Prospective comparison of dysphagia following anterior cervical discectomy and fusion (ACDF) with and without rhBMP-2.

BACKGROUND CONTEXT: Previous studies have called into question the safety of using rhBMP-2 in anterior cervical fusion due to the possibility of airway compromise and dysphagia. A retrospective chart review identified a significant increase in the severity of dysphagia after II-level ACDF with rhBMP-2 compared to patients who did not receive rhBMP-2. To date, this topic has not been studied prospectively. PURPOSE: Compare the incidence of dysphagia following anterior cervical discectomy and fusion (ACDF) when recombinant human bone morphogenetic protein-2 (rhBMP-2) is used with allograft compared to allograft alone. STUDY DESIGN: Prospective cohort study. PATIENT SAMPLE: A total of 114 patients completed a baseline SWAL-QOL survey and met the inclusion criteria. Thirty-nine patients underwent I- or II-level ACDF with allograft plus 0.5mg rhBMP-2/level. 44 patients underwent ACDF with allograft alone. Thirty-one patients undergoing a lumbar decompression were enrolled in a third cohort to control for dysphagia secondary to intubation. OUTCOME MEASURES: The primary outcome measure was the 14-point SWAL-QOL dysphagia questionnaire. Other patient factors obtained from anesthesia and operative records were examined to evaluate their potential relationship to postoperative dysphagia. METHODS: The 14-point SWAL-QOL questionnaire was administered at multiple time points (pre-op, post-op 7 days, 6 weeks, 6 months, and at least 1 year). Multivariable repeated-measures analysis was applied to data. RESULTS: Baseline adjusted SWAL-QOL means 7 days after surgery were significantly different between the three study groups. These differences resolved by 6 weeks postoperative, beyond which point there were no differences. At final follow-up, baseline adjusted SWAL-QOL means at 1 year were similar for the three study groups. CONCLUSIONS: This single-center study of anterior cervical surgery demonstrated that the addition of rhBMP-2 to an ACDF increased postoperative dysphagia at 7 days after surgery, but these patients recover to levels comparable to those who underwent ACDF without rhBMP-2 or lumbar surgery within 6 weeks.

Improvement of coronal alignment in fractional low lumbar curves with the use of anterior interbody devices.

STUDY DESIGN: Retrospective chart review. OBJECTIVES: To determine if the addition of an anterior lumbar interbody fusion (ALIF) improves the fractional curve in adult spinal deformity correction when compared to posterior surgery alone. ALIF is commonly advocated to improve lordosis and fusion in adult deformity surgery. Improved fractional curve correction may help level the pelvis and minimize proximal malalignment. METHODS: Patients undergoing thoracolumbar fusion to the pelvis with S2AI screws for deformity were identified and stratified into patients who had an ALIF as part of their deformity correction procedure (ALIF + PSF), and those who had a posterior approach alone. The posterior approach (PSF) includes patients who had a posterolateral fusion with or without a transforaminal lumbar interbody fusion (TLIF). Radiographic parameters measured included pre-op and post-op fractional coronal curve Cobb angle, lumbar lordosis, pelvic tilt, pelvic incidence and sacral slope, major Cobb angle, coronal and sagittal SVA. RESULTS: There were 31 cases in the ALIF + PSF group and 28 in the PSF group. Baseline demographic characteristics of the two groups were similar. Mean pre-op fractional coronal Cobb (18.3° vs 13.4°, p = 0.027) was larger in the ALIF + PSF group, whereas lumbar lordosis (31.0° vs 33.6°, p = 0.487) and pelvic parameters were similar between the two groups. Post-op lumbar lordosis was similar (48.2° vs 43.0°, p = 0.092). Greater fractional coronal curve correction was achieved in the ALIF + PSF group (67%) compared to the PSF group (36%) with a smaller post-op fractional coronal curve in the ALIF + PSF group (6.1°) compared to the PSF group (8.6°, p = 0.053). CONCLUSION: There is a greater correction of the fractional curve in the ALIF + PSF group compared with the PSF group. While this may not be the primary indication for ALIF, it is a benefit which may facilitate overall deformity correction and leveling of the pelvis.

General Health Adverse Events Within 30 Days Following Anterior Cervical Discectomy and Fusion in US Patients: A Comparison of Spine Surgeons' Perceptions and Reported Data for Rates and Risk Factors.

