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Objective: Skull base chordomas are rare, locally osseo-destructive lesions that present unique surgical challenges due to their involvement of critical neurovascular and bony structures at the craniovertebral junction (CVJ). Radical cytoreductive surgery improves survival but also carries significant morbidity, including the potential for occipitocervical (OC) destabilization requiring instrumented fusion. The published experience on OC fusion after CVJ chordoma resection is limited, and the anatomical predictors of OC instability in this context remain unclear., Methods: PubMed and Embase were systematically searched according to the PRISMA guidelines for studies describing skull base chordoma resection and OC fusion. The search strategy was predefined in the authors' PROSPERO protocol (CRD42024496158)., Results: The systematic review identified 11 surgical case series describing 209 skull base chordoma patients and 116 (55.5%) who underwent OC instrumented fusion. Most patients underwent lateral approaches (n = 82) for chordoma resection, followed by midline (n = 48) and combined (n = 6) approaches. OC fusion was most often performed as a second-stage procedure (n = 53), followed by single-stage resection and fusion (n = 38). The degree of occipital condyle resection associated with OC fusion was described in 9 studies: total unilateral condylectomy reliably predicted OC fusion regardless of surgical approach. After lateral transcranial approaches, 4 studies cited at least 50%-70% unilateral condylectomy as necessitating OC fusion. After midline approaches-most frequently the endoscopic endonasal approach (EEA)-at least 75% unilateral condylectomy (or 50% bilateral condylectomy) led to OC fusion. Additionally, resection of the medial atlantoaxial joint elements (the C1 anterior arch and tip of the dens), usually via EEA, reliably necessitated OC fusion. Two illustrative cases are subsequently presented, further exemplifying how the extent of CVJ bony elements removed via EEA to achieve complete chordoma resection predicts the need for OC fusion., Conclusions: Unilateral total condylectomy, 50% bilateral condylectomy, and resection of the medial atlantoaxial joint elements were the most frequently described independent predictors of OC fusion in skull base chordoma resection. Additionally, consistent with the occipital condyle harboring a significantly thicker joint capsule at its posterolateral aspect, an anterior midline approach seems to tolerate a greater degree of condylar resection (75%) than a lateral transcranial approach (50%-70%) prior to generating OC instability.

Objective: The present study utilized recently developed in-construct measurements in simulations of cervical deformity surgery in order to assess undercorrection and predict distal junctional kyphosis (DJK)., Methods: A retrospective review of a database of operative cervical deformity patients was analyzed for severe DJK and mild DJK. C2-lower instrumented vertebra (LIV) sagittal angle (SA) was measured postoperatively, and the correction was simulated in the preoperative radiograph in order to match the C2-LIV by using the planning software. Linear regression analysis that used C2 pelvic angle (CPA) and pelvic tilt (PT) determined the simulated PT that matched the virtual CPA. Linear regression analysis was used to determine the C2-T1 SA, C2-T4 SA, and C2-T10 SA that corresponded to DJK of 20° and cervical sagittal vertical axis (cSVA) of 40 mm., Results: Sixty-nine cervical deformity patients were included. Severe and mild DJK occurred in 11 (16%) and 22 (32%) patients, respectively; 3 (4%) required DJK revision. Simulated corrections demonstrated that severe and mild DJK patients had worse alignment compared to non-DJK patients in terms of cSVA (42.5 mm vs 33.0 mm vs 23.4 mm, p < 0.001) and C2-LIV SVA (68.9 mm vs 57.3 mm vs 36.8 mm, p < 0.001). Linear regression revealed the relationships between in-construct measures (C2-T1 SA, C2-T4 SA, and C2-T10 SA), cSVA, and change in DJK (all R > 0.57, p < 0.001). A cSVA of 40 mm corresponded to C2-T4 SA of 10.4° and C2-T10 SA of 28.0°. A DJK angle change of 10° corresponded to C2-T4 SA of 5.8° and C2-T10 SA of 20.1°., Conclusions: Simulated cervical deformity corrections demonstrated that severe DJK patients have insufficient corrections compared to patients without DJK. In-construct measures assess sagittal alignment within the fusion separate from DJK and subjacent compensation. They can be useful as intraoperative tools to gauge the adequacy of cervical deformity correction.

Background: Up to 10% of cervical spine surgeries are complicated by postoperative weakness. Although many patients recover with nonoperative management, some require surgery for restoration of function., Objective: To present the indications and outcomes of patients undergoing nerve transfers after developing weakness secondary to cervical spine decompression., Methods: A retrospective review of patients from 2 academic medical centers who underwent nerve transfer for C5-6 root injury after cervical spine surgery was performed., Results: Of the 10 treated patients, 9 experienced recovery at last follow-up, demonstrating improvements in strength and motion in the affected muscles. Successful nerve transfers occurred between 3 and 8 months after the index spinal surgery and included spinal accessory nerve to suprascapular nerve, triceps branch to anterior division of the axillary nerve, and/or ulnar or median fascicles to motor branches of the musculocutaneous nerve. The unsuccessful patient underwent nerve transfer surgery approximately 11 months after the index operation and failed to obtain functional recovery., Conclusions: Patients who experience C5-6 weakness after cervical spine surgery should be evaluated and considered for nerve transfer surgery if they have continued severe functional deficits at 6 months postoperatively. Earlier referral for nerve transfer is associated with improved functional outcomes in this cohort., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Objective: To propose a surgical approach algorithm for the tumors of the cervicothoracic spine., Methods: All patients operated for vertebral column tumors involving the occipito-cervicothoracic spine were reviewed. Oncologic characteristics and surgical approach were gathered. Approach was classified by the use of staging and trajectory (posterior, transnasal, transoral, transmandibular, transcervical, transsternal). Angle of attack was defined for the occipitocervical junction tumor as the angle inscribed by the inferior mandibular plane and line connecting the superior tumor pole and mandibular angle. For lesions extending below the thoracic inlet, angle of attack was that inscribed by the plane of the thoracic inlet and the line connecting the jugular notch and inferior tumor pole., Results: In total, 115 patients were included (mean age 56.7 years, 64 [56%] male, average size 26.5 cm 3 , 39 [34%] primary tumors). Sixty-nine (60%) of patients had single-stage procedures (57 [49.6%] posterior-only, 12 [10.4%] anterior-only), 35 (30.4%) had 2-stage procedures, and 11 (9.6%) had 3- or 4-stage approaches. Lesions requiring a combined transmandibular-transcervical approach all involved the C2 and C3 levels and had a significantly steeper angle of attack (42.5 ± 9.5 vs. 6.1 ± 13.3°; P = 0.01) and greater superior tumor extent above the inferior plane of the mandible (3.69 ± 2.18 vs. 0.33 ± 0.78; P = 0.002). Lateral tumor extent, tumor size, nor inferior angle of attack differed significantly between approach groups., Conclusions: Here, we present a preliminary decision-making algorithm for the management of vertebral column tumors of the cervicothoracic spine. Based on this single-center experience, we suggest which patients, assessed via a combination of tumor histology and regional anatomy, may benefit from extended anterior surgical access., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The objective of this study was to examine the association between electrophysiology data post-C5-palsy and referral to peripheral nerve surgeons (PNS) using a 15-year cohort of patients who underwent posterior cervical decompression. Endpoints included the associations of postoperative treatments employed with functional recovery and abnormal electrophysiology data. Of 77 included patients (median 64 yr; 68% male), 48% completely recovered. The most common treatments were physical therapy (90%), occupational therapy (34%), oral corticosteroids (18%), and PNS referral (17%). Baseline weakness did not associate with PNS referral or postoperative treatment strategy. None of the treatments predicted recovery, though patients with no [versus complete] recovery were more likely to be recommended for nerve transfers (22.2 vs 0%; p = 0.03). Abnormal electromyography data associated with PNS referral (p < 0.01), nerve transfer recommendation (p < 0.01), occupational therapy referral, and oral corticosteroid therapy. Abnormal findings on EMG obtained between 6-weeks and 6-months post-injury were the most strongly associated with peripheral nerve surgeon referral (p = 0.02) and nerve transfer recommendation (p < 0.01). These data suggest strategies for postoperative C5 palsy management are highly heterogeneous. None of the treatments employed significantly predicted the extent of functional recovery. However, patients with abnormal electrophysiology results were most likely to receive multimodal treatment, suggesting these results may significantly alter medical management of patients with postoperative C5 palsy. Early (6-week to 6-month) electrophysiology data may help to ensure that patients likely to benefit from nerve transfer procedures are referred to a PNS within the 9-12-month time frame associated with the best recovery of function., Competing Interests: Declaration of Competing Interest Zach Pennington, Daniel Lubelski, Nikita Lakomkin, Benjamin D Elder, Sheng-Fu Lo: None. Timothy F. Witham: Consultant for DePuy Synthes. Advisory board member and shareholder of Augmedics. Non-study-related grant support from Gordon and Marilyn Macklin Foundation. Daniel M. Sciubba: Consultant for Baxter, DePuy-Synthes, Medtronic, Stryker., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This retrospective cohort study describes adult cervical deformity(ACD) patients with Ames-ACD classification at baseline(BL) and 1-year post-operatively and assesses the relationship of improvement in Ames modifiers with clinical outcomes. Patients ≥ 18yrs with BL and post-op(1-year) radiographs were included. Patients were categorized with Ames classification by primary deformity descriptors (C = cervical; CT = cervicothoracic junction; T = thoracic; S = coronal) and alignment/myelopathy modifiers(C2-C7 Sagittal Vertical Axis[cSVA], T1 Slope-Cervical Lordosis[TS-CL], Horizontal Gaze[Horiz], mJOA). Univariate analysis evaluated demographics, clinical intervention, and Ames deformity descriptor. Patients were evaluated for radiographic improvement by Ames classification and reaching Minimal Clinically Important Differences(MCID) for mJOA, Neck Disability Index(NDI), and EuroQuol-5D(EQ5D). A total of 73 patients were categorized: C = 41(56.2%), CT = 18(24.7%), T = 9(12.3%), S = 5(6.8%). By Ames modifier 1-year improvement, 13(17.8%) improved in mJOA, 26(35.6%) in cSVA grade, 19(26.0%) in Horiz, and 15(20.5%) in TS-CL. The overall proportion of patients without severe Ames modifier grades at 1-year was as follows: 100% cSVA, 27.4% TS-CL, 67.1% Horiz, 69.9% mJOA. 1-year post-operatively, severe myelopathy(mJOA = 3) prevalence differed between Ames-ACD descriptors (C = 26.3%, CT = 15.4%, T = 0.0%, S = 0.0%, p = 0.033). Improvement in mJOA modifier correlated with reaching 1-year NDI MCID in the overall cohort (r = 0.354,p = 0.002). For C descriptors, cSVA improvement correlated with reaching 1-year NDI MCID (r = 0.387,p = 0.016). Improvement in more than one radiographic Ames modifier correlated with reaching 1-year mJOA MCID (r = 0.344,p = 0.003) and with reaching more than one MCID for mJOA, NDI, and EQ-5D (r = 0.272,p = 0.020). In conclusion, improvements in radiographic Ames modifier grades correlated with improvement in 1-year postoperative clinical outcomes. Although limited in scope, this analysis suggests the Ames-ACD classification may describe cervical deformity patients' alignment and outcomes at 1-year., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier Ltd.)

