Faculty Bibliography

STUDY DESIGN/METHODS:A retrospective multicenter study. OBJECTIVE:Routine cervical spine surgeries are typically associated with low complication rates, but serious complications can occur. Intraoperative death is a very rare complication and there is no literature on its incidence. The purpose of this study was to determine the intraoperative mortality rates and associated risk factors in patients undergoing cervical spine surgery. METHODS:Twenty-one surgical centers from the AOSpine North America Clinical Research Network participated in the study. Medical records of patients who received cervical spine surgery from January 1, 2005, to December 31, 2011, were reviewed to identify occurrence of intraoperative death. RESULTS:A total of 258 patients across 21 centers met the inclusion criteria. Most of the surgeries were done using the anterior approach (53.9%), followed by posterior (39.1%) and circumferential (7%). Average patient age was 57.1 ± 13.2 years, and there were more male patients (54.7% male and 45.3% female). There was no case of intraoperative death. CONCLUSIONS:Death during cervical spine surgery is a very rare complication. In our multicenter study, there was a 0% mortality rate. Using an adequate surgical approach for patient diagnosis and comorbidities may be the reason how the occurrence of this catastrophic adverse event was prevented in our patient population.

STUDY DESIGN/METHODS:A multicentered retrospective case series. OBJECTIVE:To determine the incidence and circumstances surrounding the development of a symptomatic postoperative epidural hematoma in the cervical spine. METHODS:Patients who underwent cervical spine surgery between January 1, 2005, and December 31, 2011, at 23 institutions were reviewed, and all patients who developed an epidural hematoma were identified. RESULTS:= .53). Additionally, the patients who experienced a postoperative epidural hematoma did not experience any significant improvement in health-related quality-of-life metrics as a result of the index procedure at final follow-up evaluation. CONCLUSION/CONCLUSIONS:This is the largest series to date to analyze the incidence of an epidural hematoma following cervical spine surgery, and this study suggest that an epidural hematoma occurs in approximately 1 out of 1000 cervical spine surgeries. Prompt diagnosis and treatment may improve the chance of making a complete neurologic recovery, but patients who develop this complication do not show improvements in the health-related quality-of-life measurements.

STUDY DESIGN/METHODS:Multicenter retrospective case series and review of the literature. OBJECTIVE:To determine the rate of esophageal perforations following anterior cervical spine surgery. METHODS:As part of an AOSpine series on rare complications, a retrospective cohort study was conducted among 21 high-volume surgical centers to identify esophageal perforations following anterior cervical spine surgery. Staff at each center abstracted data from patients' charts and created case report forms for each event identified. Case report forms were then sent to the AOSpine North America Clinical Research Network Methodological Core for data processing and analysis. RESULTS:The records of 9591 patients who underwent anterior cervical spine surgery were reviewed. Two (0.02%) were found to have esophageal perforations following anterior cervical spine surgery. Both cases were detected and treated in the acute postoperative period. One patient was successfully treated with primary repair and debridement. One patient underwent multiple debridement attempts and expired. CONCLUSIONS:Esophageal perforation following anterior cervical spine surgery is a relatively rare occurrence. Prompt recognition and treatment of these injuries is critical to minimizing morbidity and mortality.

STUDY DESIGN/METHODS:This study was a retrospective, multicenter cohort study. OBJECTIVES/OBJECTIVE:Rare complications of cervical spine surgery are inherently difficult to investigate. Pseudomeningocoele (PMC), an abnormal collection of cerebrospinal fluid that communicates with the subarachnoid space, is one such complication. In order to evaluate and better understand the incidence, presentation, treatment, and outcome of PMC following cervical spine surgery, we conducted a multicenter study to pool our collective experience. METHODS:This study was a retrospective, multicenter cohort study of patients who underwent cervical spine surgery at any level(s) from C2 to C7, inclusive; were over 18 years of age; and experienced a postoperative PMC. RESULTS:Thirteen patients (0.08%) developed a postoperative PMC, 6 (46.2%) of whom were female. They had an average age of 48.2 years and stayed in hospital a mean of 11.2 days. Three patients were current smokers, 3 previous smokers, 5 had never smoked, and 2 had unknown smoking status. The majority, 10 (76.9%), were associated with posterior surgery, whereas 3 (23.1%) occurred after an anterior procedure. Myelopathy was the most common indication for operations that were complicated by PMC (46%). Seven patients (53%) required a surgical procedure to address the PMC, whereas the remaining 6 were treated conservatively. All PMCs ultimately resolved or were successfully treated with no residual effects. CONCLUSIONS:PMC is a rare complication of cervical surgery with an incidence of less than 0.1%. They prolong hospital stay. PMCs occurred more frequently in association with posterior approaches. Approximately half of PMCs required surgery and all ultimately resolved without residual neurologic or other long-term effects.

