BACKGROUND:Adjacent-level disease after anterior cervical discectomy and fusion (ACDF) occurs in a significant proportion of patients and frequently requires revision operation. Methods using traditional plates typically require removal of the plate with anecdotally increased operative-time and morbidity. We review our experience in treating symptomatic adjacent-segment disease using both traditional plate removal and modular-plate system which allows for add-on plate components rather than removal of the entire plate.METHODS:Authors compared 64 patients with revision surgery using modular-plate system for adjacent-segment disease compared to 2-cohorts: 1) patients with traditional plate-removal; and 2) patients with no prior plate. Clinical data included demographics, original surgery, presentation, current surgery, use of modular system, need for preoperative computed-topography, operative-time, blood loss, hospital stay, complications, length of dysphagia, neck disability index and time-until-fusion.RESULTS:Modular cervical plate system was utilized to prevent exposure and removal of the entire plate. The terminal portion of the plate was exposed and the distal module was removed. Following the discectomy/arthrodesis, a module-plate extension was added onto the previous plate for extension of the prior instrumentation. Preoperative planning computed-topography was required in 26% of plate-removal and 17% of modular-plate cases. Revision surgery with no prior plate had reduced operative-time (77.0±18.1 min) when compared with plate removal (103.8±46.2 min; P<0.01). Blood-loss was lower for modular-plate system (38.3±20.4 mL) and no prior plate (38.4±12.6 mL) versus plate removal (78.2±65.9 mL, P<0.01). Hospital stay was similar for all groups. No complications were experienced with modular-plate revision but plate removal and revision after no prior plate carried 7.7% and 10.5% complication rates, respectively. There was a trend towards lower dysphagia and neck disability index with modular-plate revision.CONCLUSIONS:Use of modular cervical plate system allows for extension of a plate and reduces morbidity when treating adjacent-segment disease.

STUDY DESIGN:Retrospective cohort study.OBJECTIVE:To evaluate the performance and convergent validity of the disabilities of the arm, shoulder, and hand (DASH) in comparison with the visual analog scale (VAS) for pain, and neck disability index (NDI) in patients undergoing cervical spine surgery.SUMMARY OF BACKGROUND DATA:Neck-specific disability scales do not adequately assess concurrent upper extremity involvement in patients with cervical spine disorders. The DASH is a patient-reported outcomes (PRO) instrument designed to measure functional disability due to upper extremity conditions but has additionally been shown to perform well in patients with neck disorders.METHODS:We identified patients who underwent cervical spine surgery at our institution between 2013 and 2016. We collected demographic information, clinical characteristics, and PRO measures-DASH, VAS, NDI-preoperatively, as well as early and late postoperatively. We calculated descriptive statistics and changes from baseline in PROs. Correlation coefficients were used to quantify the association between PRO measures. The analysis was stratified by radiculopathy and myelopathy diagnoses.RESULTS:A total of 1046 patients (52.8% male) with PROs data at baseline were included in the analysis. The mean age at surgery ± SD was 57.2 ± 11.3 years, and postoperative follow-up duration 12.7 ± 10.7 months. The most common surgical procedure was anterior cervical discectomy and fusion (71.1%). Patients experienced clinically meaningful postoperative improvements in all PRO measures. The DASH showed moderate positive correlations with VAS preoperatively (Spearman rho = 0.43), as well as early (rho = 0.48) and late postoperatively (rho = 0.60). DASH and NDI scores were strongly positively correlated across operative states (Preoperative rho = 0.74, Early Postoperative rho = 0.78, Late Postoperative rho = 0.82). Stratified analysis by preoperative diagnosis showed similar within-groups trends and pairwise correlations. However, radiculopathy patients experienced larger magnitude early and late change scores.CONCLUSION:The DASH is a valid and responsive PRO measure to evaluate disabling upper extremity involvement in patients undergoing cervical spine surgery.LEVEL OF EVIDENCE:3.