Background: Myelopathy is thought to be associated with higher morbidity and mortality after anterior cervical discectomy and fusion (ACDF); however, the literature investigating this association has limitations., Objective: To investigate the influence of myelopathy on early perioperative complications of elective single-level ACDF., Methods: Patients who underwent ACDF between 2016 and 2018 were reviewed from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. Propensity score matching analysis was used., Results: Twenty percent of the cohort was myelopathic. These patients were significantly older, had more comorbidities, more likely to be functionally dependent, and to undergo emergency surgery when compared to the nonmyelopathic cohort. When 1969 myelopathic patients were 1:1 propensity matched with nonmyelopathic patients, there was no difference between the myelopathic and nonmyelopathic patients in incidence of postoperative intensive care unit admission or death. Patients in the myelopathic group were significantly more likely to have a nonhome discharge and less likely to be discharged on the first postoperative day. Myelopathic patients had a higher rate of return to operating room within the same admission (2.2%) as well as a higher unplanned readmission rate (4.2%). The total operation time (143 min) and average length of hospital stay (52 h) were significantly higher in the myelopathic group when compared to the nonmyelopathic group (117 min) and (33 h), respectively., Conclusion: Patients with myelopathy who undergo elective single-level ACDF have higher risks of several perioperative events including longer operative time, longer hospital stay, higher return to operating room, and unplanned readmission rates, when compared to nonmyelopathic patients. On the other hand, myelopathic patients did not exhibit higher mortality rate., (© Congress of Neurological Surgeons 2021.)

Background: C5 palsy affects approximately 5% to 10% of patients undergoing cervical spine surgery. It has a significant negative impact on patient quality-of-life outcomes and healthcare costs. Although >80% of patients improve, some are left with persistent, debilitating deficits. Our objective was to examine if electrodiagnostic testing could be used to successfully identify patients likely to experience complete, partial, and no recovery., Methods: Patients undergoing posterior cervical decompression and fusion at a single institution over a 10-year period were identified. Those experiencing postoperative C5 palsy were included. Outcomes examined included motor recovery of the affected deltoid as a function of time, and changes in electrodiagnostic testing as a function of time since injury. Electrodiagnostic testing included electromyography and was sub-analyzed by time of acquisition postinjury. Deltoid strength was graded on manual motor testing using the 5-point medical research council grading system., Results: Of 77 patients experiencing C5 palsy, 29 had postoperative electrodiagnostic testing. Patients experiencing complete recovery on average achieved functional (4/5) strength by 6-weeks post injury and 4+ per 5 strength by 6-months. Those experiencing partial recovery only achieved antigravity strength (3/5) by 6-weeks and low-function (4-/5) strength by 6-months. Electrodiagnostic testing performed 6-weeks to 6-months postinjury demonstrated that those experiencing complete recovery were more likely to have normal motor unit (MU) recruitment than those experiencing partial (p<.001) or no recovery (p=.008). The presence of ≥2+ fibrillation on tests acquired ≤6-weeks of injury identified patients unlikely to experience any recovery with a positive predictive value (PPV) of 88.9%. The presence of normal MU recruitment on tests acquired 6-weeks to 6-months postinjury identified patients likely to experience complete recovery with a PPV of 87.5%., Conclusions: Electrodiagnostic testing may be a valuable means of differentiating between patients with C5 palsy likely to experience complete, partial, or no recovery. Testing between 6-weeks and 6-months post onset may aid in identifying those least likely to have a complete recovery. No MUs at 4 to 6-months, or reduced units with strength that is not improving, portends a poor long-term outcome. In this population, peripheral nerve transfers may be considered sooner., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: Postoperative C5 palsy is a debilitating complication following posterior cervical decompression., Objective: To create a simple clinical risk score predicting the occurrence of C5 palsy., Methods: We retrospectively reviewed all patients who underwent posterior cervical decompressions between 2007 and 2017. Data was randomly split into training and validation datasets. Multivariable analysis was performed to construct the model from the training dataset. A scoring system was developed based on the model coefficients and a web-based calculator was deployed., Results: The cohort consisted of 415 patients, of which 65 (16%) developed C5 palsy. The optimal model consisted of: mean C4/5 foraminal diameter (odds ratio [OR] = 9.1 for lowest quartile compared to highest quartile), preoperative C5 radiculopathy (OR = 3.5), and dexterity loss (OR = 2.9). The receiver operating characteristic yielded an area under the curve of 0.757 and 0.706 in the training and validation datasets, respectively. Every characteristic was worth 1 point except the lowest quartile of mean C4/5 foraminal diameter, which was worth 2 points, and the factors were summarized by the acronym F2RaD. The median predicted probability of C5 palsy increased from 2% in patients with a score of 0 to 70% in patients with a score of 4. The calculator can be accessed on https://jhuspine2.shinyapps.io/FRADscore/., Conclusion: This study yielded a simplified scoring system and clinical calculator that predicts the occurrence of C5 palsy. Individualized risk prediction for patients may facilitate better understanding of the risks and benefits for an operation, and better prepare them for this possible adverse outcome. Furthermore, modifying the surgical plan in high-risk patients may possibly improve outcomes., (Copyright © 2020 by the Congress of Neurological Surgeons.)