STUDY DESIGN/METHODS:A multicenter retrospective case series was compiled involving 21 medical institutions. Inclusion criteria included patients who underwent cervical spine surgery between 2005 and 2011 and who sustained a vertebral artery injury (VAI). OBJECTIVE:To report the frequency, risk factors, outcomes, and management goals of VAI in patients who have undergone cervical spine surgery. METHODS:Patients were evaluated on the basis of condition-specific functional status using the Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) score, the Nurick scale, and the 36-Item Short-Form Health Survey (SF-36). RESULTS:= .20-.94). CONCLUSIONS:Vertebral artery injuries are potentially catastrophic complications that can be sustained from anterior or posterior cervical spine approaches. The data from this study suggest that with proper steps to ensure hemostasis, patients recover function at a high rate and do not exhibit residual deficits.

STUDY DESIGN/METHODS:Retrospective review. OBJECTIVE:The aim of our study was to quantify the frequency of complications associated with recombinant human bone morphogenetic protein 2 (rhBMP-2) use in anterior lumbar interbody fusion (ALIF). METHODS:The orthopedic subset of the Medicare database (PearlDiver) was queried for this retrospective cohort study using International Statistical Classification of Diseases 9 (ICD-9) and Current Procedure Terminology (CPT) codes for ALIF procedures with and without rhBMP-2 between 2005 and 2010. Frequencies of complications and reoperations were then identified within 1 year from the index procedure. Complications included reoperations, pulmonary embolus, deep vein thrombosis, myocardial infarction, nerve-related complications, incision and drainage procedures, wound, sepsis, pneumonia, urinary tract infections, respiratory, heterotopic ossification, retrograde ejaculation, radiculopathy, and other medical complications. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the statistical significance. RESULTS:We identified a total of 41 865 patients who had an ALIF procedure. A total of 14 384 patients received rhBMP-2 while 27 481 did not. Overall, 6016 (41.8%) complications within 1 year from surgery were noted within the group who received rhBMP-2 and 12 950 (47.1%) complications within 1 year from surgery were recorded in those who did not receive rhBMP-2 (OR = 0.81, CI = 0.77-0.84). Overall, exposure to rhBMP-2 was associated with significantly decreased odds of complications with exception to reoperation rates (0.9% rhBMP-2 vs 1.0% no rhBMP-2; OR = 0.88, CI = 0.71-1.09) and radiculopathy (4.4% rhBMP-2 vs 4.3% no rhBMP-2; OR = 1.02, CI = 0.93-1.13). CONCLUSIONS:The use of rhBMP-2 in patients undergoing ALIF procedure was associated with a significantly decreased rate of complications. Further studies are needed to elucidate a true incidence of complication.

STUDY DESIGN/METHODS:Retrospective cohort study of prospectively collected data. OBJECTIVE:To examine the incidence of iatrogenic spinal cord injury following elective cervical spine surgery. METHODS:A retrospective multicenter case series study involving 21 high-volume surgical centers from the AOSpine North America Clinical Research Network was conducted. Medical records for 17 625 patients who received cervical spine surgery (levels from C2 to C7) between January 1, 2005, and December 31, 2011, were reviewed to identify occurrence of iatrogenic spinal cord injury. RESULTS:In total, 3 cases of iatrogenic spinal cord injury following cervical spine surgery were identified. Institutional incidence rates ranged from 0.0% to 0.24%. Of the 3 patients with quadriplegia, one underwent anterior-only surgery with 2-level cervical corpectomy, one underwent anterior surgery with corpectomy in addition to posterior surgery, and one underwent posterior decompression and fusion surgery alone. One patient had complete neurologic recovery, one partially recovered, and one did not recover motor function. CONCLUSION/CONCLUSIONS:Iatrogenic spinal cord injury following cervical spine surgery is a rare and devastating adverse event. No standard protocol exists that can guarantee prevention of this complication, and there is a lack of consensus regarding evaluation and treatment when it does occur. Emergent imaging with magnetic resonance imaging or computed tomography myelography to evaluate for compressive etiology or malpositioned instrumentation and avoidance of hypotension should be performed in cases of intraoperative and postoperative spinal cord injury.

