Risk factors for thirty-day morbidity and mortality after spinal trauma.

BACKGROUND: Traumatic Spinal Injuries (TSI) often follow high velocity injuries and frequently accompanied by polytrauma. While most studies have focussed on outcomes of spinal cord injuries, the incidence and risk factors that predict morbidity and mortality after TSI has not been well-defined. METHODS: Data of consecutive patients of TSI (n = 2065) treated over a 5-year-period were evaluated for demographics, injury mechanisms, neurological status, associated injuries, timing of surgery and co-morbidities. The thirty-day incidence and risk factors for complications, length of stay and mortality were analysed. RESULTS: The incidence of spinal trauma was 6.2%. Associated injuries were seen in 49.7% (n = 1028), and 33.5% (n = 692) patients had comorbidities. The 30-day mortality was 0.73% (n = 15). Associated chest injuries (p = 0.0001), cervical spine injury (p = 0.0001), ASIA-A neurology (p < 0.01) and ankylosing spondylitis (p = 0.01) correlated with higher mortality. Peri-operative morbidity was noted in 571 patients (27.7%) and were significantly associated with age > 60 (p = 0.043), ASIA-A neurology (p < 0.05), chest injuries (p = 0.042), cervical and thoracic spine injury (p < 0.0001). The mean length of stay in hospital was 8.87 days. Cervical spine injury (p < 0.0001), delay in surgery > 48 h (p = 0.011), Diabetes mellitus (p = 0.01), Ankylosing spondylitis (p = 0.009), associated injuries of chest, head, pelvis and face (p < 0.05) were independent risk factors for longer hospital stay. CONCLUSION: Key predictors of mortality after spinal trauma were cervical spine injury, complete neurological deficit, chest injuries and ankylosing spondylitis, while additionally higher age and thoracic injuries contributed to higher morbidity and prolonged hospitalisation. Notably multi-level injuries, higher age, co-morbidities and timing of surgery did not influence the mortality.

ISSLS PRIZE in basic science 2023: Lactate in lumbar discs-metabolic waste or energy biofuel? Insights from in vivo MRS and T2r analysis following exercise and nimodipine in healthy volunteers.

PURPOSE: To quantitatively assess the dynamic changes of Lactate in lumbar discs under different physiological conditions using MRS and T2r. METHODS: In step1, MRS and T2r sequences were standardized in 10 volunteers. Step2, analysed effects of high cellular demand. 66 discs of 20 volunteers with no back pain were evaluated pre-exercise (EX-0), immediately after targeted short-time low back exercises (EX-1) and 60 min after (EX-2). In Step 3, to study effects of high glucose and oxygen concentration, 50 lumbar discs in 10 volunteers were analysed before (D0) and after 10 days intake of the calcium channel blocker, nimodipine (D1). RESULTS: Lactate showed a distinctly different response to exercise in that Grade 1 discs with a significant decrease in EX-1 and a trend for normalization in Ex-2. In contrast, Pfirrmann grade 2 and 3 and discs above 40 years showed a higher lactate relative to proteoglycan in EX-0, an increase in lactate EX-1 and mild dip in Ex-2. Similarly, following nimodipine, grade 1 discs showed an increase in lactate which was absent in grade 2 and 3 discs. In contrast, exercise and Nimodipine had no significant change in T2r values and MRS spectrum of proteoglycan, N-acetyl aspartate, carbohydrate, choline, creatine, and glutathione across age groups and Pfirrmann grades. CONCLUSION: MRS documented changes in lactate response to cellular demand which suggested a 'Lactate Symbiotic metabolic Pathway'. The differences in lactate response preceded changes in Proteoglycan/hydration and thus could be a dynamic radiological biomarker of early degeneration.

Accelerated anterior vertebral growth resulting in kyphosis correction following posterior spinal instrumented fusion.

