Type I Arnold Chiari Malformation with Syringomyelia and Scoliosis: Radiological Correlations between Tonsillar Descent, Syrinx Morphology and Curve Characteristics: A Retrospective Study.

STUDY DESIGN: Retrospective cohort. PURPOSE: The current study was planned to evaluate deformity characteristics, assess relationship between morphology of syrinx/Arnold Chiari malformation (ACM) and deformity, analyze effect of posterior fossa decompression (PFD), and evaluate outcome. OVERVIEW OF LITERATURE: Scoliosis in ACM-I and syringomyelia (SM) is uncommon, and deformity characteristics differ from those seen in idiopathic scoliosis. METHODS: Data regarding patients, who underwent PFD for ACM-I presenting with SM and scoliosis between January 2009 and December 2018, were retrospectively collected. Only patients with 2-year follow-up were included. Sagittal/coronal deformity and sagittal spinopelvic parameters were examined. Symmetry and extent of tonsillar descent, as well as morphology (configuration/variation) and extent of syrinx were determined. RESULTS: A total of 42 patients (20 females; age: 14.2±5.8 years) were included; 35 patients (83.3%) had atypical curves. Mean preoperative coronal Cobb was 57.7°±20.9°; and 12 (28.6%) had significant coronal imbalance. Tonsillar descent was classified as grade 1, 2, and 3 in 16 (38.1%), 11 (26.2%), and 15 (35.7%) patients; 35 patients (83.3%) had asymmetric tonsillar descent; 17 (40.4%), 3 (7.1%), 16 (38.1%), and 6 (14.4%) had circumscribed, moniliform, dilated, and slender syrinx patterns; and 9 (21.4%), 12 (28.6%), and 21 (50%) of syrinx were right-sided, left-sided, and centric. There was no significant relationship between side of tonsillar dominance (p =0.31), grade of descent (p =0.30), and convexity of deformity. There was significant association between side of syrinx and convexity of scoliosis (p =0.01). PFD was performed in all, and deformity correction was performed in 23 patients. In curves ≤40°, PFD alone could stabilize scoliosis progression (p =0.02). There was significant reduction in syrinx/cord ratio following PFD (p <0.001). CONCLUSIONS: ACM-I+SM patients had atypical curve patterns in 83% of cases, and the side of syrinx deviation correlates with scoliosis convexity. Syrinx shrinks significantly following PFD. PFD may not stabilize scoliosis in curves >40°.

Role of Whole-Body Computed Tomography Scan to Avoid Missed Foreign Body in Patients with Multiple Stab Injury: A Rare Case of Retained Impaled Knife Blade with Intact Neurology.

Nonmissile penetrating spine injury (NMPSI) is usually encountered in young men, secondary to knife-inflicted injuries. Such injuries often present with complete or incomplete neurodeficit. We hereby report a case of NMPSI (due to impaled knife blade) in the cervical spine, who presented with intact neurology. She was managed by foreign body removal, dural repair, and cerebrospinal fluid (CSF) diversion with lumbar drain. We performed postoperative magnetic resonance imaging with diffusion tensor imaging and tractography to ascertain the cord status. The case highlights the importance of whole-body computed tomography in patients with multiple stab wounds and the use of CSF diversion in such situations.

Advanced disc degeneration, bi-planar instability and pathways of peri-discal gas suffusion contribute to pathogenesis of intradiscal vacuum phenomenon.

PURPOSE: Intradiscal vacuum phenomenon (IDVP), despite being ubiquitous, is poorly understood. The dynamic passage of peri-discal gases into the degenerated disc is a commonly accepted theory. But the reasons behind its selective appearance in some discs are unevaluated. METHODS: 721 patients with chronic low back pain ± radiculopathy, were evaluated with AP and flexion-extension lateral radiographs and MRI. IDVP was classified based on its morphology and location. Radiographic parameters including sagittal translation, sagittal angulation, lateral listhesis, eccentric disc collapse, Pfirrmann's grade, disc height, Modic changes, anterior longitudinal ligament status, and primary spinal disease at the level of IDVP was analyzed. RESULTS: IDVP was present in 342 patients, and they had a higher mean age (57.2 ± 12.5 years) than controls (p < 0.001). Eccentric disc space narrowing (26.5% vs 1.3%, p < 0.01), coronal listhesis (7.83% vs 1.1%, p < 0.001), sagittal angular motion difference (11.3 ± 4.6°, p < 0.001), higher mean disc degeneration (4.36 ± 0.69, p < 0.001), ALL disruption (30.3% vs 2.2%, p < 0.001) and Modic changes (88.6% vs 17.5%, p < 0.001) were significantly higher in IDVP discs (vs. non-IDVP). Binary logistic regression analysis indicated sagittal angular motion difference was the most predictive factor. IDVP was classified into three types-dense type (47.5%), linear (29.5%), dot type (23%). Dense type matched radiological correlations of IDVP while dot types behaved like non-IDVP discs. CONCLUSION: Modic disc-endplate contacts, ALL disruption and coronal translation could be pathways for the passage of peri-discal gases into the degenerated disc. In the pathogenesis of IDVP, advanced disc degeneration, the presence of pathways of gas transfer and angular/coronal instability seem to play complementary roles.

