Complement-dependent neuroinflammation in spinal cord injury: from pathology to therapeutic implications.

ABSTRACT: Spinal cord injury remains a major cause of disability in young adults, and beyond acute decompression and rehabilitation, there are no pharmacological treatments to limit the progression of injury and optimize recovery in this population. Following the thorough investigation of the complement system in triggering and propagating cerebral neuroinflammation, a similar role for complement in spinal neuroinflammation is a focus of ongoing research. In this work, we survey the current literature investigating the role of complement in spinal cord injury including the sources of complement proteins, triggers of complement activation, and role of effector functions in the pathology. We study relevant data demonstrating the different triggers of complement activation after spinal cord injury including direct binding to cellular debris, and or activation via antibody binding to damage-associated molecular patterns. Several effector functions of complement have been implicated in spinal cord injury, and we critically evaluate recent studies on the dual role of complement anaphylatoxins in spinal cord injury while emphasizing the lack of pathophysiological understanding of the role of opsonins in spinal cord injury. Following this pathophysiological review, we systematically review the different translational approaches used in preclinical models of spinal cord injury and discuss the challenges for future translation into human subjects. This review emphasizes the need for future studies to dissect the roles of different complement pathways in the pathology of spinal cord injury, to evaluate the phases of involvement of opsonins and anaphylatoxins, and to study the role of complement in white matter degeneration and regeneration using translational strategies to supplement genetic models.

A case of myxopapillary ependymoma with predominant giant cell morphology: A rare entity with comprehensive genomic profiling and review of literature.

In the evolving landscape of ependymoma classification, which integrates histological, molecular, and anatomical context, we detail a rare case divergent from the usual histopathological spectrum. We present the case of a 37-year-old man with symptomatic spinal cord compression at the L3-L4 level. Neuroradiological evaluation revealed an intradural, encapsulated mass. Histologically, the tumor displayed atypical features: bizarre pleomorphic giant cells, intranuclear inclusions, mitotic activity, and a profusion of eosinophilic cytoplasm with hyalinized vessels, deviating from the characteristic perivascular pseudorosettes or myxopapillary patterns. Immunohistochemical staining bolstered this divergence, marking the tumor cells positive for glial fibrillary acidic protein and epithelial membrane antigen with a characteristic ring-like pattern, and CD99 but negative for Olig-2. These markers, alongside methylation profiling, facilitated its classification as a myxopapillary ependymoma (MPE), despite the atypical histologic features. This profile underscores the necessity of a multifaceted diagnostic process, especially when histological presentation is uncommon, confirming the critical role of immunohistochemistry and molecular diagnostics in classifying morphologically ambiguous ependymomas and exemplifying the histological diversity within MPEs.

Comparing Cortical Bone Trajectory and Traditional Pedicle Screws in Transforaminal Lumbar Interbody Fusion: A Retrospective Cohort Study of One-Year Outcomes.

INTRODUCTION: This is a retrospective study of consecutive patients undergoing transforaminal lumbar interbody fusion (TLIF) at a single institution. The objective of this study was to compare the long-term results associated with cortical bone trajectory (CBT) and traditional pedicle screw (TPS) via posterolateral approach in TLIF. METHODS: Consecutive patients treated from November 2014 to March 2019 were included in the CBT TLIF group, while consecutive patients treated from October 2010 to August 2017 were included in the TPS TLIF group. Inclusion criteria comprised single-level or two-level TLIF for degenerative spondylolisthesis with stenosis and at least one year of clinical and radiographic follow-up. Variables of interest included pertinent preoperative, perioperative, and postoperative data. Non-parametric evaluation was performed using the Wilcoxon test. Fisher's exact test was used to assess group differences for nominal data. RESULTS: Overall, 140 patients met the inclusion criteria; 69 patients had CBT instrumentation (mean follow-up 526 days) and 71 patients underwent instrumentation placement via TPS (mean follow-up 825 days). Examination of perioperative and postoperative outcomes demonstrate comparable results between the groups with perioperative complications, length of stay, discharge destination, surgical revision rate, and fusion rates all being similar between groups (p = 0.1; p = 0.53; p = 0.091; p = 0.61; p = 0.665, respectively). CONCLUSIONS: CBT in the setting of TLIF offer equivalent outcomes to TPS with TLIF at both short- and long-term intervals of care.