Objective: The aim of this study was to investigate whether race is an independent predictor of extended length of stay (LOS) after elective anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM)., Methods: A retrospective cohort study was performed using the National Inpatient Sample database from 2016 to 2017. All adult patients undergoing ACDF for CSM were identified using the International Classification of Diseases, Tenth Revision, Clinical Modification coding system., Results: A total of 15,400 patients were identified, of whom 13,250 (86.0%) were Caucasian (C) and 2150 (14.0%) were African American (AA). The C cohort tended to be older, whereas the AA cohort had 2 times as many patients in the 0-25th income quartile. The prevalence of comorbidities was greater in the AA cohort. Intraoperative fusion levels were similar between the cohorts, whereas the AA cohort had a higher rate of cerebrospinal fluid leak/dural tear. In relation to the number of complications, the C cohort had a lower rate compared with the AA cohort (P = 0.006), including no complication (89.4% vs. 85.3%), 1 complication (9.9% vs. 12.8%), and >1 complication (0.7% vs. 1.9%). The AA cohort experienced significantly longer hospital stays (C, 1.9 ± 2.3 days vs. AA, 2.7 ± 3.5; P < 0.001), greater proportion of extended LOS (C, 17.5% vs. AA, 29.1%; P < 0.001) and nonroutine discharges (C, 16.1% vs. AA, 28.6%; P < 0.001). AA race was a significant independent risk factor for extended LOS (odds ratio, 1.98; 95% confidence interval, 1.50-2.61; P < 0.001)., Conclusions: Our study suggests that AA patients have a significantly higher risk of prolonged LOS after elective ACDF for CSM compared with C patients., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Objective: Tumors of the cervical spine often encase 1 or both vertebral arteries (VA), presenting the treating surgeon with the dilemma of whether to sacrifice or skeletonize the artery. We propose an algorithm for VA management in surgeries for cervical neoplasms METHODS: A retrospective review was carried out of 67 patients undergoing resection of cervical spine tumors with VA involvement. Patients were categorized by tumor origin (primary vs. metastatic) and degree of circumferential VA involvement: 1) abutment only; 2) <180° circumferential involvement; 3) >180° circumferential involvement without complete encasement; or 4) complete encasement., Results: Twelve patients (18%) underwent VA sacrifice, whereas 55 (82%) underwent VA skeletonization. Compared with 11/30 patients with primary tumors (37%), only 1/37 patients (3%) with metastatic disease underwent VA sacrifice (P < 0.01). This patient had invasion of the V2 arterial wall, requiring VA sacrifice. Odds of VA sacrifice also increased with increasing circumferential involvement (P < 0.01). No patients with simple abutment or 0°-180° circumferential involvement underwent sacrifice, whereas 6 of 10 (60%) with 180°-359° involvement and 6 of 29 (21%) with complete encasement underwent VA sacrifice. Of the 27 patients with ≥180° involvement, the reasons for preserving the VA were metastatic disease at the time of treatment (n = 18), a compromised contralateral VA (n = 7), vertebrobasilar junction aplasia (n = 1), and presence of a radiculomedullary artery at the affected level (n = 1)., Conclusions: Primary tumor disease and >180° of circumferential VA involvement should be considered as indications for intraoperative sacrifice of the VA pending preoperative angiographic evaluation for contraindications., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Cervical alignment has become increasingly important in the planning of spine surgery. A relationship between the slope of T1 (T1S), the cervical lordosis (CL), and the overall cervical sagittal vertical axis (cSVA) has previously been demonstrated, but the exact nature of this relationship is poorly understood. In this study, we derive theoretical and empirical equations to better understand how T1S and CL affect cSVA. The first equation was developed on a theoretical basis using inherent trigonometric relationships of the cervical spine. By treating the cervical spine as the arc of a circumference, and by taking into account the cervical height (CH), the geometric relationship between theT1S, CL, and cSVA was described via a trigonometric identity utilizing a novel angle δ subtended by the CH and cSVA (δ = T1S-CL/2). The second equation was developed on an empiric basis by performing a multiple linear regression on data obtained from a retrospective review of a large multicenter deformity database. The theoretical equation determined that the value of cSVA could be expressed as: $cSVA\ = \ CH*{\rm{tan}}( {\pi /180*( {T1S - CL/2} )} )$. The empirical equation determined that value of cSVA could be expressed as: $cSVA=({1.1*T1} )\ - ( {0.43*CL} ) + 6.69$. In both, the sagittal alignment of the head over the shoulders is directly proportional to the T1S and inversely proportional to CL/2. These 2 equations may allow surgeons to better understand how the CL compensates for the T1S, to accurately predict the postoperative cSVA, and to customize cervical interbody grafts by taking into consideration each individual patient's specific cervical spine parameters., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Background: Of the more than 30,000 posterior cervical spine fusions performed annually, 7%-12% will be complicated by postoperative C5 palsy, a condition characterized by new-onset deltoid weakness with or without C5 dermatomal findings and biceps weakness. Posterior translation of the cervical spinal cord has been proposed as a risk factor for this complication., Purpose: To evaluate if C5 palsy can be predicted by spinal cord float back., Study Design/setting: Retrospective cohort., Patient Sample: Patients ≥18 years of age undergoing posterior cervical decompression between 2002 and 2017 for degenerative cervical spine pathologies., Outcome Measures: Occurrence of C5 palsy as evaluated by manual motor testing (MMT)., Methods: We recorded baseline neurological status, operative notes, details of postoperative course, and both pre- and postoperative magnetic resonance imaging images. Float back was defined by the change in the distance between the spinal cord and posterior face of the C4/5 annulus from preoperative to postoperative imaging. C5 palsy was defined by new-onset deltoid weakness on MMT., Results: We identified 242 patients with a mean age of 62.4 years and mean follow-up of 27.9 months. Forty-two (17.4%) experienced postoperative C5 palsy. On univariable analysis, significant predictors of postoperative C5 palsy were mean C4/5 foraminal diameter (2.8 vs. 3.2 mm; p<.001), anterior projection of the C5 superior articular process (4.12 vs. 3.70 mm; p=.04), cord float back (0.35 vs. 0.28 cm; p=.02), undergoing laminectomy of the C5 (p=.02) or C4 and C5 levels (p=.02), and undergoing instrumented fusion extending one level above and below the C4/5 level. Foraminotomy of the C4/5 level was not predictive of postoperative palsy. On multivariable analysis mean C4/5 foraminal diameter (odds ratio=0.38 per mm; p<.01) predicted C5 palsy; cord float back at the C4/5 level was not predictive of C5 palsy., Conclusions: Spinal cord float back was not an independent predictor of C5 palsy on multivariable analysis. Only smaller foraminal diameter was independently predictive of postoperative C5 palsy. This suggests that chronic preoperative compression of the C5 roots, not postdecompression float back may be the biggest contributor to the etiology of postoperative C5 palsy., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Purpose: To assess preliminary associations between fatty-infiltration (FI) of cervical spine extensor musculature, cervical sagittal balance, and clinical outcomes in cervical deformity (CD) patients., Methods: Operative CD patients (C2-C7 Cobb > 10°, CL > 10°, cSVA > 4 cm, or CBVA > 25°) with pre-operative (BL) MRIs and 1-year (1Y) post-operative MRIs or CTs were assessed for fatty-infiltration of cervical extensor musculature, using dedicated imaging software at each C2-C7 intervertebral level and the apex of deformity (apex). FI was gauged as a ratio of fat-free-muscle-cross-sectional-area (FCSA) over total-muscle-CSA (TCSA), with lower ratio values indicating greater FI. BL-1Y associations between FI, sagittal alignment, and clinical outcomes were assessed using appropriate parametric and non-parametric tests., Results: 22 patients were included (Age 59.22, 71.4%F, BMI 29.2, CCI:0.75, Frailty: 0.43). BL deformity presentation: TS-CL: 29.0°, C2-C7 Sagittal Cobb:-1.6°, cSVA:30.4 mm. No correlations were observed between BL fatty-infiltration, sagittal alignment, frailty, or clinical outcomes (p > 0.05). Following surgical correction, C2-C7 (BL: 0.59 vs 1Y:0.67, p = 0.005) and apex (BL: 0.59 vs. 1Y: 0.66, p = 0.33) fatty-infiltration decreased. Achievement of lordotic curvature correlated with C2-C7 fatty infiltration reduction (R s : 0.495, p < 0.05), and patients with residual postoperative TS-CL and cSVA malalignment were associated with greater apex fatty-infiltration (R s : -0.565, -0.561; p < 0.05). C2-C7 FI improvement was associated with NRS back pain reduction (R s : -0.630, p < 0.05), and greater apex fatty-infiltration at BL was associated with minor perioperative complication occurrence (R s : 0.551, p = 0.014)., Conclusions: Deformity correction and sagittal balance appear to influence the reestablishment of cervical muscle tone from C2-C7 and reduction of back pain for severely frail CD patients. This analysis helps to understand cervical extensor musculature's role amongst CD patients., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Study Design: Retrospective review., Objective: The aim of this study was to develop a novel surgical invasiveness index for cervical deformity (CD) surgery that incorporates CD-specific parameters., Summary of Background Data: There has been a surgical invasiveness index for general spine surgery and adult spinal deformity, but a CD index has not been developed., Methods: CD was defined as at least one of the following: C2-C7 Cobb >10°, cervical lordosis (CL) >10°, cervical sagittal vertical axis (cSVA) >4 cm, chin brow vertical angle >25°. Consensus from experienced spine and neurosurgeons selected weightings for each variable that went into the invasiveness index. Binary logistic regression predicted high operative time (>338 minutes), estimated blood loss (EBL) (>600 mL), or length of stay (LOS) >5 days) based on the median values of operative time, EBL, and LOS. Multivariable regression modeling was utilized to construct a final model incorporating the strongest combination of factors to predict operative time, LOS, and EBL., Results: Eighty-five CD patients were included (61 years, 66% females). The variables in the newly developed CD invasiveness index with their corresponding weightings were: history of previous cervical surgery (3), anterior cervical discectomy and fusion (2/level), corpectomy (4/level), levels fused (1/level), implants (1/level), posterior decompression (2/level), Smith-Peterson osteotomy (2/level), three-column osteotomy (8/level), fusion to upper cervical spine (2), absolute change in T1 slope minus cervical lordosis, cSVA, T4-T12 thoracic kyphosis (TK), and sagittal vertical axis (SVA) from baseline to 1-year. The newly developed CD-specific invasiveness index strongly predicted long LOS (R = 0.310, P < 0.001), high EBL (R = 0.170, P = 0.011), and extended operative time (R = 0.207, P = 0.031). A second analysis used multivariable regression modeling to determine which combination of factors in the newly developed index were the strongest determinants of operative time, LOS, and EBL. The final predictive model included: number of corpectomies, levels fused, decompression, combined approach, and absolute changes in SVA, cSVA, and TK. This model predicted EBL (R = 0.26), operative time (R = 0.12), and LOS (R = 0.13)., Conclusion: Extended LOS, operative time, and high blood loss were strongly predicted by the newly developed CD invasiveness index, incorporating surgical factors and radiographic parameters clinically relevant for patients undergoing CD corrective surgery., Level of Evidence: 4.

Background: Horner syndrome is an infrequently seen complication of anterior cervical discectomy and fusion (ACDF). Multicenter studies have reported a very low incidence, less than 0.1%., Objective: To identify the incidence in, characteristics of, and postoperative course in patients in whom postoperative Horner syndrome developed after ACDF., Methods: We performed a retrospective review of all patients who experienced Horner syndrome after ACDF for cervical degenerative disease at a single tertiary care institution between 2017 and 2018. A systematic review was then performed to identify studies investigating prevalence, diagnosis, and treatment of postoperative Horner syndrome after ACDF., Results: Of 1116 patients at our institution who underwent ACDF, the incidence of Horner syndrome was 0.45%. C4/5 and C5/6 were the 2 most common surgical levels. The complication was noted to occur immediately after surgery, and at least partial improvement was identified in all patients an average 3.5 months after surgery (range, 10 days to 6 months). These findings were consistent with our systematic review of 21 studies that showed an incidence of 0.6% (range, 0.02% to 4.0%), the most common surgical level C5/6 (64%), and 82% of patients experiencing at least partial resolution of symptoms within 1 year (60.7% complete, 21.4% partial resolution)., Conclusion: Horner syndrome occurs in 0.6% of patients undergoing ACDF. Careful postoperative examination should reveal this complication, which may be underdiagnosed or underreported in larger multicenter case series. The majority of patients experience complete resolution of symptoms within 6 months to 1 year and can be treated conservatively and expectantly., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Study Design: Retrospective cohort study., Objective: To evaluate the risks and benefits of crossing the cervicothoracic junction (CTJ) in cervical arthrodesis., Summary of Background Data: Whether the CTJ should be crossed in cervical arthrodesis remains up for debate. Keeping C7 as the distal end of the fusion risks adjacent segment disease (ASD) and can result in myelopathy or radiculopathy. Longer fusions are thought to increase operative risk and complexity but result in lower rates of ASD., Materials and Methods: Patients undergoing cervical spine fusion surgery ending at C7 or T1 with ≥1-year follow-up were included. To evaluate operative risk, estimated blood loss (EBL), operative time, and length of hospital stay were collected. To evaluate patient-reported outcomes (PROs), Neck Disability Index (NDI) and SF-12 questionnaires (PCS12 and MCS12) were obtained at follow-up. Revision surgery data were also obtained., Results: A total of 168 patients were included and divided into a C7 end-of-fusion cohort (NC7=59) and a T1 end-of-fusion cohort (NT1=109). Multivariate regression analysis adjusting for age, sex, race, surgical approach, and number of levels fused showed that EBL (P=0.12), operative time (P=0.07), and length of hospital stay (P=0.06) are not significantly different in the C7 and T1 end-of-fusion cohorts. Multivariate regression of PROs showed no significant difference in NDI (P=0.70), PCS12 (P=0.23), or MCS12 (P=0.15) between cohorts. Fisher analysis showed significantly higher revision rates in the C7 end-of-fusion cohort (7/59 for C7 vs. 2/109 for T1; odds ratio, 6.4; 95% confidence interval, 1.2-65.1; P=0.01)., Conclusions: Crossing the CTJ in cervical arthrodesis does not increase operative risk as measured by blood loss, operative time, and length of hospital stay. However, it leads to lower revision rates, likely because of the avoidance of ASD, and comparable PROs. Thus, crossing the CTJ may help prevent ASD without negatively affecting operative risk or long-term PROs.