STUDY DESIGN: Survey study and retrospective review of prospective data. OBJECTIVES: To contrast surgeons' perceptions and reported national data regarding the rates of postoperative adverse events following anterior cervical discectomy and fusion (ACDF) and to assess the accuracy of surgeons in predicting the impact of patient factors on such outcomes. METHODS: A survey investigating perceived rates of perioperative complications and the perceived effect of patient risk factors on the occurrence of complications following ACDF was distributed to spine surgeons at the Cervical Spine Research Society (CSRS) 2015 Annual Meeting. The equivalent reported rates of adverse events and impacts of patient risk factors on such complications were assessed in patients undergoing elective ACDF from the National Surgical Quality Improvement Program (NSQIP). RESULTS: There were 110 completed surveys from attending physicians at CSRS (response rate = 44%). There were 18 019 patients who met inclusion criteria in NSQIP years 2011 to 2014. The rates of 11 out of 17 (65%) postoperative adverse events were mildly overestimated by surgeons responding to the CSRS questionnaire in comparison to reported NSQIP data (overestimates ranged from 0.24% to 1.50%). The rates of 2 out of 17 (12%) postoperative adverse events were mildly underestimated by surgeons (range = 0.08% to 1.2%). The impacts of 5 out of 10 (50%) patient factors were overestimated by surgeons (range relative risk = 0.56 to 1.48). CONCLUSIONS: Surgeon estimates of risk factors for and rates of adverse events following ACDF procedures were reasonably nearer to national data. Despite an overall tendency toward overestimation, surgeons' assessments are roughly appropriate for surgical planning, expectation setting, and quality improvement initiatives.

Inaccuracies in ICD Coding for Obesity Would Be Expected to Bias Administrative Database Spine Studies Toward Overestimating the Impact of Obesity on Perioperative Adverse Outcomes.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To determine if International Classification of Diseases (ICD) coding for obesity is biased toward certain subgroups and how potential bias may influence the outcomes of database research in spine. SUMMARY OF BACKGROUND DATA: There has been increased use of national databases using administrative data in the spine surgery literature. Past research demonstrates that sensitivity of ICD codes for obesity is poor, but it is unknown if such inaccuracies are systematically biased and if they may bias studies utilizing such data. METHODS: Patients who underwent elective posterior lumbar fusion, 2013 to 2016, at a large academic hospital were identified. All ICD codes assigned to the encounter were obtained. Body mass index (BMI) was calculated based on height and weight. The sensitivity of ICD coding for obesity was calculated. Sensitivity was compared for subgroups defined by demographic, comorbidity, intraoperative, and postoperative factors. The association of obesity (as defined by BMI≥30 and ICD coding) with 30-day postoperative adverse events was tested with multivariate regression. RESULTS: The study included 796 patients. The overall sensitivity of ICD coding for obesity was 42.5%. The sensitivity of ICD coding for obesity was significantly higher in patients with greater BMI, diabetes, American Society of Anesthesiologists class≥III, increased length of stay, venous thromboembolism, any adverse event, and major adverse event. Multivariate analysis for determining outcomes of increased risk with obesity as defined by ICD coding included venous thromboembolism, major adverse events, and any adverse events. However, multivariate analysis for determining outcomes of increased risk with obesity defined by BMI did not yield any positive associations. CONCLUSION: ICD codes for obesity are more commonly assigned to patients with other comorbidities or postoperative complications. Further, use of such nonrandomly assigned ICD codes for obesity has the potential to skew studies to suggest greater associated adverse events than calculated BMI would demonstrate. LEVEL OF EVIDENCE: 3.

Comparison of 30-Day Complications Between Navigated and Conventional Single-level Instrumented Posterior Lumbar Fusion: A Propensity Score Matched Analysis.

STUDY DESIGN: Retrospective cohort comparison study. OBJECTIVE: To compare perioperative outcomes between navigated and conventional single-level instrumented posterior lumbar fusions in the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database. SUMMARY OF BACKGROUND DATA: Although multiple studies have investigated the accuracy of pedicle screw placement and radiation exposure with navigation, no study has compared perioperative complications between navigated and conventional posterior lumbar fusion. The potential benefits of navigation include improved accuracy of screw placement and reduced surgeon radiation exposure, but this is balanced by potential operative time and surgical site contamination/infection related to this bulky technology. METHODS: Patients who underwent navigated or conventional single-level posterior instrumented lumbar fusions were identified in the 2010-2015 NSQIP database. The usage of navigation was characterized. Patient characteristics and comorbidities were compared between the two treatment groups. Propensity score matching was done and comparisons were made for operative time, hospital length of stay, postoperative complications, and 30-day readmissions between the two cohorts. RESULTS: The percentage of navigated cases tended to increase over years studied to approximately 10%. After propensity matching to control potential confounding factors, statistical analysis revealed no significant difference in operative time and for most adverse events including wound infection, return to the operating room, and readmission. There were significantly lower blood transfusions in the navigated cohort (2.84% vs. 7.15%, P < 0.001). Patients who underwent navigated surgery also had a shorter mean hospital length of stay (0.2 day difference, P = 0.016). CONCLUSION: The reduced blood loss and mildly reduced hospital length of stay identified for the navigated cases are probably markers of more minimally invasive surgery in the navigated cohort. The current study could not identify other differences in operative time, wound infection, or return to the operating room/readmission between navigated and conventional single level posterior instrumented lumbar cases. LEVEL OF EVIDENCE: 3.