A component method to delineate surgical spine implants for proton Monte Carlo dose calculation.

PURPOSE: Metallic implants have been correlated to local control failure for spinal sarcoma and chordoma patients due to the uncertainty of implant delineation from computed tomography (CT). Such uncertainty can compromise the proton Monte Carlo dose calculation (MCDC) accuracy. A component method is proposed to determine the dimension and volume of the implants from CT images. METHODS: The proposed component method leverages the knowledge of surgical implants from medical supply vendors to predefine accurate contours for each implant component, including tulips, screw bodies, lockers, and rods. A retrospective patient study was conducted to demonstrate the feasibility of the method. The reference implant materials and samples were collected from patient medical records and vendors, Medtronic and NuVasive. Additional CT images with extensive features, such as extended Hounsfield units and various reconstruction diameters, were used to quantify the uncertainty of implant contours. RESULTS: For in vivo patient implant estimation, the reference and the component method differences were 0.35, 0.17, and 0.04 cm3 for tulips, screw bodies, and rods, respectively. The discrepancies by a conventional threshold method were 5.46, 0.76, and 0.05 cm3 , respectively. The mischaracterization of implant materials and dimensions can underdose the clinical target volume coverage by 20 cm3 for a patient with eight lumbar implants. The tulip dominates the dosimetry uncertainty as it can be made from titanium or cobalt-chromium alloys by different vendors. CONCLUSIONS: A component method was developed and demonstrated using phantom and patient studies with implants. The proposed method provides more accurate implant characterization for proton MCDC and can potentially enhance the treatment quality for proton therapy. The current proof-of-concept study is limited to the implant characterization for lumbar spine. Future investigations could be extended to cervical spine and dental implants for head-and-neck patients where tight margins are required to spare organs at risk.

Telemedicine in Spine Surgery: Outcomes for 138 Patients With Virtual Preoperative Assessment Compared to Historical Controls.

INTRODUCTION: COVID-19 has accelerated the use of telemedicine in all aspects of health care delivery, including initial surgical evaluation. No existing literature investigates the safety and efficacy of telemedicine to preoperatively evaluate spine surgery candidates. Our objectives were: (1) Compare the change in visual analogue scale (VAS) scores between the telemedicine preoperative visit and in-person preoperative visit groups. (2) Compare the average surgical time, estimated blood loss (EBL), length of hospital stay (LOS), rates of intraoperative complications, rates of readmission, and rates of reoperation between the telemedicine preoperative visit and in-person preoperative visit groups. METHODS: The previously stated metrics were collected for 276 patients, 138 who were exclusively evaluated preoperatively with telemedicine and 138 historical controls who were evaluated preoperatively in person. We used χ2 and independent samples t tests to determine significance. RESULTS: There were no significant differences in the mean change in VAS scores (-2.7 ± 3.1 telemedicine vs. -2.2 ± 3.7 in-person, P = 0.317), mean percentage change in VAS scores (-40.5% ± 54.3% vs. -39.5% ± 66.6%, P = 0.811), mean surgical time (2.4 ± 1.4 hours vs. 2.3 ± 1.3 ours, P = 0.527), mean EBL (150.4 ± 173.3 mL vs. 156.7 ± 255.0 mL, P = 0.811), mean LOS (3.3 ± 2.4 days vs. 3.3 ± 2.5 days, P = 0.954), intraoperative complication rates (0.7% vs. 1.4%, P = 0.558), reoperation rates (7.9% vs. 4.3%, P = 0.208), or readmission rates (10.1% vs. 5.1%, P = 0.091) between the telemedicine preoperative visit and in-person preoperative visit groups. CONCLUSIONS: Preoperative evaluation via telemedicine leads to the same short-term surgical outcomes as in-person evaluation with no increased risk of surgical complications.