PURPOSE: To discuss the effect of posterior instrumented deformity correction and fusion on the progressive endochondral ossification of anterior vertebral body in a patient with congenital kyphosis secondary to type 1 vertebral anomaly. METHODS: A 15-year-old male patient presented with a progressively worsening congenital TL kyphosis of 52° magnitude secondary to a posterior hemivertebra. His pre-operative antero-posterior vertebral height ratio (APVHR) and anterior vertebral body defect ratio (AVBDR) on CT were 38% and 49%, respectively. He underwent posterior instrumented deformity correction with multilevel type 1 Schwab osteotomies and fusion. RESULTS: Over the next 3 years, his serial imaging revealed progressive endochondral ossification and gradual increase in the dimensions of the vertebral body. At the final follow-up, there was a significant restoration of the deficient anterior vertebral body, and the final APVHR and AVBDR were 81% and 90%, respectively. CONCLUSIONS: Restitution of posterior column integrity through stabilization can mitigate the compressive stresses across anterior column. Over a period of time, forces restraining the growth of anterior vertebral apophysis are alleviated, and the vertebra can potentially re-grow to near-normal dimensions in pediatric population. This phenomenon could be well-demonstrated in our patient during follow-up. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

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.

Transient paraplegia in lumbar spine surgery-a potential complication following erector spinae plane block.

PURPOSE: Erector spinae plane block (ESPB) has gained popularity over recent years and is being increasingly used in spine surgery for pain management. To date, no major neurological complications have been reported. We present here two patients who developed transient postoperative paraplegia and discuss the possible causes of this phenomenon. METHODS: Patients, who underwent preoperative bilateral ESPB as an adjunct to general anesthesia for elective lumbar spine surgery at our institution between January 2017 and December 2020, were retrospectively identified. Among them, only patients who developed postoperative motor and sensory deficits were finally included. RESULTS: Overall, two patients [of 316 who underwent ESPB (0.6%)] developed complete motor and sensory deficits in bilateral lower limbs postoperatively. In both patients, the surgery was uncomplicated. Ninety minutes following recovery from general anesthesia, both patients showed gradual neurological recovery in a distal-to-proximal pattern, with complete motor recovery preceding the sensory improvement. Since the surgical procedure was performed at the cauda equine level, transient paraplegia in these patients could only attributed to ESPB. CONCLUSION: Transient paraplegia following ESPB (due to anterior spread of the local anesthetic agent into the epidural space) has never been reported, and both anesthetists and surgeons must be aware of this possible complication.

The phenomenon of vertebral body drift in neurofibromatosis and its implications for surgical safety.

OBJECTIVE: To report on the phenomenon of body drift in neurofibromatosis scoliosis and discuss its implication on surgical safety. MATERIALS AND METHODS: Ten dystrophic neurofibromatosis scoliosis (NF) and ten adolescent idiopathic scoliosis (AIS) were studied by radiographs, CT, and MRI. The curve characteristics and a detailed analysis of the morphology of the apical and three adjacent vertebral segments above and below were done. The coronal alignment and the presence of a drift of the vertebral body in relationship to the lamina were carefully studied in both groups and compared. RESULTS: The mean cobb angle in the NF group was 77.6°, and 63.7° in the AIS group. All the studied vertebra in the NF group had extensive pedicle changes, which were more severe at the apical and periapical regions. Body drift was noted in 29 vertebral segments, with 9/10 of apical segments showing a significant drift. The body drift was associated with significant pedicle dystrophic changes and was independent of the curve magnitude. In comparison, in AIS, no body drift was noted despite a larger deformity and more severe vertebral rotation. CONCLUSION: The 'body drift' phenomenon was unique to neurofibromatosis scoliosis and was secondary to severe pedicle morphology changes. This was present even in curves less than 60° and could result in cord injury while instrumenting the concave pedicle. Therefore, a thorough preoperative assessment and planning by a 3D CT are mandatory.

Are Modic changes 'Primary infective endplatitis'?-insights from multimodal imaging of non-specific low back pain patients and development of a radiological 'Endplate infection probability score'.