BACKGROUND A number of clinical tools exist for measuring the severity of cervical spondylotic myelopathy (CSM). Several studies have recently described the use of non-invasive imaging biomarkers to assess severity of disease. These imaging markers may provide an additional tool to measure disease progression and represent a surrogate marker of response to therapy. Correlating these imaging biomarkers with clinical quantitative measures is critical for accurate therapeutic stratification and quantification of axonal injury. METHODS Fourteen patients and seven healthy control subjects were enrolled. Patients were classified as mildly (7) or moderately (7) impaired based on Modified Japanese Orthopedic Association Scale. All patients underwent diffusion tensor imaging (DTI) and diffusion basis spectrum imaging (DBSI) analyses. In addition to standard neurological examination, all participants underwent 30-m Walking Test, 9-hole Peg Test (9HPT), grip strength, key pinch, and vibration sensation thresholds in the index finger and great toe. Differences in assessment scores between controls, mild and moderate CSM patients were correlated with DTI and DBSI derived fractional anisotropy (FA). RESULTS Clinically, 30-meter walking times were significantly longer in the moderately impaired group than in the control group. Maximum 9HPT times were significantly longer in both the mildly and moderately impaired groups as compared to normal controls. Scores on great toe vibration sensation thresholds were lower in the mildly impaired and moderately impaired groups as compared to controls. We found no clear evidence for any differences in minimum grip strength, minimum key pinch, or index finger vibration sensation thresholds. There were moderately strong associations between DTI and DBSI FA values and 30-meter walking times and 9HPT. CONCLUSIONS The 30-m Walking Test and 9HPT were both moderately to strongly associated with DTI/DBSI FA values. FA may represent an additional measure to help differentiate and stratify patients with mild or moderate CSM.

Study Design: A nonrandomized, two-armed prospective study. Objective: Water-tight dural closure is paramount to the prevention of cerebrospinal fluid (CSF) leakage and associated complications. Synthetic polyethylene glycol (PEG) hydrogel has been used as an adjunct to sutured dural repair; however, its expansion postoperatively is a concern for neurological complications. A low-swell formulation of PEG sealant was introduced as DuraSeal Exact Spine Sealant System (DESS). A Post-Approval Study was performed primarily to evaluate the safety and efficacy of DESS for spinal dural repair compared to current alternatives, in a large patient population, reflecting a real-world practice. Methods: A total of 36 sites in the United States enrolled 429 patients treated with DESS as an adjunct to dural repair in the spinal sealant group and 406 patients treated with all other modalities in the control arm, from October 2011 to June 2016. The primary endpoint was the incidence of CSF leak within 90 days of operation. The secondary endpoints evaluated were deep surgical site infection and neurological serious adverse events. Results: The CSF leakage in the DESS group (6.6%) was not significantly different from the control group (6.5%) ( p = .83), and there was no significant difference in the time to first leak. The two groups had no significant differences in deep surgical site infection (1.6% versus control 2.1%, p = .61) or proportion of subjects with neurological serious adverse events (2.9% versus control 1.6%, p = .516). Conclusions: DuraSeal Exact Spinal Sealant is safe when compared to current alternatives for spinal dural repair.

OBJECTIVE The incidence of suboccipital spinal metastases is rare but has increased given cancer patients' longer life expectancies. Operative treatment in this region is often challenging because of limited fixation points due to tumor lysis, as well as adjacent neural and vascular anatomy. Few studies have reported on this population of cancer patients. The purpose of this study was to evaluate clinical outcomes and complications of patients with suboccipital spinal metastases who had undergone posterior occipitocervical fixation. METHODS A single-institution database was reviewed to identify patients with suboccipital metastases who had undergone posterior-only instrumented fusion between 1999 and 2014. Clinical presentation, perioperative complications, and postoperative results were analyzed. Pain was assessed using the visual analog scale. Survival analysis was performed using a Kaplan-Meier curve. The revised Tokuhashi and the Tomita scoring systems were used for prognosis prediction. RESULTS Fifteen patients were identified, 10 men and 5 women with mean age of 64.8 ± 11.8 years (range 48-80 years). Severe neck pain without neurological deficit was the most common presentation. Primary tumors included lung, breast, bladder, myeloma, melanoma, and renal cell cancers. All tumors occurred in the axis vertebra. Preoperative Tokuhashi and Tomita scores ranged from 5 to 13 and 3 to 7, respectively. All patients had undergone occipitocervical fusion of a mean of 4.6 levels (range 2-7 levels). Median survival was 10.3 months. In all cases, neck pain markedly improved and patients were able to resume activities of daily living. The average postoperative pain score was significantly improved as compared with the average preoperative score (1.90 ± 2.56 and 5.50 ± 2.99, respectively, p = 0.01). Three patients experienced postoperative medical complications including urinary tract infection, deep vein thrombosis, myocardial infarction, and cardiac arrhythmia. In the follow-up period, no wound infections or reoperations occurred and no patients experienced spinal cord deficits from tumor recurrence. CONCLUSIONS Posterior-only occipitocervical stabilization was highly effective at relieving patients' neck pain. No instrumentation failures were noted, and no neurological complications or tumor progression causing spinal cord deficits was noted in the follow-up period.