Risk of intracranial haemorrhage and ischaemic stroke after convexity subarachnoid haemorrhage in cerebral amyloid angiopathy: international individual patient data pooled analysis.

OBJECTIVE: To investigate the frequency, time-course and predictors of intracerebral haemorrhage (ICH), recurrent convexity subarachnoid haemorrhage (cSAH), and ischemic stroke after cSAH associated with cerebral amyloid angiopathy (CAA). METHODS: We performed a systematic review and international individual patient-data pooled analysis in patients with cSAH associated with probable or possible CAA diagnosed on baseline MRI using the modified Boston criteria. We used Cox proportional hazards models with a frailty term to account for between-cohort differences. RESULTS: We included 190 patients (mean age 74.5 years; 45.3% female) from 13 centers with 385 patient-years of follow-up (median 1.4 years). The risks of each outcome (per patient-year) were: ICH 13.2% (95% CI 9.9-17.4); recurrent cSAH 11.1% (95% CI 7.9-15.2); combined ICH, cSAH, or both 21.4% (95% CI 16.7-26.9), ischemic stroke 5.1% (95% CI 3.1-8) and death 8.3% (95% CI 5.6-11.8). In multivariable models, there is evidence that patients with probable CAA (compared to possible CAA) had a higher risk of ICH (HR 8.45, 95% CI 1.13-75.5, p = 0.02) and cSAH (HR 3.66, 95% CI 0.84-15.9, p = 0.08) but not ischemic stroke (HR 0.56, 95% CI 0.17-1.82, p = 0.33) or mortality (HR 0.54, 95% CI 0.16-1.78, p = 0.31). CONCLUSIONS: Patients with cSAH associated with probable or possible CAA have high risk of future ICH and recurrent cSAH. Convexity SAH associated with probable (vs possible) CAA is associated with increased risk of ICH, and cSAH but not ischemic stroke. Our data provide precise risk estimates for key vascular events after cSAH associated with CAA which can inform management decisions.

Spinal Arachnoid Webs: Presentation, Natural History, and Outcomes in 38 Patients.

BACKGROUND: Spinal arachnoid webs are rarely described bands of thickened arachnoid tissue in the dorsal thoracic spine. Much is unknown regarding their origins, risk factors, natural history, and outcomes. OBJECTIVE: To present the single largest case series, detailing presenting symptoms and outcomes amongst operative and nonoperative patients, to better understand the role of intervention. METHODS: This retrospective chart review identified 38 patients with arachnoid webs. Patient demographics, radiologic signs, symptoms, and surgical history data were extracted from the electronic medical record. Symptoms were divided by location and character. 28 patients were successfully contacted for follow up outcome surveys. RESULTS: 26 patients (68%) underwent surgical intervention, 12 (32%) were managed non-operatively. 15 (39%) patients had undergone a previous unsuccessful surgery at a different site for their symptoms prior to arachnoid web diagnosis. Commonly presenting symptoms included myelopathy (68%), focal thoracic back pain (68%), lower extremity weakness (45%), numbness and sensory changes (58%), and lower extremity radicular pain (42%), upper extremity weakness (24%), and radicular pain (37%). Focal thoracic pain was associated with thoracic level (P < .02). Myelopathic symptoms were less common in postoperative patients. Postoperative patients described significantly more upper extremity (P < .01) and thoracic (P < .01) numbness and paresthesias. Surveyed nonoperative patients universally described their symptoms as either stable or worsening. CONCLUSION: Spinal arachnoid webs present with thoracic myelopathy and back pain but can also present with upper extremity symptoms. Surgical intervention stabilizes or improves symptoms and is well received. Nonoperative patients do not spontaneously improve.