PURPOSE: To probe the pathophysiological basis of Modic change (MC) by multimodal imaging rather than by MRI alone. METHODS: Nineteen radiological signs found in mild infections and traumatic endplate fractures were identified by MRI and CT, and by elimination, three signs unique to infection and trauma were distilled. By ranking the Z score, radiological 'Endplate Infection Probability Score' (EIPS) was developed. The score's ability to differentiate infection and traumatic endplate changes (EPC) was validated in a fresh set of 15 patients each, with documented infection and trauma. The EIPS, ESR, CRP, and Numeric Pain Rating Scale (NRS) were then compared between 115 patients with and 80 patients without MC. RESULTS: The EIPS had a confidence of 66.4%, 83% and, 100% for scores of 4, 5 and, 6, respectively, for end plate changes suggesting infection. The mean EIPS was 4.85 ± 1.94 in patients with Modic changes compared to - 0.66 ± 0.49 in patients without Modic changes (p < 0.001). Seventy-eight (67.64%) patients with MC had a score of 6, indicating high infection possibility. There was a difference in the NRS (p < 0.01), ESR (p = 0.05), CRP (p < 0.01), and type of pain (p < 0.01) between patients with and without MC. CONCLUSION: Multimodal imaging showed many radiological signs not easily seen in MRI alone and thus missed in Modic classification. There were distinct radiological differences between EPCs of trauma and infection which allowed the development of an EIPS. The scores showed that 67.64% of our study patients with Modic changes had EPCs resembling infection rather than trauma suggesting the possibility of an infective aetiology and allowing us to propose an alternate theory of 'Primary Endplatitis'.

Influence of endplate avulsion and Modic changes on the inflammation profile of herniated discs: a proteomic and bioinformatic approach.

PURPOSE: The aim of this observational radiographic and proteomic study is to explore the influence of both Modic change (MC) and endplate avulsion (EPA) on the inflammation profile of herniated discs using a proteomic and bioinformatics approach. METHODS: Fifteen nucleus pulposus (NP) harvested from surgery underwent LC-MS/MC analysis, the proteome was subsequently scanned for inflammatory pathways using a bioinformatics approach. All proteins that were identified in inflammatory pathways and Gene Ontology and present in > 7 samples were integrated in a multiple regression analysis with MC and EPA as predictors. Significant proteins were imputed in an interaction and pathway analysis. RESULTS: Compared to annulus fibrosus tear (AFT), six proteins were significantly altered in EPA: catalase, Fibrinogen beta chain, protein disulfide-isomerase, pigment epithelium-derived factor, osteoprotegerin and lower expression of antithrombin-III, all of which corresponded to an upregulation of pathways involved in coagulation and detoxification of reactive oxygen species (ROS). Moreover, the presence of MC resulted in a significant alteration of nine proteins compared to patients without MC. Patients with MC showed a significantly higher expression of clusterin and lumican, and lower expression of catalase, complement factor B, Fibrinogen beta chain, protein disulfide-isomerase, periostin, Alpha-1-antitrypsin and pigment epithelium-derived factor. Together these altered protein expressions resulted in a downregulation of pathways involved in detoxification of ROS, complement system and immune system. Results were verified by Immunohistochemistry with CD68 cell counts. CONCLUSION: Both EPA and MC status significantly influence disc inflammation. The beneficial inflammatory signature of EPA illustrates that endplate pathology does not necessarily have to worsen the outcome, but the pathological inflammatory state is dependent on the presence of MC.

Posterior-only stabilization versus global reconstruction in thoracic and thoracolumbar spinal tuberculosis; a prospective randomized study.