Objective: Postoperative C5 palsy affects 7%-12% of patients who undergo posterior cervical decompression for degenerative cervical spine pathologies. Minimal evidence exists regarding the natural history of expected recovery and variables that affect palsy recovery. The authors investigated pre- and postoperative variables that predict recovery and recovery time among patients with postoperative C5 palsy., Methods: The authors included patients who underwent posterior cervical decompression at a tertiary referral center between 2004 and 2018 and who experienced postoperative C5 palsy. All patients had preoperative MR images and full records, including operative note, postoperative course, and clinical presentation. Kaplan-Meier survival analysis was used to evaluate both times to complete recovery and to new neurological baseline-defined by deltoid strength on manual motor testing of the affected side-as a function of clinical symptoms, surgical maneuvers, and the severity of postoperative deficits., Results: Seventy-seven patients were included, with an average age of 64 years. The mean follow-up period was 17.7 months. The mean postoperative C5 strength was grade 2.7/5, and the mean time to first motor examination with documented C5 palsy was 3.5 days. Sixteen patients (21%) had bilateral deficits, and 9 (12%) had new-onset biceps weakness; 36% of patients had undergone C4-5 foraminotomy of the affected root, and 17% had presented with radicular pain in the dermatome of the affected root. On univariable analysis, patients' reporting of numbness or tingling (p = 0.02) and a baseline deficit (p < 0.001) were the only predictors of time to recovery. Patients with grade 4+/5 weakness had significantly shorter times to recovery than patients with grade 4/5 weakness (p = 0.001) or ≤ grade 3/5 weakness (p < 0.001). There was no difference between those with grade 4/5 weakness and those with ≤ grade 3/5 weakness. Patients with postoperative strength < grade 3/5 had a < 50% chance of achieving complete recovery., Conclusions: The timing and odds of recovery following C5 palsy were best predicted by the magnitude of the postoperative deficit. The use of C4-5 foraminotomy did not predict the time to or likelihood of recovery.

Background: Nonroutine discharge, including discharge to inpatient rehab and skilled nursing facilities, is associated with increased cost-of-care. Given the rising prevalence of cervical deformity (CD)-corrective surgery and the necessity of value-based healthcare, it is important to identify indicators for nonroutine discharge., Objective: To identify factors associated with nonroutine discharge after CD-corrective surgery using a statistical learning algorithm., Methods: A retrospective review of patients ≥18 yr with discharge and baseline (BL) radiographic data. Conditional inference decision trees identified factors associated with nonroutine discharge and cut-off points at which factors were significantly associated with discharge status. A conditional variable importance table used nonreplacement sampling set of 10 000 conditional inference trees to identify influential patient/surgical factors. The binary logistic regression indicated odds of nonroutine discharge for patients with influential factors at significant cut-off points., Results: Of 138 patients (61 yr, 63% female) undergoing surgery for CD (8 ± 5 levels; 49% posterior approach, 16% anterior, and 35% combined), 29% experienced nonroutine discharge. BL cervical/upper-cervical malalignment showed the strongest relationship with nonroutine discharge: C1 slope ≥ 14°, C2 slope ≥ 57°, TS-CL ≥ 57°. Patient-related factors associated with nonroutine discharge included BL gait impairment, age ≥ 59 yr and apex of CD primary driver ≥ C7. The only surgical factor associated with nonroutine discharge was fusion ≥ 8 levels. There was no relationship between nonhome discharge and reoperation within 6 mo or 1 yr (both P > .05) of index procedure. Despite no differences in BL EQ-5D (P = .946), nonroutine discharge patients had inferior 1-yr postoperative EQ-5D scores (P = .044)., Conclusion: Severe preoperative cervical malalignment was strongly associated with nonroutine discharge following CD-corrective surgery. Age, deformity driver, and ≥ 8 level fusions were also associated with nonroutine discharge and should be taken into account to improve patient counseling and health care resource allocation., (Copyright © 2019 by the Congress of Neurological Surgeons.)

Study Design: This is a retrospective review of prospective multicenter cervical deformity (CD) database., Objective: Assess the impact of complication type and Clavien complication (Cc) grade on clinical outcomes of surgical CD patients BACKGROUND:: Validated for general surgery, the Clavien-Dindo complication classification system allows for broad comparison of postoperative complications; however, the applicability of this system is unclear in CD-specific populations., Methods: Surgical CD patients above 18 years with baseline and postoperative clinical data were included. Primary outcomes were complication type (renal, infection, cardiac, pulmonary, gastrointestinal, neurological, musculoskeletal, implant-related, radiographic, operative, wound) and Cc grade (I, II, III, IV, V). Secondary outcomes were estimated blood loss (EBL), length of stay (LOS), reoperation, and health-related quality of life (HRQL) score. The univariate analysis assessed the impact of complication type and Cc grade on improvement markers and 1-year postoperative HRQL outcomes., Results: In total, 153 patients (61±10 y, 61% female) underwent surgery for CD (8.1±4.6 levels fused; surgical approach included 48% posterior, 18% anterior, 34% combined). Overall, 63% of patients suffered at least 1 complication. Complication breakdown by type: renal (2.0%), infection (5.2%), cardiac (7.2%), pulmonary (3.9%), gastrointestinal (2.0%), neurological (26.1%), musculoskeletal (0.0%), implant-related (3.9%), radiographic (16.3%), operative (7.8%), and wound (5.2%). Of complication types, only operative complications were associated with increased EBL (P=0.004), whereas renal, cardiac, pulmonary, gastrointestinal, neurological, radiographic, and wound infections were associated with increased LOS (P<0.050). Patients were also assessed by Cc grade: I (28%), II (14.3%), III (16.3%), IV (6.5%), and V (0.7%). Grades I and V were associated with increased EBL (both P<0.050); Cc grade V was the only complication not associated with increased LOS (P=0.610). Increasing complication severity was correlated with increased risk of reoperation (r=0.512; P<0.001), but not inferior 1-year HRQL outcomes (all P>0.05)., Conclusions: Increasing complication severity, assessed by the Clavien-Dindo classification system, was not associated with increased EBL, inpatient LOS, or inferior 1-year postoperative HRQL outcomes. Only operative complications were associated with increased EBL. These results suggest a need for modification of the Clavien system to increase applicability and utility in CD-specific populations.

Background: Postoperative C5 palsy affects 8% of patients undergoing posterior cervical decompression. It is associated with a period functional disability that may exceed 12 months and increase direct care costs > $2000., Methods: All patients undergoing posterior cervical decompression at a single tertiary-care facility for degenerative conditions were evaluated for preoperative imaging, clinical presentation, surgical operation, and postoperative course. We sought to identify those variables predictive of postoperative C5 palsy., Results: Of 221 included patients (mean age, 63 years; 54% male), 12.2% experienced C5 palsy. On univariate analysis, C5 palsy was associated with foraminal diameter (P = 0.0005), spinal cord cross-sectional area (P = 0.11), number of levels undergoing laminectomy (P = 0.14), and clinical presentation of dropping objects (P = 0.07), hand clumsiness (P = 0.13), or paresthesias in the upper extremities (P = 0.08). Foraminal diameter (odds ratio, 0.31 per mm increase; 95% confidence interval, 0.16-0.60; P < 0.001) and patient report of gait disturbance (odds ratio, 0.53; 95% confidence interval, 0.33-0.85; P = 0.008) were the only significant predictors on multivariate analysis. A foraminal diameter <2 mm had 2-fold greater odds of postoperative C5 palsy. A receiver operating curve for the multivariate logistic model had an associated C-statistic of 0.7818. The absolute error of this model was 9.3% on internal validation., Conclusions: Foraminal stenosis most strongly predicted postoperative C5 palsy. A proof-of-concept model incorporating foramen size, as well as clinical complaints of paresthesias, hand clumsiness, and gait abnormality, successfully predicts the occurrence of postoperative palsy with an overall accuracy of 78%., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Occipitocervical congenital pathologies involving instability of the atlantoaxial joint and basilar invagination are challenging to treat owing to the complex anatomy involving neurovascular structures at the skull base and the high-risk nature of surgery close to the brainstem., Case Description: A patient presented with Alagille syndrome with multiple segmentation/fusion anomalies of the cervical spine and craniocervical junction, including fusion of the skull base and occipital condyles and partial assimilation of the C1 anterior ring and C2 dens. The head was anteriorly displaced, with C2 located immediately below the foramen magnum. There was significant kyphotic angulation due to nonunion of the base of the dens and the body of C2. The patient underwent occipitocervical osteotomies and occiput-C2 interfacet grafts for reduction of occipitocervical kyphosis along with foramen magnum decompression and occiput-C6 fusion. The patient had significant neurologic improvement and sustained improved craniocervical alignment on last follow-up., Conclusions: In patients with atlantoaxial instability with basilar invagination, posterior facet release, local distraction, and placement of cortical bone interbody grafts with occipitocervical fusion may be instrumental in reducing craniocervical kyphosis and compression by allowing anterior translation of the upper cervical spine relative to the skull. This method may be a safe and effective posterior-only approach for brainstem/spinal cord decompression for patients with complex craniocervical congenital malformations., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Background: Posterior atlantoaxial fusion is an important armamentarium for neurosurgeons to treat several pathologies involving the craniovertebral junction. Although the potential advantages of recombinant human bone morphogenetic protein-2 (rhBMP-2) are well documented in the lumbar spine, its indication for C1-C2 fusion has not been well characterized. In our institution, we apply rhBMP-2 to the C1-C2 joint either alone or with hydroxyapatite, locally harvested autograft chips, and/or morselized allogenic bone graft for selected cases-without conventional posterior structural bone graft. We report the clinical outcomes of the surgical technique to elucidate its feasibility., Methods: We performed a single-center, retrospective review of data from 2008 to 2016 and identified 69 patients who had undergone posterior atlantoaxial fusion with rhBMP-2. The clinical records of these patients were reviewed, and the baseline characteristics, operative data, and postoperative complications were collected and statistically analyzed., Results: The average age of the 69 patients was 60.8 ± 4.5 years, and 55.1% were women. With an average follow-up period of 21.1 ± 4.2 months, the C1-C2 fusion rate was 94.3% (65 of 69), and the average time to fusion was 11.4 ± 2.6 months (range, 5-23). The overall reoperation rate was 10.1% (7 of 69), with instrumentation failure in 7 patients (10.1%), adjacent segment disease in 2 (2.9%), and postoperative dysphagia and dyspnea in 2 patients (2.9%). No ectopic bone formation or soft tissue edema developed., Conclusions: Although retrospective and from a single center, our study has shown that rhBMP-2 usage at the C1-C2 joint without posterior structural bone grafting is a safe and reasonable surgical option., (Copyright © 2018 Elsevier Inc. All rights reserved.)