Use of a Novel Pathway for Early Discharge Was Associated With a 48% Shorter Length of Stay After Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis.

INTRODUCTION: Hospital stay after posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS) has decreased only modestly over time despite a healthy patient population. The purpose of this study was to evaluate the impact of a novel postoperative pathway on length of stay (LOS) and complications. METHODS: A retrospective review of patients undergoing PSF for AIS in 2011 to 2012 was performed at 2 institutions evaluating demographics, preoperative Cobb angles, surgical duration, blood loss, LOS, and postoperative complications. Patients at one center were managed using an accelerated discharge (AD) pathway emphasizing early transition to oral pain medications mobilization with physical therapy 2 to 3 times/d, and discharge regardless of return of bowel function. Expectations were set with the family before surgery for early discharge. Patients at the other center were managed without a standardized pathway. RESULTS: One hundred five patients underwent PSF and were treated by an AD pathway, whereas 45 patients were managed using a traditional discharge (TD) pathway. There was no difference in proximal thoracic and main thoracic Cobb magnitudes and a small difference in thoracolumbar curve magnitudes (35.2±13.0 degrees AD vs. 40.6±11.4 degrees TD, P=0.004) between groups. Surgical time was slightly shorter in AD patients (median 3.1 vs. 3.9 h, P=0.0003) with no difference in estimated blood loss. LOS was 48% shorter in the AD group (2.2 vs. 4.2 d, P<0.0001). There was no difference in readmissions or wound complications between groups. CONCLUSIONS: Hospital stay was nearly 50% shorter in patients managed by the AD pathway without any increase in readmissions or early complications. SIGNIFICANCE: Discharge after PSF for AIS may be expedited using a coordinated postoperative pathway. No increase in complications was seen using the AD pathway. Earlier discharge may reduce health care costs and allow an earlier return to normalcy for families. LEVEL OF EVIDENCE: Level III-case control study.

Primary and Revision Posterior Lumbar Fusion Have Similar Short-Term Complication Rates.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To compare short-term morbidity for primary and revision posterior lumbar fusions. SUMMARY OF BACKGROUND DATA: Revision lumbar fusions are unfortunately relatively common. Previous studies have described an increased risk of postoperative complications after revision lumbar fusion; however, these studies have been limited by small sample sizes, poor data quality, and/or narrow outcome measures. There is a need to validate these findings using a high-quality, national cohort of patients to have an accurate assessment of the relative risk of revision posterior lumbar fusions compared with primary lumbar fusion. METHODS: The prospectively-collected American College of Surgeons National Surgical Quality Improvement Program database was used to identify patients that underwent undergoing primary and revision posterior lumbar fusion from 2005 to 2013. The occurrence of individual and aggregated postoperative complications within 30 days, along with rates of blood transfusion and readmission, were compared between primary and revision procedures using bivariate and multivariate Poisson regression with robust error variance to control for patient and operative characteristics. Operative time and postoperative length of stay were compared between groups using bivariate and multivariate linear regression. RESULTS: Of the 14,873 posterior lumbar fusion procedures that met inclusion criteria, 1287 (8.7%) were revision cases. There were no differences in the rates of 30-day postoperative complications or readmission between primary and revision posterior lumbar fusion using multivariate analysis to control for patient and operative characteristics. Similarly, no significant differences were found for operative time or postoperative length of stay. There was an increased rate of blood transfusion for revision surgery compared with primary surgery (relative risk 1.4, P < 0.001). CONCLUSION: This study suggests that revision posterior lumbar fusion does not carry significantly increased risk of complications or readmission compared with a primary posterior lumbar fusion. Patients undergoing revision surgery were more likely to receive a blood transfusion. This information suggests that general health risk stratification for revision procedures can be similar to that considered for primary cases. LEVEL OF EVIDENCE: 3.