PURPOSE: Although the guidelines for surgical indications in spinal tuberculosis (TB) are well-established, ambiguity still exists in deciding between posterior-only stabilization and global reconstruction in thoracic and thoracolumbar (TL) disease especially in patients with borderline vertebral destruction. The current prospective, randomized study was thus planned to compare safety and efficacy of these two surgical interventions. METHODS: Patients, aged between 18 and 65 years, with spinal TB involving thoracic and TL spine with pre-operative vertebral body loss (VBL) between 0.5 and 1 were randomly allocated into two groups [groups A (who underwent posterior-only stabilization) and B (global reconstruction through a single-stage all-posterior approach). Patient's demographic data, clinical, intra-operative and post-operative details were recorded. Minimum follow-up period was two years. Neurological assessment was performed using ASIA impairment scale. Functional outcome measurements included VAS and ODI scores (pre-operative and final follow-up). Radiological measurements included Cobb's angle, kyphosis correction, loss of correction, angle loss rate and fusion time. RESULTS: Fifty-eight patients (groups A and B = 29 each) were included. Mean age in groups A and B was 48.3 ± 16.5 years and 51.2 ± 11.7 years. Mean surgical duration was significantly shorter in group A (119.9 ± 14.1 minutes; p = 0.0001). Mean follow-up duration was 35.5 ± 6.4 months. There was no statistically significant difference in neurological outcome at final follow-up between the groups (p > 0.05). Group A demonstrated significantly better ODI at final follow-up (13.8 ± 2.9 vs 16.2 ± 4.1; p = 0.02). Immediate post-operative correction (6.8° ± 5.6) and maintenance of kyphosis correction at final follow-up [loss of correction (2.1° ± 1.7) and angle loss rate (16.3 ± 14.9%)] were marginally better in group B (p > 0.05). Mean fusion time in groups A and B was 7.8 ± 1.5 and 8.4 ± 1.6 months (p > 0.05). A sub-group analysis in group B between autograft and metallic cages for anterior reconstruction did not show significant difference in radiological outcome (p > 0.05). CONCLUSION: All-posterior surgeries (posterior-only stabilization or global reconstruction) represent an effective approach in the management of TB disease affecting thoracic and TL vertebrae. For a pre-operative VBL between 0.5 and 1, clinical (including neurological), functional and radiological outcomes following both these surgeries (posterior-only stabilization and global reconstruction) are comparable.

Is fresh, leucodepleted, whole blood transfusion superior to blood component transfusion in pediatric patients undergoing spinal deformity surgeries? A prospective, randomized study analyzing postoperative serological parameters and clinical recovery.

PURPOSE: To compare the effectiveness of fresh whole blood (FWB) and blood component transfusion in improving clinical outcome and serological parameters in the early postoperative period following spinal deformity surgery. METHODS: Patients undergoing major spinal deformity surgeries involving ≥ 6 levels of fusion and expected blood loss ≥ 750 ml between September 2017 and August 2018 were included in the study. The patients were randomized into two groups: FWBG and CG, receiving fresh whole blood and component transfusions, respectively. RESULTS: A total of 65 patients with spinal deformities of different etiologies were included. The mean age was 14.0 and 14.9 years in FWB and CG, respectively. All other preoperative parameters were comparable. The mean fusion levels and surgical time were 11.1 and 221.20 min in FWB, as compared with 10.70 and 208.74minutes in CG, respectively. Intraoperative blood losses were 929 ml (FWBG) and 847 ml(CG), and the mean volumes of transfusion were 1.90 (FWBG) and 1.65 units (CG). FWBG was significantly superior to CG in the following clinical and laboratory parameters: duration of oxygen dependence [36.43 (FWBG) vs. 43.45 h (CG); P = 0.0256], mean arterial pH [7.442 (FWBG) vs. 7.394 (CG); p < 0.001], interleukin-6 [30.04 (FWBG) vs. 35.10 (CG); p < 0.019], mean duration of HDU stay [40.6 hours (FWBG) vs 46.51 hours (CG); p = 0.0234] and postoperative facial puffiness [7/30 in FWBG vs. 18/35 (CG) (P < 0.02)]. CONCLUSION: FWB transfusion can potentially improve the immediate postoperative outcome in patients undergoing major spinal deformity surgeries by reducing the duration of intensive care unit stay and oxygen dependence. The other potential benefits of this practice, based on our study, include a reduced inflammatory response (reduced lactate and IL-6) and postoperative facial puffiness. However, further large-scale validation studies in future are necessary to precisely determine the role of FWB in spine surgeries. LEVEL OF EVIDENCE II: Diagnostic: individual cross-sectional studies with the consistently applied reference standard and blinding.

