cosmesis. The authors recommend this technique for accessible lesions involving the spine.

Should we cross the cross-links?

STUDY DESIGN: Retrospective study. OBJECTIVE: To assess critically if cross-links are necessary adjuvants in posterior spinal constructs. SUMMARY OF BACKGROUND DATA: Although numerous biomechanical studies are available in the literature, there has been no clinical study that has evaluated the need for cross-links in clinical situations. METHODS: The spinal constructs of patients of varied etiology who underwent surgery between July 2007 and July 2011 without the usage of cross-links were evaluated. The immediate postoperative erect radiographs were compared with the erect radiographs at the last follow-up by 2 independent observers (spine fellows not involved in the management of the patients) critically for any rotational instability using the Nash-Moe technique of assessment of vertebral rotation as well as for any "parallelogram effect." The intraobserver and interobserver reliability was analyzed. RESULTS: There were 208 cases included in the study during the study period that satisfied the criteria. The total number of motion segments fused was 707 ranging from 1 to 15 involving various etiologies. The average follow-up was 15 months (12-36 mo). Barring one patient with a thoracolumbar fracture with rotational instability (AO [Arbeitsgemeinschaft für Osteosynthesefragen] type C) who had undergone a short-segment fixation, none of the cases demonstrated any rotational instability in the follow-up radiographs. Interestingly, the rotational instability (parallelogram effect) in that patient got corrected spontaneously once anterior reconstruction was performed. The intraobserver reliability was 100% and the interobserver reliability was 92.83%. This variability was in assessing the grade of vertebral rotation only; none of the levels had a change in rotation irrespective of variation in grade assessment in the final postoperative radiograph. CONCLUSION: This study concludes that use of cross-links in clinical practice may be avoidable. The derivations from biomechanical studies do not translate into clinical advantages. Eliminating the usage of cross-links reduces the operative time as well as the overall total hospital costs (a single cross-link may cost anywhere between $1500 and $2000 and surgeons tend to use single or multiple cross-links). Additionally, prominence of implants, corrosion, infection, implant failure, and pseudarthrosis are the other complications attributed to cross-links in the literature that can be eliminated by preventing their incorporation in spinal constructs. LEVEL OF EVIDENCE: N/A.