BACKGROUND:The objective of this study is to validate the safety of hyperacute stabilization.METHODS:Patient demographics, American Spinal Injury Association (ASIA) grade on initial evaluation and serial follow up grades, hospital length of stay, Intensive Care Unit length of stay, intraoperative blood loss, postoperative length of stay, comorbidities, Injury Severity Score and complications of recumbency were recorded.RESULTS:Corroborating previous studies, our study shows polytrauma patients undergoing a hyperacute stabilization of a spinal fracture displayed a trend towards better neurological outcome and decreased hospital stays while having a similar complication rate to those operated on in a delayed fashion.CONCLUSIONS:Hyperacute stabilization can be associated with improved ASIA grades even in complete injuries.

Spinal involvement occurs frequently in cases of eosinophilic granuloma (EG), but surgical treatment is limited primarily to those with spinal instability. Involvement of the cervical spine is rare, but primarily occurs in the vertebral bodies, and is normally amenable to anterior corpectomy and spinal reconstruction. The authors describe a 27-year-old man with pathologically proven EG who presented with complete destruction of the C-1 lateral mass requiring spinal stabilization. A titanium expandable cage was used to reconstruct the weight-bearing column from the occipital condyle to the superior articular surface of C-2 from a posterior approach, with preservation of the traversing vertebral artery. To the authors' knowledge, this is the first reported instance of reconstruction of the C-1 lateral mass using an expandable metal cage, which facilitated preservation of the vertebral artery.

Retrospective analysis of inpatient and outpatient data from a single academic trauma center.To test the effectiveness of a conservative treatment algorithm for civilian spinal gunshot wounds (CSGSWs) by comprehensively evaluating neurological status and recovery, fracture type, concomitant injuries, indications for surgery, and complications.Few large studies exist to guide treatment of CSGSWs, and none have been published in nearly 20 years.A search of International Classification of Diseases, Ninth Revision (ICD-9) codes was performed for all hospital patients treated from 2003 to 2011 by either neurosurgery or orthopedic surgery to identify 159 consecutive patients who sustained CSGSWs. Mean follow-up was 13.6 months. American Spinal Injury Association grading was used to assess neurological injury.Fifty percent of patients had neurological deficits from CSGSW. Complete spinal injury was the most common injury grade; thoracic injuries had the most risk of complete injury (P < 0.001). Nearly 80% of patients had concomitant injuries to other organs. Operative treatment was more likely in patients with severe neurological injuries (P = 0.008) but was not associated with improved neurological outcomes (P = 1.00). Nonoperative treatment did not lead to any cases of late spinal instability or neurological deterioration. Overall, 31% of patients had an improvement of at least 1 American Spinal Injury Association grade by final follow-up. Nearly half of patients experienced at least 1 GSW-related complication; risk of complications was associated with neurological injury grade (P < 0.001) and operative treatment (P = 0.04).The vast majority of CSGSWs should be managed nonoperatively, regardless of neurological grade or number of spinal columns injured. Indications for surgery include spinal infection and persistent cerebrospinal fluid leaks.3.

BACKGROUND: Because of their rarity, outcomes regarding spinal atypical meningiomas (AMs) remain unclear.OBJECTIVE: To describe the recurrence rate and postoperative outcomes after resection of spinal AMs, and to discuss an appropriate resection strategy and adjuvant therapy for spinal AMs.METHODS: Data from all patients who presented with spinal AMs to 2 tertiary referral centers between 1998 and 2013 were obtained by chart review.RESULTS: From 102 patients with spinal meningioma, 20 AM tumors (7 cervical, 11 thoracic, 2 thoracolumbar) were identified in 18 patients (median age, 50 years [range, 19-75] at time of resection; 11% male; median follow-up, 32 months [range, 1-179] after resection). Before resection, patients had sensory deficits (70%), pain (70%), weakness (60%), ataxia (50%), spasticity (65%), and incontinence (35%). One tumor presented asymptomatically. Simpson grade I, II, III, and IV resection were achieved in 3 (15%), 13 (65%), 2 (10%), and 2 (10%) tumors, respectively. One patient that underwent Simpson grade III resection received adjuvant radiation therapy. After Simpson grade I-III or gross total resection, no tumors recurred (0%; confidence interval, 0%-17.6%). After Simpson grade IV resection, 1 tumor recurred (50%; confidence interval, 1.3%-98.7%). With the exception of 1 patient who had bilateral paraplegia perioperatively, all other patients experienced improvement of preoperative symptoms after surgery (median time, 3.6 months [range, 1-13] after resection).CONCLUSION: Despite published cases suggesting an aggressive clinical course for spinal AMs, this series of spinal AMs reports that gross total resection without adjuvant radiation therapy resulted in symptom resolution and low recurrence.