Presence of preoperative Modic changes and severity of endplate damage score are independent risk factors for developing postoperative surgical site infection: a retrospective case-control study of 1124 patients.

PURPOSE: There is increasing evidence of an association between Modic changes (MC) and subclinical infection. However, the association of MC with postoperative surgical site infection (SSI) has not been adequately probed. This study primarily aimed to investigate a probable association between preoperative MC, total endplate damage score (TEPS), and SSI. METHODS: A retrospective analysis of 1124 patients who underwent surgery in a single institution (2016-2018) was performed, using both univariate and multiple logistic regression analyses to identify independent risk factors for SSI. RESULTS: The prevalence of SSI was 4% (44/1124 patients), with no association with age or sex. The prevalence of MC in the SSI group was significantly higher-79.54% (35/44) compared to 58.79% (635/1080) (p value = 0.006) in the control group with no specific relation to type or location of MC. A higher TEPS was associated with SSI (p value = 0.009). A receiver operating characteristic (ROC) curve for TEPS values to assess predictiveness of SSI showed TEPS ≥ 5.5 to have a better sensitivity of 84% than 72% for a TEPS ≥ 6.5. Univariate analysis showed TEPS > 6 (odds ratio 3.887) to have a stronger association with SSI than the presence of MC (odds ratio 2.725). Among various types of surgeries, discectomy had a higher association with SSI (p value = 0.03) when compared to fusion (p value = 0.071). However, multiple logistic regression analysis revealed only TEPS > 6, presence of MC and hypothyroidism as independent risk factors for SSI. CONCLUSION: Our data suggest that preoperative MC and TEPS > 6 are independent risk factors for developing surgical site infections. MC could be foci of chronic subclinical infection and not mere markers of degeneration, as initially described.

Delayed presentation of urinoma mimicking spondylodiscitis secondary to ureteric injury following carrot stick fracture in ankylosing spondylitis.

INTRODUCTION: Ureteric injuries are rarely associated with spinal trauma with an incidence of less than 1%. Missed injuries can lead to urinoma collection, urosepsis and even death. MATERIALS AND METHODS: A 75-year-old man presented 1 month following fall with high-grade fever and severe back pain mimicking spondylodiscitis clinically. Plain radiograph showed features of ankylosing spondylitis with a suspicious trans-discal injury at L3-L4. Hyper-intense fluid within L3/L4 disk space communicating to a large psoas collection measuring 13 × 6 cms mimicking spondylodiscitis with abscess formation was observed in magnetic resonance imaging (MRI). MRI with contrast enhancement demonstrated a leak through left ureter into the psoas muscle raising suspicion of a ureteric injury. Plain computerized tomography revealed a three-column fracture at L4, and a ureteric leak into the psoas collection with proximal hydronephrosis was seen after contrast administration, establishing the presence of a ureteric fistula resulting in urinoma. RESULTS: Following initial symptomatic improvement after ureteric stenting, the patient succumbed to urosepsis at 3 months. CONCLUSION: We report for the first time a post-traumatic urinoma secondary to ureteric injury clinically mimicking spondylodiscitis. Clinicians need to be aware of the possibility of ureteric injury in hyperextension lumbar fractures occurring in ankylosing spondylitis and treat them early to avoid urological complications.

Unplanned return to operation room (OR) following growing spinal constructs (GSCs) in early onset scoliosis (EOS)-a multi-centric study.