The analysis of progression of disc degeneration in distal unfused segments and evaluation of long-term functional outcome in adolescent idiopathic scoliosis patients undergoing long-segment instrumented fusion.

PURPOSE: To analyse the progression of disc degeneration in distal unfused lumbar segments in post-operative Adolescent Idiopathic Scoliosis (AIS) patients; and to evaluate pre-operative and post-operative radiological parameters associated with progressive disc degeneration. METHODS: A retrospective study of patients, who underwent surgery for AIS between 2006 and 2013 at a tertiary-care spine hospital, was conducted. Only patients aged between 11 and 18 years, who underwent deformity correction surgery with pedicle screw-only constructs, minimum of 6.5 year follow-up, and complete radiological data, and were included. On plain radiographs, coronal cobb's angle (CCA), apical translation, lower instrumented vertebra tilt (LIV tilt), LIV-Sacral angle, and sagittal spinal and pelvic parameters were measured. Disc degeneration was assessed on Magnetic Resonance Imaging (MRI) using Pfirrmann's grading. Total endplate score (TEPS) and facet degeneration (by Fujiwara's grading) were also measured. Based on the difference in progression of disc degeneration, patients were classified as Pfirrmann's grade static (PGS) and Pfirrmann's grade progressive (PGP) groups. Comparison of all pre- and post-operative parameters was made between PGS and PGP groups, and statistically analyzed. Functional evaluation was performed using SRS-22 score. RESULTS: A total of 58 patients were finally included. The mean follow-up was 9.1 years. 43 (74.1%) and 15 (25.9%) patients were classified under PGS and PGP groups, respectively. Among the15 patients in PGP group, selected LIV was L4 in 8, L3 in 3, L1 in 3, and L2 in 1. Among them, 11 patients (73.3%) progressed from grade 1 to grade 2. In the remaining 4 (26.6%), Pfirrmann's grade progressed to ≥ 3. The progression of disc degeneration did not correlate with age or sex distribution (p = 0.3), pre-operative and post-operative TEP scores (p = 032), pre-operative disc or facet degeneration (p = 0.52), number of unfused spinal segments (p = 0.56), pre-operative or post-operative coronal (p = 0.42), or sagittal spinal (p = 0.27) or pelvic parameters (p = 0.14). The final functional outcome (SRS-22) was not significantly different between PGS and PGP groups (p = 0.67). CONCLUSION: 74% of AIS patients demonstrated no signs of progressive disc degeneration at an average follow-up of 9.1 years. 26% (15/58) of AIS patients demonstrated progressive disc degeneration, among whom, degeneration progressed by only 1 Pfirrmann's grade in 74% (11/15). In the remaining four patients, disc degeneration progressed to Pfirrmann's grades 3 or greater. There was no correlation between higher grades of disc degeneration and lower instrumented vertebra (LIV) or functional outcomes scores (SRS-22).

Missed Intracranial Subdural Hematoma in a Case of Spontaneous Subdural Spinal Hematoma: A Rare Case Report and Literature Review.

INTRODUCTION: Idiopathic spontaneous spinal subdural hematoma (ISSSDH) is uncommon in occurrence, and its association with concomitant intracranial subdural hematoma (ISDH) is very exceptional. Lack of recognition of ISDH in a patient with SSDH can lead to unanticipated events. We report a rare case of ISSSDH and unrecognized ISDH and treated surgically with a good outcome. CASE REPORT: A 71-year-old gentleman presented with features of spinal neurogenic claudication of 2 weeks duration and was diagnosed to have ISSSDH of the lumbar spine based on magnetic resonance imaging (MRI). In view of an impending cauda equina syndrome, he underwent an emergency decompression through a laminectomy, durotomy, and clot evacuation from L2 to L5. The next day, he developed sudden-onset hemiparesis and altered sensorium. The computed tomography (CT) scan of the brain demonstrated an ISDH, for which emergency burr hole evacuation was done.The patient improved rapidly after the surgery and regained his normal power, sensorium, and achieved comfortable ambulation within a week. Follow-up CT of the brain and MRI scan of the spine revealed adequate decompression. Since the CT features of ISDH were of acute on chronic nature, we presume that it had existed before the onset of spinal symptoms. CONCLUSION: Through this very rare case, we highlight the importance of screening the brain pre-operatively in patients who present with sub-acute spontaneous spinal SDH.