We developed a predictive model to describe risk factors for complications in cervical deformity surgeries. Cervical deformity (CD) surgical patients are growing in number, but remain under-studied in the literature. CD was defined as at least one of the following: C2-C7 Cobb >10°, CL >10°, cSVA >4 cm, CBVA >25°. Patient demographics and clinical data were assessed as risk factors for medical/surgical complications using multivariate regression models. 123 patients underwent CD surgery (60.6 yrs, 60.8% F). The most common complications were neurologic (24.4%), dysphagia (13.0%), cardiopulmonary (11.4%), infection (9.7%). 51 (41.5%) of patients experienced a medical complication and 73 (59.3%) had a surgical complication. An overall complication was predicted with high accuracy (AUC = 0.79) by the following combinations of factors: higher baseline EQ5D pain and lower baseline EQ5D anxiety/depression scores, and higher cervical and global SVA. A medical complication can be predicted by male gender, baseline mJOA score, and cervical SVA (AUC = 0.770). A surgical complication can be predicted by higher estimated blood loss, lower anxiety scores, and larger global SVA (AUC = 0.739). 64.2% of patients undergoing cervical deformity correction sustained any complication. While the most reliable predictor of the occurrence of a complication involved a cluster of risk factors, a radiographic baseline sagittal parameter of cervical SVA was the strongest isolated predictor for complications across categories. Although these findings are specific to a cervical population with moderate to severe deformities, collectively they can be utilized for pre-operative risk assessment and patient education., (Copyright © 2018. Published by Elsevier Ltd.)

Background: Cervical spine (C-spine) injuries cause significant morbidity and mortality among elderly patients. Although the population of older-adults ≥65 years in the United States is expanding, estimates of the burden and outcome of C-spine injury are lacking., Methods: The Nationwide Inpatient Sample 2001-2010 was analyzed. International Classification of Diseases, Ninth Revision, Clinical Modification codes identified patients with isolated C-spine fractures (ICF) and C-spine fractures with spinal cord injury (CSCI). Annual admission and mortality rates were calculated using U.S. Census data., Results: A total of 167,278 older adults were included. Median age was 81 years (interquartile range = 74-86). Most patients were female (54.9%), had Medicare coverage (77.6%), were treated in teaching hospitals (63.2%), and had falls as the leading injury mechanism (51.2%). ICF occurred in 91.3%, whereas CSCI occurred in 8.7% (P < 0.001). ICF was more common in ≥85-year-old patients and CSCI in 65- to 69-year-old patients (P < 0.001). The most common injured C-spine level in ICF was the C2 level (47.6%, P < 0.001) and in CSCI was C1-C4 level (4.5%, P < 0.001). Overall, 15.8% underwent C-spine surgery. Hospitalization rates increased from 26/100,000 in 2001 to 68/100,000 in 2010 (∼167% change, P < 0.001). Correspondingly, overall mortality increased from 3/100,000 in 2001 to 6/100,000 in 2010, P < 0.001. In-hospital mortality was 11.3%, was strongly associated with increasing age and CSCI (P < 0.001)., Conclusions: In summary, C-spine fractures among U.S. older adults constitute a significant health care burden. ICFs occur commonly, C2-vertebra fractures are most frequent, whereas CSCIs are linked to increased hospital-resource use and worse outcomes. The incidence of C-spine fractures and mortality more than doubled over the past decade; however, proportional in-hospital mortality is decreasing., (Copyright © 2018. Published by Elsevier Inc.)

Objective: To compare in-hospital complication rates in pediatric patients with atlantoaxial and subaxial injuries undergoing either external fixation or surgical fusion., Patients and Methods: Baseline and outcome data were obtained from the 2002-2011 Nationwide Inpatient Sample (NIS) for patients under the age of 18 with a diagnosis of cervical spine fracture without spinal cord injury or cervical spine subluxation. Patients who underwent external immobilization or internal fixation were included for analysis. Variables analyzed included length of stay, in-hospital mortality, discharge disposition, total hospital charges, and development of at least one in-hospital complication., Results: A total of 2878 pediatric patients with cervical spine injury were identified; 1462 patients (50.8%) with atlantoaxial (C1-2) injury and 1416 (49.2%) with subaxial (C3-7) injury. Among atlantoaxial injury patients, external fixation was associated with lower total charges ($73,786 vs. $98,158, p = .040) and a lower likelihood of developing at least one complication (1.9% vs. 6.8%, p = .029) compared to surgical fusion, and was a more common treatment for subluxation alone (16.4% vs. 2.6%, p < .001). Among subaxial injury patients, there were no significant differences in age (p = .262), length of stay (p = .196), occurrence of at least one complication (p = .334), or total charges (p = .142). Subaxial subluxation injuries alone were treated more often with surgical fusion (2.2% vs. 1.2%, p < .001)., Conclusion: Optimal treatment of patients with cervical injury may vary by location of injury. Our findings warrant further investigation into the difference in clinical outcomes between surgical and non-surgical management of atlantoaxial and subaxial injury., (Copyright © 2018. Published by Elsevier B.V.)

Objective: To determine the value of a novel adult cervical deformity frailty index (CD-FI) in preoperative risk stratification., Methods: We reviewed a prospective, multicenter database of adults with cervical spine deformity. We selected 40 variables to construct the CD-FI using a validated method. Patients were categorized as not frail (NF) (<0.2), frail (0.2-0.4), or severely frail (SF) (>0.4) according to CD-FI score. We performed multivariate logistic regression to determine the relationships between CD-FI score and incidence of complications, length of hospital stay, and discharge disposition., Results: Of 61 patients enrolled from 2009 to 2015 with at least 1 year of follow-up, the mean CD-FI score was 0.26 (range 0.25-0.59). Seventeen patients were categorized as NF, 34 as frail, and 10 as SF. The incidence of major complications increased with greater frailty, with a gamma correlation coefficient of 0.25 (asymptotic standard error, 0.22). The odds of having a major complication were greater for frail patients (odds ratio 4.4; 95% confidence interval 0.6-32) and SF patients (odds ratio 43; 95% confidence interval 2.7-684) compared with NF patients. Greater frailty was associated with a greater incidence of medical complications and had a gamma correlation coefficient of 0.30 (asymptotic standard error, 0.26). Surgical complications, discharge disposition, and length of hospital stay did not correlate significantly with frailty., Conclusions: Greater frailty was associated with greater risk of major complications for patients undergoing cervical spine deformity surgery. The CD-FI may be used to improve the accuracy of preoperative risk stratification and allow for adequate patient counseling., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background Context: Complication rates for adult cervical deformity are poorly characterized given the complexity and heterogeneity of cases., Purpose: To compare perioperative complication rates following adult cervical deformity corrective surgery between a prospective multicenter database for patients with cervical deformity (PCD) and the Nationwide Inpatient Sample (NIS)., Study Design/setting: Retrospective review of prospective databases., Patient Sample: A total of 11,501 adult patients with cervical deformity (11,379 patients from the NIS and 122 patients from the PCD database)., Outcome Measures: Perioperative medical and surgical complications., Methods: The NIS was queried (2001-2013) for cervical deformity discharges for patients ≥18 years undergoing cervical fusions using International Classification of Disease, Ninth Revision (ICD-9) coding. Patients ≥18 years from the PCD database (2013-2015) were selected. Equivalent complications were identified and rates were compared. Bonferroni correction (p<.004) was used for Pearson chi-square. Binary logistic regression was used to evaluate differences in complication rates between databases., Results: A total of 11,379 patients from the NIS database and 122 patiens from the PCD database were identified. Patients from the PCD database were older (62.49 vs. 55.15, p<.001) but displayed similar gender distribution. Intraoperative complication rate was higher in the PCD (39.3%) group than in the NIS (9.2%, p<.001) database. The PCD database had an increased risk of reporting overall complications than the NIS (odds ratio: 2.81, confidence interval: 1.81-4.38). Only device-related complications were greater in the NIS (7.1% vs. 1.1%, p=.007). Patients from the PCD database displayed higher rates of the following complications: peripheral vascular (0.8% vs. 0.1%, p=.001), gastrointestinal (GI) (2.5% vs. 0.2%, p<.001), infection (8.2% vs. 0.5%, p<.001), dural tear (4.1% vs. 0.6%, p<.001), and dysphagia (9.8% vs. 1.9%, p<.001). Genitourinary, wound, and deep veinthrombosis (DVT) complications were similar between databases (p>.004). Based on surgicalapproach, the PCD reported higher GI and neurologic complication rates for combined anterior-posterior procedures (p<.001). For posterior-only procedures, the NIS had more device-related complications (12.4% vs. 0.1%, p=.003), whereas PCD had more infections (9.3% vs. 0.7%, p<.001)., Conclusions: Analysis of the surgeon-maintained cervical database revealed higher overall and individual complication rates and higher data granularity. The nationwide database may underestimate complications of patients with adult cervical deformity (ACD) particularly in regard to perioperative surgical details owing to coding and deformity generalizations. The surgeon-maintained database captures the surgical details, but may underestimate some medical complications., (Copyright © 2017 Elsevier Inc. All rights reserved.)