STUDY DESIGN/METHODS:Retrospective cohort study. OBJECTIVE:To examine the risk of undergoing another cervical spine surgery after single-level posterior cervical foraminotomy (PCF) and analyze the costs of such reoperations. METHODS:Using the PearlDiver database, we created database algorithms to identify cohorts of patients who underwent single-level PCF and also had various reoperations of interest, within 1, 2, and 4 years of follow-up. We also identified the per-patient average charge (PPAC) for each reoperation cohort. RESULTS:In the Medicare cohort, the incidence of any reoperation was 8.3%, 9.8%, and 10.5% within 1, 2, and 4 years of follow-up, respectively. The PPAC was $8520 for the initial PCF procedure. When a second cervical surgery was performed, the PPAC was $70 349 for anterior fusion, $15 760 for posterior decompression alone, and $77 976 for posterior decompression and fusion. In the UnitedHealth cohort, the incidence of any reoperation was 13.6%, 16.7%, and 17.0% within 1, 2, and 4 years of follow-up, respectively. CONCLUSIONS:The overall incidence of another cervical spine operation was slightly higher in the Medicare population to that in previous literature, but much higher in the UnitedHealth population. The most common reoperation after PCF varied between the Medicare and UnitedHealth datasets, and costs varied widely based on the procedure performed. This study provides pertinent information that surgeons can use to discuss the risk of reoperation with their patients.

STUDY DESIGN/METHODS:A retrospective database study. OBJECTIVE:The goal of this study was to (1) evaluate the trends in the use of intraoperative neuromonitoring (ION) for anterior cervical discectomy and fusion (ACDF) surgery in the United States and (2) assess the incidence of neurological injuries after ACDFs with and without ION. SUMMARY OF BACKGROUND DATA/BACKGROUND:Somatosensory-evoked potentials (SSEPs) and motor-evoked potentials (MEPs) are the commonly used ION modalities for ACDFs. Controversy exists on the routine use of ION for ACDFs and there is limited literature on national practice patterns of its use. METHODS:A retrospective review was performed using the PearlDiver Patient Record Database to identify cases of spondylotic myelopathy and radiculopathy that underwent ACDF from 2007 to 2014. The type of ION modality used and the rates of neurological injury after surgery were assessed. RESULTS:During the study period, 15,395 patients underwent an ACDF. Overall, ION was used in 2627 (17.1%) of these cases. There was a decrease in the use of ION for ACDFs from 22.8% in 2007 to 4.3% use in 2014 (P < 0.0001). The ION modalities used for these ACDFs were quite variable: SSEPs only (48.7%), MMEPs only (5.3%), and combined SSEPs and MMEPs (46.1%). Neurological injuries occurred in 0.23% and 0.27% of patients with and without ION, respectively (P = 0.84). Younger age was associated with a higher utility of ION (<45: 20.3%, 45-54: 19.3%, 55-64: 16.6%, 65-74: 14.3%, and >75: 13.6%, P < 0.0001). Significant regional variability was observed in the utility of ION for ACDFs across the country (West; 21.9%, Midwest; 12.9% (P < 0.0001). CONCLUSION/CONCLUSIONS:There has been a significant decrease in the use of ION for ACDFs. Furthermore, there was significant age and regional variability in the use of ION for ACDFs. Use of ION does not further prevent the rate of postoperative neurological complications for ACDFs as compared with the cases without ION. The utility of routine ION for ACDFs is questionable. LEVEL OF EVIDENCE/METHODS:3.

OBJECT:To investigate the efficacy of debridement, open drainage, and early feeding to treat early esophageal fistula complicated with anterior cervical surgery. METHODS:Retrospective analysis was conducted on data from 3154 patients who had undergone anterior cervical surgeries for cervical vertebra diseases between January 2006 and January 2013, in which eight patients had esophageal fistula with five males and three females. Four patients had cervical spinal injuries and four patients had cervical spondylosis. All of whom had postoperative esophageal fistulas and underwent debridement and drainage. The wounds were left open for natural drainage. No drainage devices were placed in surgical sites, and no gastric tubes were placed after surgeries. Such normal food as rice balls but not liquid or semiliquid diet was recommended. Local pressurization was conducted with fists during feeding to prevent food overflowing from orificium fistulae. RESULTS:Healed esophageal fistulas were achieved in all of the patients after 1-2 weeks treatment. There weren't recurrent esophageal fistulas and delayed infection found during 2-5 years follow-up. Good swallowing functions and stable cervical vertebrae were achieved in all of the patients. The satisfactory therapeutic effects were achieved in patients with previous neck diseases. Frankel classifications were increased by 1-2 grades in patients with cervical spinal injuries. JOA scores were increased from 9.5 before surgery to 15.5 after surgery in patients with cervical vertebra diseases. CONCLUSIONS:Early postoperative esophageal fistula complication after anterior cervical surgery can successfully be treated by debridement, drainage without gastric tube, and with early oral postoperative feeding but without fluids.