PURPOSE: To evaluate the incidence and risk factors associated with the unplanned return to OR in EOS. METHODS: Medical records of 51 patients of EOS operated at three different centres using various types of GSCs were evaluated for complications requiring unplanned surgeries. Data were analysed to find out rate of unplanned surgeries in relation to the aetiology, age and Cobb angle at index surgery, type of implant, cause of unplanned surgery, and management required. RESULTS: Out of 51 patients, three did not meet inclusion criteria. Forty-eight patients of EOS operated by GSCs with a mean age of 6.7 years (range 2-12 years) with an average follow-up of 67.3 months were studied. There were 30 congenital, 10 idiopathic, 4 syndromic, and 4 neuromuscular cases. Thirty-nine out of 48 patients had one or more unplanned surgeries on follow-up (81.25%). Out of total 248 surgeries following index procedure, 82 were unplanned surgeries (33.06%), including 53 implant revisions, 12 implant-removal, 14 debridement, and 2 flaps. The common complications were 24.14% rod/screw breakage, 42.53% anchor pull-out, 16.09% infections, 6.90% wound dehiscence, and 4.6% neuro deficits. Unplanned surgeries were significantly higher in syndromic (58.8%) and neuromuscular (52.9%) than congenital (27.2%) and idiopathic (37.8%) cases (p < 0.05). Age at index procedure < 5 years had higher unplanned surgeries than age > 5 years (2.5 and 1.23 per patient, respectively,  p < 0.05). Type of implant and initial Cobb angle did not significantly affect the rate of unplanned surgeries (p  > 0.05) CONCLUSION: GSCs in EOS require a frequent revisit to operation room which should be well understood by the surgeon and parents.

Bezold-Jarisch reflex causing bradycardia and hypotension in a case of severe dystrophic cervical kyphotic deformity: a case report and review of literature.

PURPOSE: A 17-year-old adolescent with neurofibromatosis and severe cervicothoracic deformity was identified to have thoracic inlet compression leading to bradycardia and hypotension, only during prone positioning, and we discuss its successful management. METHODS: Preoperative halo-gravity traction reduced the deformity from 126° to 91°. During prone positioning, sudden onset bradycardia was followed by asystole, which disappeared immediately on turning over to supine position. Surgery was called off after two additional failed attempts of prone positioning. RESULTS: A retrospective analysis of CT and MRI showed severe narrowing of the thoracic inlet. In this patient, the right thoracic inlet was severely narrow, and prone positioning caused a further dynamic compromise stimulating right vagal nerve. The right vagus supplies the sinoatrial node, which is the natural pacemaker of the heart, and its stimulation causes sympathetic inhibition. Bezold-Jarisch reflex is a cardio-inhibitory reflex occurring due to vagal stimulation resulting in sudden bradycardia, asystole, and hypotension. To facilitate prone positioning, the medial end of the clavicles, along with limited manubrium excision, was performed relieving the vagal compression. C2-T4 instrumented decompression followed by anterior reconstruction and cervical plating was performed. The postoperative period was uneventful, and the final deformity was 45°. CONCLUSION: Bezold-Jarisch Reflex as a result of narrow thoracic inlet caused by cervical kyphosis and compensatory hyperlordosis of the upper thoracic spine has never been reported. This case highlights the need to introspect into thoracic inlet morphology in severe cervicothoracic deformities. Thoracic inlet decompression is an efficient way of addressing this unique complication.

Prognostic utility of magnetic resonance imaging (MRI) in predicting neurological outcomes in patients with acute thoracolumbar spinal cord injury.

PURPOSE: Utility of MRI for predicting neurological outcomes in acute cervical spinal cord injury (SCI) is well established but its value in thoracolumbar (TL) SCI needs to be evaluated. METHODS: Seventy-six patients operated for acute TL spinal injuries between January 2014 and March 2016 were reviewed to obtain demographic details, neurology at admission and at the final follow-up. Patients were divided based on the neurology at presentation into group 1 (ASIA A), group 2 (ASIA B, C, D) and group 3 (normal neurology). Preoperative MRI and CT scans were evaluated to measure parameters like osseus canal compromise, spinal cord compression (SCC), spinal cord swelling, length of cord swelling (LOS), length of edema (LOE) and the presence of hemorrhage. The MRI parameters were compared between the groups for their predictive value of neurology on admission and at the final follow-up. RESULTS: Of the 38 patients in group 1, six patients recovered by 1 grade, nine patients recovered by 2 grades and there was no recovery in 23 (60.5%) patients. Among group 2 patients, nine (40.9%) out of 22 recovered to ASIA E neurology. On univariate analysis, SCC (P = 0.009), LOS (P = 0.021) and length of edema (P = 0.002) were associated with complete neurological deficit at presentation. However, on multivariate regression analysis only LOE was significant (P = 0.007) in predicting neurology at admission and at follow-up. CONCLUSION: Greater the rostrocaudal LOE, worse is the neurology at presentation, and it is associated with poor neurological recovery at follow-up. These slides can be retrieved under Electronic Supplementary Material.