Current Procedural Terminology-based Procedure Categorization Enhances Cost Prediction of Medicare Severity Diagnosis Related Group in Spine Surgery.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: The aim of this study was to analyze how a Current Procedural Terminology (CPT)-based categorization method can predict cost variation in surgical spine procedures. SUMMARY OF BACKGROUND DATA: Neck and back disorders affect a majority of the adult population and account for tens of billions of dollars in health care spending each year. In the era of bundled payments and value-based reimbursement, it is imperative for surgeons to identify sources of cost variability across surgical spine procedures. Historically, this has been accomplished using Medicare Severity Diagnosis Related Group (MS-DRG) codes, but they utilize an overly simplistic categorization of surgical procedures. The specificity and familiarity of the CPT coding structure makes it a better option for categorizing differences in surgical decision making and technique. METHODS: Hospital billing data for patients undergoing a surgical spine procedure requiring an overnight, in-patient stay was retrospectively collected over 4 fiscal years (2012-2016) from a single health care system. Linear regression analysis was performed to assess the correlation between cost variation and: spine-specific MS-DRG codes; a novel CPT-based categorization method; and the combination of MS-DRG codes and CPT-based categorization. RESULTS: There were 5020 surgical procedures were analyzed with respect to 16 different MS-DRG codes and 30 distinct CPT-based surgical categories (CSCs). Linear regression results were: MS-DRG R2 = 0.6545 (P < 0.001); CSC R2 = 0.5709 (P < 0.001); and R2 = 0.744 for the combined MS-DRG and CSC methods (P < 0.05). Median difference between the actual and predicted cost for the combined model was -$261.00, compared with -$727.50 for the CSC model and -$478.70 for the MS-DRG model. CONCLUSION: Addition of the CPT-based categorization method to MS-DRG coding provides an enhanced method to evaluate the association between predicted and actual cost when using linear regression analysis to assess cost variation in spine surgery.Level of Evidence: 3.

Telemedicine in the Evaluation and Management of Neurosurgical Spine Patients: Questionnaire Assessment of 346 Consecutive Patients.

STUDY DESIGN: Retrospective questionnaire study of all patients seen via telemedicine during the COVID-19 pandemic at a large academic institution. OBJECTIVE: This aim of this study was to compare patient satisfaction of telemedicine clinic to in-person visits; to evaluate the preference for telemedicine to in-person visits; to assess patients' willingness to proceed with major surgery and/or a minor procedure based on a telemedicine visit alone. SUMMARY OF BACKGROUND DATA: One study showed promising utility of mobile health applications for spine patients. No studies have investigated telemedicine in the evaluation and management of spine patients. METHODS: An 11-part questionnaire was developed to assess the attitudes toward telemedicine for all patients seen within a 7-week period during the COVID-19 crisis. Patients were called by phone to participate in the survey. χ2 and the Wilcoxon Rank-Sum Test were performed to determine significance. RESULTS: Ninety-five percent were "satisfied" or "very satisfied" with their telemedicine visit, with 62% stating it was "the same" or "better" than previous in-person appointments. Patients saved a median of 105 minutes by using telemedicine compared to in-person visits. Fifty-two percent of patients have to take off work for in-person visits, compared to 7% for telemedicine. Thirty-seven percent preferred telemedicine to in-person visits. Patients who preferred telemedicine had significantly longer patient-reported in-person visit times (score mean of 171) compared to patients who preferred in-person visits (score mean of 137, P = 0.0007). Thirty-seven percent of patients would proceed with surgery and 73% would proceed with a minor procedure based on a telemedicine visit alone. CONCLUSION: Telemedicine can increase access to specialty care for patients with prolonged travel time to in-person visits and decrease the socioeconomic burden for both patients and hospital systems. The high satisfaction with telemedicine and willingness to proceed with surgery suggest that remote visits may be useful for both routine management and initial surgical evaluation for spine surgery candidates.Level of Evidence: 3.

A Retrospective Chart Review on the Role of Suppressive Therapy in the Management of Spinal Infections Involving Hardware.