STUDY DESIGN:Prospective, 3:1 randomized, single-blind, multicenter investigational study.OBJECTIVE:To assess the safety and efficacy of a low-swell spinal sealant when used as an adjunct to sutured dural repair compared with standard of care methods to obtain watertight dural closure in subjects undergoing spinal surgery.SUMMARY OF BACKGROUND DATA:Watertight dural closure is paramount in spinal surgery to avoid complications of cerebrospinal fluid leak. Prior reports have proven the efficacy of a synthetic, absorbable polyethylene glycol (PEG) hydrogel sealant in spinal surgery compared with standard of care. Given the potential concerns of swelling in spinal applications, the hydrogel was modified to a low-swell formulation.METHODS:The primary endpoint was success rate in obtaining intraoperative watertight dural closure in subjects receiving PEG hydrogel sealant versus a control group of subjects receiving any standard method designed to provide intraoperative watertight closure. Subjects were evaluated at discharge and at 30 and 90 days postprocedure for cerebrospinal fluid leaks, surgical site infections, and adverse events.RESULTS:Between May 2007 and May 2009, 98 subjects (74 PEG hydrogel spinal sealant, 24 control) were randomized at 14 clinical sites in the United States. Patients treated with the PEG hydrogel spinal sealant had a significantly higher rate of watertight closure than the control (98.6% vs. 79.2%, P = 0.003). No statistical differences were seen in postoperative cerebrospinal fluid, infection, and wound healing. No neurological deficits were seen attributable to the sealant.CONCLUSION:The low-swell PEG hydrogel spinal sealant evaluated in this study has been proven safe and effective for providing watertight closure when used as an adjunct to sutured closure of intentional durotomies during spinal surgery. PEG hydrogel sealants have again proved superior to other standard of care technologies for safe, efficacious dural closure.LEVEL OF EVIDENCE:2.

STUDY DESIGN:Retrospective analysis of inpatient and outpatient data from a single academic trauma center.OBJECTIVE:To test the effectiveness of a conservative treatment algorithm for civilian spinal gunshot wounds (CSGSWs) by comprehensively evaluating neurological status and recovery, fracture type, concomitant injuries, indications for surgery, and complications.SUMMARY OF BACKGROUND DATA:Few large studies exist to guide treatment of CSGSWs, and none have been published in nearly 20 years.METHODS:A search of International Classification of Diseases, Ninth Revision (ICD-9) codes was performed for all hospital patients treated from 2003 to 2011 by either neurosurgery or orthopedic surgery to identify 159 consecutive patients who sustained CSGSWs. Mean follow-up was 13.6 months. American Spinal Injury Association grading was used to assess neurological injury.RESULTS:Fifty percent of patients had neurological deficits from CSGSW. Complete spinal injury was the most common injury grade; thoracic injuries had the most risk of complete injury (P < 0.001). Nearly 80% of patients had concomitant injuries to other organs. Operative treatment was more likely in patients with severe neurological injuries (P = 0.008) but was not associated with improved neurological outcomes (P = 1.00). Nonoperative treatment did not lead to any cases of late spinal instability or neurological deterioration. Overall, 31% of patients had an improvement of at least 1 American Spinal Injury Association grade by final follow-up. Nearly half of patients experienced at least 1 GSW-related complication; risk of complications was associated with neurological injury grade (P < 0.001) and operative treatment (P = 0.04).CONCLUSION:The vast majority of CSGSWs should be managed nonoperatively, regardless of neurological grade or number of spinal columns injured. Indications for surgery include spinal infection and persistent cerebrospinal fluid leaks.LEVEL OF EVIDENCE:3.