The relationship between smoking and the risk of postoperative complications among anterior cervical discectomy and fusion (ACDF) patients remains uncertain. We compared the postoperative complication rates following ACDF surgery among non-smokers, current smokers, and ever-smokers. Baseline and outcome data were obtained from the 2005- to 2014 American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database for patients over the age of 18 who underwent non-emergent ACDF surgery. Information on current smoking and ever-smoking status was extracted. Outcomes included development of at least one complication, development of a major complication, in-hospital mortality, and length of stay. ACDF patients were either current smokers (7847, 30.3%) or not current smokers (18,022, 69.7%); 33.0% of all patients (n=8542) had ever smoked. Current smoking status was not associated with increased odds of any one complication (P=0.584) or any major complication (P=0.138). In addition, using the number of pack-years as the primary independent variable, multivariate logistic regression analysis revealed that the number of pack-years was not significantly associated with greater odds of developing any one complication (P=0.276) or any major complication (P=0.334). However, ever-smoker status did present significantly higher odds of any major complication (OR, 1.333; 95% CI 1.007-1.764; P=0.044) than for non-smokers. These results suggest that any patient with a prior smoking history should be considered a higher risk surgical candidate when attempting ACDF., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

OBJECTIVE The goal of this study was to compare 30-day readmission and reoperation rates after single-level anterior cervical discectomy and fusion (ACDF) versus those after cervical disc replacement (CDR). METHODS The authors used the 2013-2014 American College of Surgeons National Surgical Quality Improvement Program database. Included were adult patients who underwent first-time single-level ACDF or CDR for cervical spondylosis or disc herniation. Primary outcome measures were readmission and/or reoperation within 30 days of the original surgery. Logistic regression analysis was used to assess the independent effect of the procedure (ACDF or CDR) on outcome, and results are presented as odds ratios with 95% confidence intervals. RESULTS A total of 6077 patients met the inclusion criteria; 5590 (92.0%) patients underwent single-level ACDF, and 487 (8.0%) patients underwent CDR. The readmission rates were 2.6% for ACDF and 0.4% for CDR (p = 0.003). When stratified according to age groups, only patients between the ages of 41 and 60 years who underwent ACDF had a significantly higher readmission rate than those who underwent CDR (2.5% vs 0.7%, respectively; p = 0.028). After controlling for patient age, sex, body mass index, smoking status, history of chronic obstructive pulmonary disease (COPD), diabetes, hypertension, steroid use, and American Society of Anesthesiologists (ASA) class, patients who underwent CDR were significantly less likely to undergo readmission within 30 days than patients who underwent ACDF (OR 0.23 [95% CI 0.06-0.95]; p = 0.041). Patients with a history of COPD (OR 1.97 [95% CI 1.08-3.57]; p = 0.026) or hypertension (OR 1.62 [95% CI 1.10-2.38]; p = 0.013) and those at ASA Class IV (OR 14.6 [95% CI 1.69-125.75]; p = 0.015) were significantly more likely to require readmission within 30 days. The reoperation rates were 1.2% for ACDF and 0.4% for CDR (p = 0.086), and multivariate analysis revealed that CDR was not associated with lower odds of reoperation (OR 0.60 [95% CI 0.14-2.55]; p = 0.492). However, increasing age was associated with a higher risk (OR 1.02 [95% CI 1.00-1.05]; p = 0.031) of reoperation; a 2% increase in risk per year of age was found. CONCLUSIONS Patients who underwent single-level ACDF had a higher readmission rate than those who underwent single-level CDR in this study. When stratified according to age, this effect was seen only in the 41- to 60-year age group. No significant difference in the 30-day single-level ACDF and single-level CDR reoperation rates was found. Although patients in the ACDF group were older and sicker, other unmeasured covariates might have accounted for the increased rate of readmission in this group, and further investigation is encouraged.

Objective: We sought to investigate the postoperative morbidity and mortality rate of patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) undergoing elective anterior cervical fusion (ACF)., Methods: The Nationwide Inpatient Sample database from 2002-2011 was used to identify adult patients who underwent elective ACF for degenerative spine disease. Major complication rates and in-hospital mortality were compared among 3 groups-no kidney disease, CKD, and ESRD (dialysis dependent). A multiple logistic regression analysis was conducted to assess the independent effect of CKD and ESRD on outcome., Results: There were 164,097 patients who met inclusion criteria. Among these, 1047 had CKD (0.64%) and 270 had ESRD (0.16%). After multiple logistic regression analysis, patients with CKD (odds ratio [OR] 1.51; 95% confidence interval [CI], 1.13-2.01; P = 0.005) and ESRD (OR 1.96; 95% CI, 1.20-3.21; P = 0.007) were significantly more likely to incur a postoperative complication when compared with patients without kidney disease (the reference group). Compared with patients without kidney disease, patients with CKD did not have higher odds of postoperative mortality (OR 2.25; 95% CI, 0.83-6.06; P = 0.108). However, in-hospital mortality was 15 times higher for patients with ESRD compared with patients without kidney disease (OR 15.2; 95% CI, 5.67-40.88; P < 0.001)., Conclusion: Chronic and end-stage renal disease may significantly increase the risk of postoperative morbidity and mortality after ACF. Future research into preoperative optimization of these patients and on the potential benefits of undergoing surgery until after renal transplantation is warranted., (Copyright © 2016. Published by Elsevier Inc.)

Lipomyelomeningocele (LMM) as a cause of tethered cord syndrome (TCS) commonly presents in childhood in the lumbosacral spine. Patients frequently present with cutaneous manifestations, progressive neurological deterioration, bladder dysfunction, and intractable pain. Early surgical intervention with untethering is recommended for symptomatic patients. We report an unusual case of a woman who presented with a subcutaneous lump, pain, and neurological decline found to have a cervicothoracic LMM. The patient underwent laminectomy and subtotal resection of the mass; seventeen years later she was confined to a wheelchair with severe neurological decline ultimately requiring three additional attempts at surgical excision and repair. This case emphasizes the need for early recognition of and intervention in adult patients with LMM., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Patients with end stage renal disease on hemodialysis may present with destructive spondyloarthropathy of the spine, most commonly in the subaxial cervical and lumbar spine, often with severe stenosis and instability. However, surgical management of these patients is challenging due to a high pseudarthrosis rate, poor bone quality, and medical frailty. We present a 49-year-old man on hemodialysis who presented with C4-C5 vertebral body destruction and a focal kyphotic deformity with myelopathy. The patient underwent a 360 degree decompression and reconstructive procedure that resulted in posterior instrumentation failure. Several salvage techniques were used in order to adequately stabilize the spine while preserving the patient's remaining cervical motion., (Published by Elsevier Ltd.)

OBJECTIVE The purpose of this study was to report the long-term clinical outcomes following 3- and 4-level anterior cervical discectomy and fusion (ACDF). METHODS A retrospective review of all adult neurosurgical patients undergoing elective ACDF for degenerative disease at a single institution between 1996 and 2013 was performed. Patients who underwent first-time 3- or 4-level ACDF were included; patients with previous cervical spine surgery, those undergoing anterior/posterior approaches, and those with corpectomy were excluded. Outcome measures included perioperative complication rates, fusion rates, need for revision surgery, Nurick Scores, Odom's criteria, symptom resolution, neck visual analog scale (VAS) pain score, and persistent narcotics usage. RESULTS Seventy-one patients who underwent 3-level ACDF and 26 patients who underwent 4-level ACDF were identified and followed for an average of 7.6 ± 4.2 years. There was 1 case (3.9%) of deep wound infection in the 4-level group and 1 case in the 3-level group (1.4%; p = 0.454). Postoperatively, 31% of patients in the 4-level group complained of dysphagia, compared with 12.7% in the 3-level group (p = 0.038). The fusion rate was 84.6% after 4-level ACDF and 94.4% after 3-level ACDF (p = 0.122). At last follow-up, a significantly higher proportion of patients in the 4-level group continued to have axial neck pain (53.8%) than in the 3-level group (31%; p = 0.039); the daily oral morphine equivalent dose was significantly higher in the 4-level group (143 ± 97 mg/day) than in the 3-level group (25 ± 10 mg/day; p = 0.030). Outcomes based on Odom's criteria were also different between cohorts (p = 0.044), with a significantly lower proportion of patients in the 4-level ACDF group experiencing an excellent/good outcome. CONCLUSIONS In this study, patients who underwent 4-level ACDF had significantly higher rates of dysphagia, postoperative neck pain, and postoperative narcotic usage when compared with patients who underwent 3-level ACDF. Pseudarthrosis and deep wound infection rates were also higher in the 4-level group, although this did not reach statistical significance. Additionally, a smaller proportion of patients achieved a good/excellent outcome in the 4-level group than in the 3-level group. These findings suggest a significant increase of perioperative morbidity and worsened outcomes for patients who undergo 4- versus 3-level ACDF.

Background: Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure. Cerebrospinal fluid (CSF) leaks, although uncommon, may occur and can be a potentially serious complication. Little is known regarding the fusion rate after durotomy in ACDF. This study sought to investigate the clinical outcomes and fusion rates of patients with CSF leak after ACDF., Methods: In this single-institution retrospective review, 14 patients who experienced CSF leak after ACDF between 1995 and September 2014 were identified., Results: The median follow-up was 13.1 months. The diagnoses included spondylosis/degenerative disc disease (n = 10), disc herniation with radiculopathy (n = 3), and kyphotic deformity (n = 1). Of ACDFs, 7 were 1-level, 5 were 2-level, and 2 were 3-level procedures. The posterior longitudinal ligament was intentionally opened in all cases, and the microscope was used in 9 cases. Durotomy was discovered intraoperatively in all cases and was generally repaired with a combination of fibrin glue and synthetic dural replacement. Lumbar drainage was used in 5 patients, and 3 patients reported orthostatic headaches, which resolved within 1 month. Two patients reported hoarseness, and 8 patients reported dysphagia; all cases were transient. Follow-up imaging for fusion assessment was available for 12 patients, and a 100% fusion rate was achieved with no postoperative infections., Conclusions: ACDFs with CSF leak had a 100% fusion rate in this series, with generally excellent clinical outcomes, although it is difficult to conclude definitively that there is no effect on fusion rates because of the small sample size. However, given the relative rarity of this complication, this study provides important data in the clinical literature regarding outcomes after CSF leak in ACDFs., (Published by Elsevier Inc.)

Pneumocephalus is a collection of air within in the intracranial cavity, most commonly seen following traumatic injury or cranial surgeries. Esophageal injury and cerebrospinal fluid (CSF) leak are rare complications that may occur following anterior cervical discectomy and fusion (ACDF). We present a novel case of pneumocephalus arising from unrestricted leakage of CSF via coincident esophageal injury and durotomy in a patient who underwent an ACDF after trauma. A 21-year-old man presented to an outside hospital with C5/C6 subluxation, complete spinal cord injury, and quadriplegia from a motor vehicle accident. He underwent an ACDF, during which a CSF leak was observed. He was then transferred to our institution for rehabilitation and tracheostomy placement 1 week after the ACDF surgery. Following the tracheostomy, the patient developed intractable fevers and nonspecific symptoms. A CT scan demonstrated frontal pneumocephalus without mass effect. Air was found in the retropharyngeal space. There were no accumulations of CSF in the neck. Extravasation of contrast around instrumentation at C5/C6 on a cine esophagogram demonstrated an esophageal perforation at that level. Pneumocephalus may form when large volumes of CSF escape from the intracranial space and air is drawn into the space by the negative pressure. In this unusual case, the esophageal perforation promoted the formation of the pneumocephalus. Treatment included closure of both defects, disrupting the suspected communication between the intracranial space and the esophagus., (Published by Elsevier Ltd.)