BACKGROUND: One percent to 8% of patients undergoing spinal instrumentation surgeries develop infections. There is no consensus on the medical and surgical management of these infections. METHODS: We conducted a retrospective chart review based on International Classification of Diseases, Ninth Revision, and Common Procedural Terminology codes relevant to spinal infections with hardware within Emory Healthcare over a 10-year period. Extracted data included patient demographics, clinical presentation, laboratory and microbiologic results, and surgical and medical management including choice and duration of suppressive therapy. Multivariable logistic regression was used to assess the association of length of use of suppressive antibiotics with treatment success and to identify predictors of use of suppressive antibiotics. RESULTS: Of 869 records, 124 met inclusion criteria. Fifty patients (40.3%) had an infection that occurred after hardware placement, mostly within 3 months postsurgery, while the remainder had vertebral osteomyelitis that required hardware placement. After initial intravenous antibiotic treatment for ≥4 weeks, 72 patients (64.5%) were given suppressive antibiotics. The overall treatment success rate was 78.2%. In spinal infections involving hardware with gram-negative rods, patients were less likely to receive suppressive antibiotics, less likely to have hardware removed, and less likely to have treatment success compared with patients with infections with Staphylococcus species. CONCLUSIONS: Management of spinal infections involving hardware should be tailored to the timing of onset of infection and causative organism. Further studies are needed to determine best management practices, particularly for gram-negative rod infections where the role of further suppressive antibiotics and hardware removal may be warranted.

Safety Profile and Radiographic and Clinical Outcomes of Stand-Alone 2-Level Anterior Lumbar Interbody Fusion: A Case Series of 41 Consecutive Patients.

OBJECTIVE: The use of stand-alone 2-level anterior lumbar interbody fusion (ALIF) for degenerative lumbar disease has been increasing as an alternative to routinely augmenting these constructs with posterior fixation or fusion. Despite the potential benefits of a stand-alone approach (decreased cost and operative time, decreased pain and early mobilization), there is a paucity of information regarding these operations in the literature. This investigation aimed to determine the safety profile, radiographic outcomes including fusion rates, improvement in preoperative pain, and spinopelvic parameter modification, for patients undergoing stand-alone 2-level ALIF. METHODS: This retrospective case series involved a chart review of all patients undergoing 2-level stand-alone ALIF at a single tertiary hospital from 2008 to 2018. Data included patient demographics, hospitalization, complications and radiological studies. Visual analog scale (VAS) back and leg scores were measured via patient-administered surveys preoperatively and up to 18 weeks postoperatively. RESULTS: Forty-one patients who underwent L4-S1 stand-alone ALIF were included. Sixteen (39%) of patients had undergone previous posterior lumbar surgery. Length of stay averaged 4.2 days. Complication rates were comparable to 1-level ALIF. Two patients required reoperation. Fusion rates were 100% for L4-5 and 94.4% for L5-S1. There was no significant change in lumbar lordosis (LL) or LL-pelvic incidence (PI), but there was improved segmental lordosis (SL) and disc height at L4-S1 on final follow-up imaging. There was also modest but statistically significant improvement in VAS back and leg scores. CONCLUSIONS: Stand-alone 2-level ALIF is an option for a surgeon to perform in the absence of significant instability, even in the setting of prior posterior surgery. These procedures increase SL and disc height, but do not have the same effect on LL or LL-PI.

The Use of Anterior Lumbosacral Interbody Fusion in Spinopelvic Stabilization After High Partial Sacrectomy.

BACKGROUND AND IMPORTANCE: Traditionally, when a patient presents with a midline chordoma with extension to the mid-S1 body where neither S1 nerve roots can be spared, the recommendation would be to perform a total sacrectomy for en bloc resection. This procedure, however, results in a large bony defect that makes it difficult to achieve fusion across the lumbosacral and sacroiliac junction (SIJ). To help prevent this challenge in the situation described above, we propose performing a high sacrectomy for en bloc resection with placement of an anterior L5-S1 graft instead in specific situations where the tumor extends to the mid-S1 body leaving the superior aspect of S1 unaffected. CLINICAL PRESENTATION: A 56-yr-old female presented to our clinic with back pain, leg pain, urinary incontinence, and perineal numbness. She was found to have a chordoma that extended to the mid-S1 body superiorly. Her S1 nerve roots were involved extraforaminally. We performed the operation described above with no signs of hardware malfunction or tumor recurrence at 5 mo. CONCLUSION: In patients where the sacral tumor that involves the S1 nerve roots but does not involve the superior portion of the S1 body, there continues to be unaffected SIJ to allow for arthrodesis, and an anterior approach is necessary for other indications, we recommend performing a high partial sacrectomy with placement of an anterior L5-S1 graft rather than a total sacrectomy as long as the bony resection offers ability to obtain tumor margins.