BACKGROUND AND IMPORTANCE:Idiopathic spinal cord herniation (ISCH) is an uncommon condition located predominantly in the thoracic spine and often associated with a remote history of a major traumatic injury. ISCH has an incompletely described presentation and unknown etiology. There is no consensus on the treatment algorithm and surgical technique, and there are few data on clinical outcomes. CLINICAL PRESENTATION:In this case series and technical report, we describe the atypical myelopathy presentation, remote history of traumatic injury, radiographic progression, treatment, and outcomes of 5 patients treated at Washington University for symptomatic ISCH. A video showing surgical repair is presented. In contrast to classic compressive myelopathy symptomatology, ISCH patients presented with an atypical myelopathy, characterized by asymmetric motor and sensory deficits and early-onset urinary incontinence. Clinical deterioration correlated with progressive spinal cord displacement and herniation observed on yearly spinal imaging in a patient imaged serially because of multiple sclerosis. Finally, compared with compressive myelopathy in the thoracic spine, surgical treatment of ISCH led to rapid improvement despite a long duration of symptoms. CONCLUSION:Symptomatic ISCH presents with atypical myelopathy and slow temporal progression and can be successfully managed with surgical repair.

BACKGROUND: C2 translaminar screws offer biomechanical stability similar to that of other C2 fixation methods but with minimal risk to neural and vascular structures.OBJECTIVE: To report our experience with the technique since 2002 and to review the pertinent literature to advance the understanding of C2 translaminar screw fixation.METHODS: Fifty-two consecutive adult patients with disorders requiring axis stabilization were treated with C2 translaminar screws by a single surgeon. All patients underwent preoperative computed tomography scans to confirm the feasibility of screw placement. Patients were followed up with serial flexion/extension radiographs and/or computed tomography scans.RESULTS: The average age in our series was 58.1 years. One hundred three C2 translaminar screws were placed (average length, 28.9 mm). No vascular or neurological injuries occurred. Of 41 patients with sufficient follow-up (average, 13.3 months) to evaluate fusion, 1 instrumentation failure/pseudoarthrosis was observed. Five patients (average age, 78.7 years) died of complications related to medical comorbidities. In the literature, 169 cases of C2 translaminar fixation have been reported, with a fusion rate of 95.3% and no vertebral artery injuries. In biomechanical studies, C2 translaminar screws perform similarly to C2 pedicle screws and may outperform C2 pars screws in intact spine models. With disrupted atlantoaxial ligaments, constructs with C2 translaminar screws may not resist lateral bending as well as those with other screws, although they have more stability than uninstrumented, intact spines.CONCLUSION: This study reports 103 C2 translaminar screws, the largest single-surgeon series to date. C2 translaminar screws are a technically feasible, low-risk option for C2 fixation, with a 97.6% fusion rate in this series.

BACKGROUND Biopsy specimens are often obtained in the evaluation of hematogenous vertebral osteomyelitis. The effect of prebiopsy antibiotic exposure on pathogen recovery is unknown. METHODS We conducted a retrospective cohort study of adult inpatients with hematogenous vertebral osteomyelitis at a tertiary care hospital from 1 January 2003 through 31 July 2007. Antibiotic exposure within 14 days before biopsy was evaluated. RESULTS Of 150 patients with hematogenous vertebral osteomyelitis, 92 (61%) underwent a biopsy (60 [65%] needle and 32 [35%] open biopsies). The median time from admission to biopsy was 3 days (range, 0-69 days). Patients who underwent biopsy were more likely to have weakness (53 [58%] biopsy vs 15 [26%] no biopsy; P<.001) and sensory loss (27 [29%] vs 6 [10%]; P=.006), but were less likely to have a positive blood culture result (28 [30%] vs 30 [52%]; P=.01). Pathogens were recovered in 61 patients (66%). Open biopsy had a higher yield than needle biopsy (29 [91%] of 32 vs 32 [53%] of 60; P<.001). Sixty patients (65%) who had biopsies performed received antibiotics ≤14 days before the procedure (median duration, 4 days; range, 1-37 days). Open biopsy predicted positive biopsy culture results (adjusted odds ratio, 8.4; 95% confidence interval, 2.2-31.8), but there was no association of prebiopsy antibiotics with culture results (adjusted odds ratio, 2.3; 95% confidence interval, 0.8-6.2). CONCLUSIONS A pathogen was recovered from 61 (66%) of 92 patients who had biopsies performed in this cohort of hematogenous vertebral osteomyelitis. Open biopsies had a higher microbiological yield than did needle biopsies. Antibiotic exposure before biopsy did not negatively impact pathogen recovery and should not be the sole reason for foregoing biopsies.