Human intervertebral discs harbour a unique microbiome and dysbiosis determines health and disease.

BACKGROUND: To document the role of sub-clinical infections in disc disorders and investigate the existence of microbiome in intervertebral discs (IVD). METHODS: Genomic DNA from 24 lumbar IVDs [8-MRI normal discs (ND) from brain dead yet alive organ donors, 8-disc herniation (DH), 8-disc degeneration (DD)] was subjected to 16SrRNA sequencing for profiling the diversity of human disc microbiome in health and disease. The disc microbiome was further compared to established human gut and skin microbiomes. RESULTS: All healthy MRI normal discs from brain dead yet alive organ donors also had a rich bacterial presence. A total of 424 different species (355-ND, 346-DD, and 322-DH) were detected, with 42.75% OTUs being classified at kingdom level, 44% at the phylum level, 22.62% at genus level, and 5.5% at species level. Varying biodiversity and abundance between healthy and diseased discs were documented with protective bacteria being abundant in normal discs, and putative pathogens abundant in DD and DH. Propionibacterium acnes had a similar but lower abundance to other pathogens in all three groups ND (3.07%), DD (3.88%), DH (1.56%). Fifty-eight bacteria were common between gut and IVD microbiomes, 29 between skin and IVD microbiomes, and six common to gut/skin/IVD. CONCLUSION: Our study challenges the hitherto concept of sterility in healthy IVD and documented a microbiome even in MRI normal healthy discs. The varying abundance of bacteria between ND, DD, and DH documents 'dysbiosis' as a possible etiology of DD. Many known pathogens were identified in greater abundance than Propionibacterium acnes, and there was evidence for the presence of the gut/skin/spine microbiome axis.

Unilateral sacroiliitis: differentiating infective and inflammatory etiology by magnetic resonance imaging and tissue studies.

PURPOSE: Unilateral sacroiliitis (US) is an uncommon disease with varied etiology. The differentiation between infective and inflammatory causes for US based on MRI alone is often difficult. We studied the efficacy of MRI findings in comparison with tissue studies in the diagnosis of US. METHODS: A retrospective analysis of patients who presented with US and evaluated with MRI, biopsy for histopathology and tissue cultures was performed. Patients with bilateral sacroiliitis, traumatic and postpartum sacroiliitis were excluded. Based on defined MRI criteria, the patients were divided into two groups-infective (group A) and inflammation (group B). RESULTS: In total, 33 patients (mean age-33.4 ± 17.2 years) with MRI features of US had presented with unilateral gluteal pain (100%) and positive Patrick's test (91.9%). Based on the MRI features of severe subchondral marrow edema, widening of joint space, intra-articular abscess and periarticular muscle abscess, infective sacroiliitis (A) was diagnosed in 20/33 (60.6% cases). A total of 13/33 (39.3%) patients had features of inflammation (B), based on the following MRI criteria-subchondral sclerosis with minimal edema, erosions, maintained joint space without abscess/destruction. Tissue evidence of infection was positive in 13/20 (65%) patients in group A while it was negative in all group B patients. CONCLUSION: MRI had high sensitivity (71%) and 100% specificity in diagnosing inflammatory sacroiliitis while it had low specificity, but 100% sensitivity for diagnosing infective sacroiliitis. Hence, patients diagnosed as inflammatory sacroiliitis in MRI are unlikely to benefit from further tissue studies while percutaneous biopsy is recommended in patients diagnosed in MRI as infective sacroiliitis.

Aneurysmal bone cyst of C2 treated with novel anterior reconstruction and stabilization.