Comparing Cortical Trajectory Transforaminal Lumbar Interbody Fusions Against Pedicle Trajectory Transforaminal Lumbar Interbody Fusions and Posterolateral Fusions: A Retrospective Cohort Study of 90-day Outcomes.

BACKGROUND: The cortical screw (CS) trajectory for pedicle screw placement is believed to require a smaller incision and less tissue dissection resulting in lower blood loss and faster healing; however, this has not yet been confirmed in clinical studies. OBJECTIVE: To compare CS transforaminal lumbar interbody fusions (TLIF), traditional pedicle screw (TPS) trajectory TLIFs, and posterolateral fusion (PLF) without interbody for differences in operative characteristics and complications. METHODS: We performed a retrospective cohort study (CS, TPS, and PLF) looking at patients who underwent lumbar fusion with 1 or 2 levels. Extracted data included demographics, comorbidities, estimated blood loss, transfusions, operative time, length of stay, discharge disposition (home vs rehabilitation), and complications within the perioperative, 30- and 90-d periods. RESULTS: A total of 118 patients (45 CS, 35 TPS, and 38 PLF) were included with average age 62 and 90-d follow-up for 106 (90%) patients. CS had less average blood loss (231 ml) than either TPS (424, P = .0023) or PLF (400, P = .0070). CS had far fewer transfusions than either TPS or PLF (P < .0001). TPS had longer average operating room (OR) time (262 min) than either CS (214, P = .0075) or PLF (211, P = .0060). CS had the shortest length of postoperative stay (4.3 days) which was significantly shorter than PLF (6.2, P = .0138) but not different than TPS (4.8). There were no differences in discharge disposition, complications, perioperative, 30-d, 90-d, durotomy, or wound healing issues. CONCLUSION: The CS trajectory is associated with less blood loss, fewer transfusions, reduced OR time, and shorter length of stay, with no difference in complications.

Anterior Cervical Discectomy and Fusion: Comparison of Fusion, Dysphagia, and Complication Rates Between Recombinant Human Bone Morphogenetic Protein-2 and Beta-Tricalcium Phosphate.

INTRODUCTION: Anterior cervical discectomy and fusion (ACDF) is one of the most common spinal procedures performed. A direct comparison of the fusion and complication rates between recombinant human bone morphogenetic protein-2 (rhBMP2) and beta-tricalcium phosphate (bTCP) has not been reported. METHODS: A retrospective study of 191 consecutive patients who underwent ACDF with polyetheretherketone plastic fusion spacers during a 2-year period with either rhBMP2 (n = 84, 46%) or bTCP (n = 107, 56%) was performed. Patients underwent 1- (35%), 2- (41%), 3- (20%), and 4- (4%) level operations. The primary outcome measure was mature arthrodesis, with secondary measures including clinical outcomes and complication occurrence. Fusion was graded on plain lateral radiographs, with median length of follow-up of 12 months. RESULTS: Rates of cervical fusion were significantly greater for patients treated with rhBMP2 than bTCP at both 6 months (70% vs. 26%, P = 0.000) and 12 months (99% vs. 85%, P = 0.000). Postoperative dysphagia was reported in 35 patients (18%), with no difference in dysphagia incidence between rhBMP2 and bTCP (20% vs. 17%, P = 0.5); however, dysphagia was more severe in the rhBMP2 group, with greater rates of readmission and steroid use (both P < 0.05). A multivariable sensitivity analyses to control for patient characteristics and number of spinal fusion levels showed no differences in dysphagia rate between rhBMP2 and bTCP. CONCLUSIONS: In our cohort, the rate of mature arthrodesis after ACDF was greater with rhBMP2 compared with bTCP with no increased incidence of postoperative dysphagia; however, dysphagia severity was greater in the rhBMP2 cohort.

Efficacy of Transsacral Instrumentation for High-Grade Spondylolisthesis at L5-S1: A Systematic Review of the Literature.

