Faculty Bibliography

STUDY DESIGN/METHODS:Retrospective analysis of a nationwide private insurance database. Chi-square analysis and linear regression models were utilized for outcome measures. PURPOSE/OBJECTIVE:The purpose of this study was to investigate any relationship between lumbar degenerative disc disease, diabetes, obesity and smoking tobacco. OVERVIEW OF LITERATURE/BACKGROUND:Diabetes, obesity, and smoking tobacco are comorbid conditions known to individually have effect on degenerative disc disease. Most studies have only been on a small populous scale. No study has yet to investigate the combination of these conditions within a large patient cohort nor have they reviewed the combination of these conditions on degenerative disc disease. METHODS:A retrospective analysis of insurance billing codes within the nationwide Humana insurance database was performed, using PearlDiver software (PearlDiver, Inc., Fort Wayne, IN, USA), to identify trends among patients diagnosed with lumbar disc degenerative disease with and without the associated comorbidities of obesity, diabetes, and/or smoking tobacco. Patients billed for a comorbidity diagnosis on the same patient record as the lumbar disc degenerative disease diagnosis were compared over time to patients billed for lumbar disc degenerative disease without a comorbidity. There were no sources of funding for this manuscript and no conflicts of interest. RESULTS:<0.05). CONCLUSIONS:Diabetes, obesity and cigarette smoking each are significantly associated with an increased diagnosis of lumbar degenerative disc disease. The combination of smoking and obesity had a synergistic effect on increased rates of lumbar degenerative disc disease. Patient education and preventative care is a vital goal in prevention of degenerative disc disease within the general population.

STUDY DESIGN/METHODS:Retrospective database review. OBJECTIVE:To analyze and report the trends and cost of posterior cervical fusions (PCFs) with and without off-label recombinant human bone morphogenetic protein-2 (rhBMP-2) in the Medicare population. METHODS:Patient records from the PearlDiver database were retrospectively reviewed from January 1, 2005, to December 31, 2012, to distinguish individuals who underwent a PCF with or without rhBMP-2. Total numbers, incidence, age, gender, geographic region, reimbursement, and length of stay were analyzed and summarized. RESULTS:The combined total of non-rhBMP-2 (n = 39 479; 85.51%) and rhBMP-2 PCF (n = 6692; 14.49%) procedures performed between 2005 and 2012 was 46 171. In general, the number of PCFs without rhBMP-2 consistently increased over time, while the number of PCFs with rhBMP-2 had only a slight increase from 2005 to 2012. On average, PCFs without rhBMP-2 were associated with $1197 higher cost than those with rhBMP-2, but the average length of stay was similar (6 days). From 2005 to 2012, the average cost for procedures with and without rhBMP-2 increased by $12 605 and $7291, respectively. The percentage of rhBMP-2 use peaked in 2007 and dwindled until 2010, and declined an additional 2.84% from 2011 to 2012. Multiple age, region, and gender tendencies were observed. CONCLUSIONS:To our knowledge, this was the first study to use the PearlDiver database to report incidence and cost trends of PCF procedures. This article provides meaningful trend data on PCFs to surgeons and clinicians, researchers, and patients, as well as functions as a beacon for future research questions.

STUDY DESIGN/METHODS:Retrospective analysis of national insurance billing database. OBJECTIVE:To examine trends in reoperation after single-level lumbar discectomy. SUMMARY OF BACKGROUND DATA/BACKGROUND:Lumbar discectomy is the most commonly performed procedure for treatment of radiculopathy caused by disc herniation. Randomized clinical trials have demonstrated the advantage of discectomy over nonsurgical treatment options, allowing for a more rapid reduction in symptoms. However, population-level data regarding reoperation after single level discectomy is limited. METHODS:Data were collected using the commercially available PearlDiver software for patients billed with the Current Procedural Terminology code for our index procedure, hemilaminotomy and removal of disc material, between January 2007 and September 2014. The index group was then followed for up to 4 years for recurrent lumbar surgery, including spinal fusion, laminectomy, and additional discectomy. RESULTS:Analysis of data obtained from 13,654 patient records revealed a rate of additional lumbar surgeries after single-level discectomy of 3.95% (539/13654) within 3 months and 12.2% (766/6274) within 4 years of the index procedure. Lumbar spinal fusion was performed on 5.9% (370/6274) of patients within 4 years. Patients who received a re-exploration discectomy within 2 years of the index procedure went on to receive lumbar fusion at a rate of 38.4% (48/125) within the 4 years after the re-exploration discectomy. The average additional cost of lumbar reoperation, as measured by insurance reimbursement, was approximately $11,161 per-patient per year. CONCLUSION/CONCLUSIONS:We report an overall 4-year reoperation rate of 12.2% after single-level discectomy. In addition, we report a rate of progression to lumbar fusion following re-exploration discectomy of 38.4% within 4 years of reoperation. Further studies are needed regarding the best treatment algorithm in patients with reherniation or iatrogenic instability after lumbar discectomy. This study should enhance the shared decision making process by providing surgeons and patients with valuable data regarding the frequency and nature of reoperations after discectomy. LEVEL OF EVIDENCE/METHODS:3.

STUDY DESIGN/METHODS:A multicenter, retrospective review of C5 palsy after cervical spine surgery. OBJECTIVE:Postoperative C5 palsy is a known complication of cervical decompressive spinal surgery. The goal of this study was to review the incidence, patient characteristics, and outcome of C5 palsy in patients undergoing cervical spine surgery. METHODS:tests or Fisher exact tests for categorical variables. RESULTS:Of the 13 946 cases reviewed, 59 patients experienced a postoperative C5 palsy. The incidence rate across the 21 sites ranged from 0% to 2.5%. At most recent follow-up, 32 patients reported complete resolution of symptoms (54.2%), 15 had symptoms resolve with residual effects (25.4%), 10 patients did not recover (17.0%), and 2 were lost to follow-up (3.4%). CONCLUSION/CONCLUSIONS:C5 palsy occurred in all surgical approaches and across a variety of diagnoses. The majority of patients had full recovery or recovery with residual effects. This study represents the largest series of North American patients reviewed to date.

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.