PURPOSE: Aneurysmal bone cysts (ABC) form 1 % of primary bone tumors. Reported incidence rates are no more than 1.4 to 1,00,000. ABC of spine frequently involves posterior elements and commonly affects the lumbar spine (45 %). We present a case of C2 ABC for the challenges it poses due to the rarity of the lesion, tedious to access location, dilemmas relating to the suitable approach for tumor resection and technically demanding stabilization and reconstruction strategy post resection. METHODS: Clinical data analysis was performed to discuss a method of novel anterior column reconstruction following resection of a C2 aneurysmal bone cyst in a 8 year old child with anterior and posterior elements being involved. RESULTS: An 8-year-old girl with an aneurysmal bone cyst of the C2 vertebra underwent staged surgery following pre-operative embolisation. First a posterior approach tumor excision with posterior instrumented fusion was performed. Following which, using a modified anterior retropharyngeal approach anterior tumor excision and fibular graft reconstruction between the C1 lateral mass and C2 body was performed. Complete tumor clearance and stable reconstruction was successfully achieved in our patient. Patient showed excellent clinical outcome with radiological fusion. CONCLUSIONS: Preoperative embolisation in the treatment of ABC has supplemental advantage by reducing blood loss. Modified anterior retropharyngeal approach allows satisfactory clearance for C1-2 lesion and fibular strut graft between the C1 lateral mass and C2 body can provide a stable graft placement with good chance of fusion. Instability and spinal deformity, whether preexisting or post-excision, should be corrected with reconstruction and stabilization to offer best chance of cure in such cases.

Reliability of Allen Ferguson classification versus subaxial injury classification and severity scale for subaxial cervical spine injuries: a psychometrics study.

STUDY DESIGN: A psychometrics study. OBJECTIVES: To determine intra and inter-observer reliability of Allen Ferguson system (AF) and sub-axial injury classification and severity scale (SLIC), two sub axial cervical spine injury (SACI) classification systems. SETTING: Online multi-national study METHODS: Clinico-radiological data of 34 random patients with traumatic SACI were distributed as power point presentations to 13 spine surgeons of the Spine Trauma Study Group of ISCoS from seven different institutions. They were advised to classify patients using AF and SLIC systems. A reference guide of the two systems had been mailed to them earlier. After 6 weeks, the same cases were re-presented to them in a different order for classification using both systems. Intra and inter-observer reliability scores were calculated and analysed with Fleiss Kappa coefficient (k value) for both the systems and Intraclass correlation coefficient(ICC) for the SLIC. RESULTS: Allen Ferguson system displayed a uniformly moderate inter and intra-observer reliability. SLIC showed slight to fair inter-observer reliability and fair to substantial intra-observer reliability. AF mechanistic types showed better inter-observer reliability than the SLIC morphological types. Within SLIC, the total SLIC had the least inter-observer agreement and the SLIC neurology had the highest intra-observer agreement. CONCLUSION: This first external reliability study shows a better reliability for AF as compared to SLIC system. Among the SLIC variables, the DLC status and the total SLIC had least agreement. Low-reliability highlights the need for improving the existing classification systems or coming out with newer ones that consider limitations of the existing ones.

Factors that influence neurological deficit and recovery in lumbar disc prolapse-a narrative review.

Neurodeficit due to lumbar disc herniation (LDH) is a serious complication and can range from sensory hypoesthesia in a single dermatome to a debilitating condition like cauda equina syndrome (CES). Many authors have described variable clinical and radiological risk factors for neurodeficit in LDH. Similarly the prognostic factors influencing recovery have been variable across the studies. This narrative review discusses the pathogenesis, most consistent factors associated with the occurrence of neurodeficit in LDH patients and also the factors which have a prognostic role in recovery. Pathological mechanisms like venous congestion, neuronal ischaemia and multiple root impairment act either individually or in combination to result in neurodeficit in LDH patients. Among the clinical risk factors, diabetes mellitus and acute onset of symptoms have been associated with neurodeficit while pre-existing spinal canal stenosis, non-contained discs (sequestrated/migrated) are potential radiological risk factors for developing neurodeficit. When considering prognostic factors for recovery, pre-operative muscle strength is the only significant factor. Knowledge about the causative and prognostic factors in neurodeficit following LDH would help in the successful management of this condition.