BACKGROUND: High-grade L5-S1 spondylolisthesis is challenging to treat, and there is no standard recommended operative technique. The authors performed a systematic review of the literature evaluating the efficacy and safety of modern transsacral instrumentation techniques for high-grade L5-S1 spondylolisthesis. METHODS: A systematic PubMed search adherent to PRISMA guidelines included relevant clinical studies reporting transsacral instrumentation for high-grade L5-S1 spondylolisthesis in adult humans from 1980 onward. Available data regarding clinical and radiographic outcomes for individual patients were abstracted. RESULTS: Nine of 311 studies were eligible for detailed review. They reported on 38 patients (mean 33.1 years; range 18-66 years) treated with transsacral instrumentation. Transsacral cages (6 articles, n = 23), screws (2 articles, n = 12) and rods (1 article, n = 3) were used. Posterior (86.8%) and combined anteroposterior approaches were used, both with (55.2%) and without decompression, partial reduction (23.7%), posterior pedicle screw fixation (94.7%), and adjacent level inter-body fusion (42.1%). Four patients had 6 perioperative complications (15.8%). Mean follow-up time was 30.1 months (range 2-58 months; n = 37). All patients had adequate fusion on follow-up imaging (n = 34) and no progression of slip (n = 32). All patients had improvement in pain (n = 32) and at least average function postoperatively (94.7%; n = 33/35). CONCLUSION: Operative techniques for managing high-grade L5-S1 spondylolisthesis are evolving. In our systematic review, modern transsacral instrumentation resulted in good clinical outcome and fusion rates, and acceptable complication rates. Risks and benefits should be individualized for each patient. Transsacral instrumentation is a viable and effective treatment option for this pathology.

Esophageal perforation after anterior cervical spine surgery: a systematic review of the literature.

OBJECTIVE Esophageal perforation is a rare but well-known complication of anterior cervical spine surgery. The authors performed a systematic review of the literature to evaluate symptomatology, direct causes, repair methods, and associated complications of esophageal injury. METHODS A PubMed search that adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines included relevant clinical studies and case reports (articles written in the English language that included humans as subjects) that reported patients who underwent anterior spinal surgery and sustained some form of esophageal perforation. Available data on clinical presentation, the surgical procedure performed, outcome measures, and other individual variables were abstracted from 1980 through 2015. RESULTS The PubMed search yielded 65 articles with 153 patients (mean age 44.7 years; range 14-85 years) who underwent anterior spinal surgery and sustained esophageal perforation, either during surgery or in a delayed fashion. The most common indications for initial anterior cervical spine surgery in these cases were vertebral fracture/dislocation (n = 77), spondylotic myelopathy (n = 15), and nucleus pulposus herniation (n = 10). The most commonly involved spinal levels were C5-6 (n = 51) and C6-7 (n = 39). The most common presenting symptoms included dysphagia (n =63), fever (n = 24), neck swelling (n = 23), and wound leakage (n = 18). The etiology of esophageal perforation included hardware failure (n = 31), hardware erosion (n = 23), and intraoperative injury (n = 14). The imaging modalities used to identify the esophageal perforations included modified contrast dye swallow studies, CT, endoscopy, plain radiography, and MRI. Esophageal repair was most commonly achieved using a modified muscle flap, as well as with primary closure. Outcomes measured in the literature were often defined by the time to oral intake following esophageal repair. Complications included pneumonia (n = 6), mediastinitis (n = 4), osteomyelitis (n = 3), sepsis (n = 3), acute respiratory distress syndrome (n = 2), and recurrent laryngeal nerve damage (n = 1). The mortality rate of esophageal perforation in the analysis was 3.92% (6 of 153 reported patients). CONCLUSIONS Esophageal perforation after anterior cervical spine surgery is a rare complication. This systematic review demonstrates that these perforations can be stratified into 3 categories based on the timing of symptomatic onset: intraoperative, early postoperative (within 30 days of anterior spinal surgery), and delayed. The most common source of esophageal injury is hardware erosion or migration, each of which may vary in their time to symptomatic manifestation.