Object: Recently, aggressive surgical techniques and a push toward en bloc resections of certain tumors have resulted in a need for creative spinal column reconstruction. Iatrogenic instability following these resections requires a thoughtful approach to adequately transfer load-bearing forces from the skull and upper cervical spine to the subaxial spine., Methods: The authors present a series of 7 cases in which lateral mass reconstruction with a cage or fibular strut graft was used to provide load-bearing support, including 1 case of bilateral cage placement., Results: The authors discuss the surgical nuances of en bloc resection of high cervical tumors and explain their technique for lateral mass cage placement. Additionally, they provide their rationale for the use of these constructs throughout the craniocervical junction and subaxial spine., Conclusions: Lateral mass reconstruction provides a potential alternative or adjuvant method of restoring the load-bearing capabilities of the cervical spine.

Object: This study was undertaken to compare surgical outcomes between patients with atlantoaxial versus subaxial cervical synovial cysts (CSCs) and to compare outcomes between patients who underwent decompression alone versus decompression and fusion for the treatment of CSCs., Methods: The authors present a series of 17 cases involving patients treated at their institution and report the surgical outcomes. Due to the rarity of CSCs, a meta-analysis was conducted, and results of the literature search were combined with the case series to enhance the power of the study., Results: Seventeen patients underwent surgical treatment for CSCs at our institution: 3 patients (17.6%) had atlantoaxial cysts and 14 (82.3%) had subaxial cysts. Of the 17 patients, 16 underwent a decompression and fusion; most patients experienced symptom resolution at last follow-up, and there were no cyst recurrences. A total of 54 articles (including the current series) and 101 patients were included in the meta-analysis. The mean age at presentation was 64 ± 13.9 years, and the most common symptoms were motor and sensory deficits. Forty-one patients (40.6%) presented with atlantoaxial cysts, and 60 (59.4%) with subaxial cysts. There were no significant differences between groups in terms of presenting symptoms, Nurick scores, surgical treatment, or surgical outcomes. Fifty-two patients (51.4%) underwent surgical decompression without fusion, while 49 patients (48.6%) underwent fusion. The preoperative Nurick scores were significantly lower in the fused group (p = 0.001), with an average score of 1.32 compared with 2.75 in the nonfused group. After a mean follow-up of 16.5 months, a difference of means analysis between final and preoperative Nurick scores revealed that patients who received a decompression alone improved on average 1.66 points (95% CI 1.03-2.29) compared with 0.8 points (95% CI 0.23-1.39) in the fused group (p = 0.004). However, there was no statistically significant difference in symptom resolution between the groups, and the rate of cyst recurrence was found to be 0%., Conclusions: In this study, patients with CSCs had similar outcomes regardless of cyst location and regardless of whether they underwent decompression only or fusion. In the authors' institutional experience, 16 of 17 patients underwent fusion due to underlying spinal instability. While there were no reports of cyst recurrence in their series or in the literature in patients who only received decompression, this is likely due to the limited follow-up time available for the study population. Longer follow-up and prospective and biomechanical studies are needed to corroborate these findings.

Object: The authors conducted a study to investigate the rate and timing of reoperation due to symptom recurrence after unilateral posterior cervical foraminotomy (PCF)., Methods: The authors retrospectively reviewed demographic, surgical, and clinical data from 151 patients who underwent unilateral PCF at their institution with an average follow-up of 4.15 years. The main outcome variables were reoperation rate, time to reoperation, and short- and long-term radiculopathy improvement rates. Kaplan-Meier analyses were conducted to assess risk of reoperation and recurrence of radiculopathy over time., Results: After index PCF in 151 patients, the overall reoperation rate was 9.9% (15 patients). The average time until reoperation was 2.4 years, and the average last follow-up examination was 4.15 years after the first surgery. Patients who presented with preoperative neck pain in addition to radiculopathy had a higher risk for reoperation and a shorter time to reoperation. The majority of patients who underwent a reoperation had an anterior cervical discectomy and fusion (80%). A smaller number of patients had reoperation that included a repeat PCF (6.7%) or laminectomy with posterior cervical fusion (13.3%). The rate of same-level reoperation (6.6%, 10 patients) was significantly higher (p = 0.05) when compared with adjacent-segment (1.3%, 2 patients) or distant-segment (1.9%, 3 patients) reoperation. At last follow-up, the overall rate of improvement in radiculopathy was 85%, with the majority of patients (91.4%) experiencing resolution as early as 1 month after index surgery. Following the subgroup that experienced initial symptom improvement, 16.1% of these patients experienced radiculopathy recurrence an average of 7.3 years after the initial operation. While the reoperation rate for the overall cohort in this series was 9.9%, patients with follow-up periods longer than 2 years had a reoperation rate of 18.3%. Moreover, patients with more than 10 years of follow-up had a reoperation rate of 24.3%., Conclusions: PCF is a procedure performed to address nerve root compression in the cervical spine. The authors evaluated 151 patients who underwent unilateral PCF and found a reoperation rate of 9.9% at an average of 2.4 years after the initial surgery (6.6% at same level, 3.3% elsewhere). The reoperation rates reached 18.3% and 24.3% in patients with follow-up periods longer than 2 and 10 years, respectively. The authors' analysis revealed that patients with no preoperative neck pain had the lowest rates of revision surgery after PCF.

Objective: The objective of this study is to evaluate the incidence and prognostic factors of breach rates following the placement of C2 pedicle screws using the anatomic, freehand technique., Methods: We retrospectively reviewed the medical records of all patients who underwent C2 transpedicular instrumentation over six years at a single institution. All intraoperative, image-guided techniques were excluded. Breaches were ascertained from immediate postoperative CT images. All images were analyzed by three independent reviewers. The screw length was correlated with (1) the breach rate and (2) the breach severity. Severity of the breached screws reflects the screw circumference (0-360°) perforating the pedicle wall (Grade 1-Grade 4)., Results: Of the 341 C2 pedicle screws inserted in 181 patients, the average screw length was 22.93±3.7mm. The average distance from the foramen transversarium to the screw insertion point was 13.17±2.63mm. The distance from the medial rim of the pedicle to the dura of spinal cord was 3.53±1.57mm. Of the 341 screws, the overall breach rate was 17.3% (n=59). Of the 59 breaches, 89.83% of screws (n=53) breaching the spinal canal was statistically significantly higher than the 10.17% of screws (n=6) breaching the foramen transversarium (p<0.001). Moreover, 27 (45.8%) were Grade 1, 16 (27.1%) Grade 2, 6 (10.2%) Grade 3, and 10 (16.9%) Grade 4. None of the C2 breaches resulted in neurological sequela. No association was found between breach rate and gender, race or age. While the average screw length was 22.93±3.7mm [12-34mm], screw length did not predict a cortical violation (p=0.4) or severity of the breach (p=0.42) in a multiple regression model., Conclusions: In this cohort study on the anatomic freehand placement of C2 pedicle screws, the breach rate was 17.3%. Lateral breaches were more common than medial breaches. Screw length was not statistically correlated with cortical violation or severity of breach. Therefore, screw length is not a prognostic factor for C2 pedicle screw misplacement., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Object: Chordomas involving the mobile spine are ideally managed via en bloc resection with reconstruction to optimize local control and possibly offer cure. In the cervical spine, local anatomy poses unique challenges, limiting the feasibility of aggressive resection. The authors present a multi-institutional series of 16 cases of cervical chordomas removed en bloc. Particular attention was paid to clinical outcome, complications, and recurrence. In addition, outcomes were assessed according to position of tumor at the C1-2 level versus the subaxial (SA) spine (C3-7)., Methods: The authors reviewed cases involving patients who underwent en bloc resection of cervical chordoma at 4 large spine centers. Patients were included if the lesion epicenter involved the C-1 to C-7 vertebral bodies. Demographic data and details of surgery, follow-up course, exposure to adjuvant therapy, and complications were obtained. Outcome was correlated with presence of tumor in C1-2 versus subaxial spine via a Student t-test., Results: Sixteen patients were identified (mean age at presentation 55 ± 14 years). Seven cases (44%) cases involved C1-2, and 16 involved the subaxial spine. Median survival did not differ significantly different between the C1-2 (72 months) and SA (60 months) groups (p = 0.65). A combined (staged anteroposterior) approach was used in 81% of the cases. Use of the combined approach was significantly more common in treatment of subaxial than C1-2 tumors (100% vs 57%, p = 0.04). En bloc resection was attempted via an anterior approach in 6% of cases (C1-2: 14.3%; SA: 0%; p = 0.17) and a posterior approach in 13% of cases (C1-2: 29%; SA: 0%; p = 0.09). The most commonly reported margin classification was marginal (56% of cases), followed by violated (25%) and wide (19%). En bloc excision of subaxial tumors was significantly more likely to result in marginal margins than excision of C1-2 tumors (C1-2: 29%; SA: 78%; p = 0.03). C1-2 tumors were associated with significantly higher rates of postoperative complications (C1-2: 71%; SA: 22%; p = 0.03). Both local and distant tumor recurrence was greatest for C1-2 tumors (local C1-2: 29%; local SA: 11%; distant C1-2: 14%; distant SA: 0%). Statistical analysis of tumor recurrence based on tumor location was not possible due to the small number of cases. There was no between-groups difference in exposure to postoperative adjuvant radiotherapy. There was no difference in median survival between groups receiving proton beam radiotherapy or intensity-modulated radiotherapy versus no radiation therapy (p = 0.8)., Conclusions: Compared with en bloc resection of chordomas involving the subaxial cervical spine, en bloc resection of chordomas involving the upper cervical spine (C1-2) is associated with poorer outcomes, such as less favorable margins, higher rates of complications, and increased tumor recurrence. Data from this cohort do not support a statistically significant difference in survival for patients with C1-2 versus subaxial disease, but larger studies are needed to further study survival differences.

Study Design: Retrospective clinical study., Objective: To study the long-term effects of repeat cervical fusion after development of adjacent segment disease (ASD)., Summary of Background Data: ASD is a well-recognized development after anterior cervical discectomy and fusion (ACDF). Although there are data on the development of ASD after ACDF, the incidence of ASD after repeat ACDF has not been well established., Methods: We collected 888 consecutive patients who underwent ACDF for cervical degenerative disease during a 20-year period at a single institution. Patients were followed for an average of 94.0 ± 78.1 months after the first ACDF., Results: Of the 888 patients who underwent ACDF, 108 patients developed ASD, necessitating a second cervical fusion. Among these 108 patients, 27 patients later developed recurrent ASD, requiring a third cervical fusion. Thus, in this series, the incidence of ASD after ACDF is 12.2%, statistically increasing to 25% after a second cervical fusion (P = 0.0002). Notably, ASD occurred 47.0 ± 44.9 months after the first ACDF and statistically decreased to 30.3 ± 24.9 months after a second cervical fusion (P = 0.01). Of the 77 patients who underwent a second cervical fusion via an anterior approach, 23 developed recurrent ASD requiring a third cervical fusion. In contrast, of the 31 patients who had a posteriorly approached second cervical fusion, only 4 developed recurrent ASD requiring a third cervical fusion., Conclusion: We present a cohort of patients undergoing multiple sequential operations due to ASD during a 20-year period. In this series of 888 patients, the incidence of ASD development is lowest after the first ACDF. Patients who undergo a second cervical fusion develop ASD at both higher and faster rates. Moreover, patients who had a second cervical fusion via an anterior approach had a higher chance of developing recurrent ASD versus patients who had a posterior approach., Level of Evidence: 3.

The bony spine is overall the third most common site for distant cancer metastasis, with the cervical spine involved in approximately 8 to 20% of metastatic spine disease cases. Diagnosis and management of metastatic spine disease requires disease categorization into the compartment involved, pathology of the lesion, and anatomic region involved. The diagnostic approach should commence with careful physical examination, and the workup should include plain radiographs, magnetic resonance imaging, computed tomography, and bone scintigraphy. Management ranges from palliative nonoperative to aggressive surgical treatment. Optimal management requires proper patient selection to individualize the most appropriate treatment modality., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Study Design: Retrospective case series of five consecutive patients., Objective: To determine the oncological outcomes and morbidity rates after en bloc excisions of cervical chordomas., Summary of Background Data: Studies have demonstrated that en bloc surgical excision of chordoma with negative margins results in improved local disease control and survival compared with intralesional resections. Chordomas arising from the cervical spine are rare and they present unique challenges for en bloc tumor excision. We present a series of five consecutive cases of cervical chordoma managed with en bloc tumor excision, which represents one of the largest surgical experiences of cervical chordomas reported to date., Methods: A retrospective review of our institutional spine tumor database identified five consecutive patients who underwent en bloc tumor excision for cervical spine chordoma from 2000 to 2007. We analyze their surgical margins, perioperative complications, tumor recurrence rate, and survival., Results: Our review demonstrated that dysphagia and cervicalgia were the most common presenting symptoms for cervical chordoma. The mean age of diagnosis in this cohort was 52.4 years and our mean follow-up is 54.7 months. All five patients required multistage procedures to achieve en bloc tumor excision. Independent analysis of the surgical margins by the pathologists revealed that marginal en bloc excisions were achieved in all five patients. Our 30-day perioperative complication was significant for one case of transient radiculopathy with paresis and one wound infection. Other long-term complications included three cases with pseudoarthrosis with instrumentation failures requiring surgical revisions. There were no neurological or cerebrovascular complications. The mean disease-free survival after en bloc spondylectomy for cervical chordoma was 84.2 months in this cohort., Conclusion: En bloc excision of chordoma, whether wide or marginal, is the most ideal for treatment to prolong disease-free survival. En bloc excisions of chordomas in the cervical spine are technically complex procedures but can be performed with acceptable safety and perioperative morbidity.

Object: The aim of this study was to conduct the first in vitro biomechanical comparison of immediate and postcyclical rigidities of C-7 lateral mass versus C-7 pedicle screws in posterior C4-7 constructs., Methods: Ten human cadaveric spines were treated with C4-6 lateral mass screw and C-7 lateral mass (5 specimens) versus pedicle (5 specimens) screw fixation. Spines were potted in polymethylmethacrylate bone cement and placed on a materials testing machine. Rotation about the axis of bending was measured using passive retroreflective markers and infrared motion capture cameras. The motion of C-4 relative to C-7 in flexion-extension and lateral bending was assessed uninstrumented, immediately after instrumentation, and following 40,000 cycles of 4 Nm of flexion-extension and lateral bending moments at 1 Hz. The effect of instrumentation and cyclical loading on rotational motion across C4-7 was analyzed for significance., Results: Preinstrumented spines for the 2 cohorts were comparable in bone mineral density and range of motion in both flexion-extension (p = 0.33) and lateral bending (p = 0.16). Lateral mass and pedicle screw constructs significantly reduced motion during flexion-extension (11.3°-0.26° for lateral mass screws, p = 0.002; 10.51°-0.30° for pedicle screws, p = 0.008) and lateral bending (7.38°-0.27° for lateral mass screws, p = 0.003; 11.65°-0.49° for pedicle screws, p = 0.03). After cyclical loading in both cohorts, rotational motion over C4-7 was increased during flexion-extension (0.26°-0.68° for lateral mass screws; 0.30°-1.31° for pedicle screws) and lateral bending (0.27°-0.39° and 0.49°-0.80°, respectively), although the increase was not statistically significant (p > 0.05). There was no statistical difference in postcyclical flexion-extension (p = 0.20) and lateral bending (0.10) between lateral mass and pedicle screws., Conclusions: Both C-7 lateral mass and C-7 pedicle screws allow equally rigid fixation of subaxial lateral mass constructs ending at C-7. Immediately and within a simulated 6-week postfixation period, C-7 lateral mass screws may be as effective as C-7 pedicle screws in biomechanically stabilizing long subaxial lateral mass constructs.

Object: Thoracic pedicle screw instrumentation is often indicated in the treatment of trauma, deformity, degenerative disease, and oncological processes. Although classic teaching for cervical spine constructs is to bridge the cervicothoracic junction (CTJ) when instrumenting in the lower cervical region, the indications for extending thoracic constructs into the cervical spine remain unclear. The goal of this study was to determine the role of ligamentous and facet capsule (FC) structures at the CTJ as they relate to stability above thoracic pedicle screw constructs., Methods: A 6-degree-of-freedom spine simulator was used to test multidirectional range of motion (ROM) in 8 human cadaveric specimens at the C7–T1 segment. Flexion-extension, lateral bending, and axial rotation at the CTJ were tested in the intact condition, followed by T1–6 pedicle screw fixation to create a long lever arm inferior to the C7–T1 level. Multidirectional flexibility testing of the T1–6 pedicle screw construct was then sequentially performed after sectioning the C7–T1 supraspinous ligament/interspinous ligament (SSL/ISL) complex, followed by unilateral and bilateral FC disruption at C7–T1. Finally, each specimen was reconstructed using C5–T6 instrumented fixation and ROM testing at the CTJ performed as previously described., Results: Whereas the application of a long-segment thoracic construct stopping at T-1 did not significantly increase flexion-extension peak total ROM at the supra-adjacent level, sectioning the SSL/ISL significantly increased flexibility at C7–T1, producing 35% more motion than in the intact condition (p < 0.05). Subsequent FC sectioning had little additional effect on ROM in flexion-extension. Surprisingly, the application of thoracic instrumentation had a stabilizing effect on the supra-adjacent C7–T1 segment in axial rotation, leading to a decrease in peak total ROM to 83% of the intact condition (p < 0.05). This is presumably due to interaction between the T-1 screw heads and titanium rods with the C7–T1 facet joints, thereby limiting axial rotation. Incremental destabilization served only to restore peak total ROM near the intact condition for this loading mode. In lateral bending, the application of thoracic instrumentation stopping at T-1, as well as SSL/ISL and FC disruption, demonstrated trends toward increased supraadjacent ROM; however, these trends did not reach statistical significance (p > 0.05)., Conclusions: When stopping thoracic constructs at T-1, care should be taken to preserve the SSL/ISL complex to avoid destabilization of the supra-adjacent CTJ, which may manifest clinically as proximal-junction kyphosis. In an analogous fashion, if a T-1 laminectomy is required for neural decompression or surgical access, consideration should be given to extending instrumentation into the cervical spine. Facet capsule disruption, as might be encountered during T-1 pedicle screw placement, may not be an acutely destabilizing event, due to the interaction of the C7–T1 facet joints with T-1 instrumentation.

Objective: The indications for treating cervical spondylotic myelopathy (CSM) with laminectomy and instrumented fusion remain ill-defined. Cervical laminectomy without instrumented fusion has been associated with suboptimal outcomes, particularly in the setting of cervical kyphosis. This work's purpose is to retrospectively review our experience in patients who underwent laminectomy with instrumented fusion for CSM and to assess the neurological and radiological outcomes of patients treated with this technique., Methods: Fifty-four consecutive patients underwent multilevel laminectomy and instrumented fusion for CSM. The indications were patients with (1) cervical stenosis > or = 3 spinal segments and (2) absence of a cervical kyphosis or (3) patients older than 65 years with significant medical comorbidities. Nurick myelopathy grades and cervical radiographs were obtained preoperatively and at 3, 6, 12 and 24 months post-operatively. Perioperative complications, radiographic and clinical outcomes were assessed and reported in this paper., Results: Forty-four (81%) of patients showed improvement in Nurick grade after surgery by a mean of 17 months. Ten patients (19%) demonstrated stable but unimproved myelopathy. Increasing pre-operative Nurick grade was associated with an improved post-operative outcome (p<0.02). Increasing duration of pre-operative myelopathy was associated with a decreased likelihood of myelopathy improvement (p<0.001)., Discussion: Multilevel cervical laminectomy with instrumented fusion for patients with CSM resulted in an improvement in myelopathy in the majority of cases. Efficacy was similar for patients who may not have tolerated an anterior decompression, such as elderly patients with significant medical comorbidities. Hardware-related complication rates were relatively low.

Chordomas are relatively rare tumors of bone. These primary malignant lesions occur throughout the spinal column and often show advanced growth at the time of diagnosis. Because such tumors are minimally responsive to radiation and chemotherapy, surgical resection is the mainstay of treatment. Patient survival and local control are associated with the ability to achieve wide surgical margins during excision. However, surgical morbidity may be substantial given the propensity for chordomas to abut or surround neural, vascular, and visceral structures. Thus, early recognition is essential, and treatment by a multidisciplinary team is ideal.