Jeremy Steinberger

Frailty Index Is a Significant Predictor of Complications and Mortality After Surgery for Adult Spinal Deformity

Study Design. Retrospective study of prospectively collected data. Objective. To determine if the modified Frailty Index (mFI) could be used to predict postoperative complications in patients undergoing surgery for adult spinal deformity (ASD). Summary of Background Data. Surgery for patients with ASD is associated with high complication rates and significant concerns present during risk stratification with older patients. The mFI is an evaluation tool to describe the frailness of an individual and how their preoperative status may impact postoperative survival and outcomes. Using a large nationwide database, we assessed the utility of this instrument in patients undergoing surgery for ASD. Methods. The American College of Surgeons National Surgical Quality Improvement Program is a large multicenter clinical registry that prospectively collects preoperative variables, patient demographics, operative factors, and 30-day postoperative morbidity and mortality outcomes from about 400 hospitals nationwide. Current Procedural Terminology codes were used to query the database for adults who underwent fusion for spinal deformity. The previously described mFI was calculated based on the number of positive factors and univariate and multivariate logistic regression analysis were used to analyze the risk factors associated with mortality. Results. Overall, 1001 patients were identified and the mean mFI score was 0.09 (range: 0–0.545). Increasing mFI score was associated with higher complication, reoperation, and mortality rates (P < 0.05). mFI of 0.09 and 0.18 was an independent predictor of any complication, mortality, requiring a blood transfusion, pulmonary embolism/deep vein thrombosis, and reoperation (all P < 0.05). In comparison with age >60 years obesity class III, mFI was a superior predictor of several postoperative complications and reoperation. Conclusion. Frailty was an independent predictor of postoperative complications, mortality, and reoperation in patients undergoing surgery for ASD. Preoperative assessment of the mFI in this patient population can be utilized to improve current risk models. Level of Evidence: 3

The Top 100 Classic Papers in Lumbar Spine Surgery

Study Design. Bibliometric review of the literature. Objective. To analyze and quantify the most frequently cited papers in lumbar spine surgery and to measure their impact on the entire lumbar spine literature. Summary of Background Data. Lumbar spine surgery is a dynamic and complex field. Basic science and clinical research remain paramount in understanding and advancing the field. While new literature is published at increasing rates, few studies make long-lasting impacts. Methods. The Thomson Reuters Web of Knowledge was searched for citations of all papers relevant to lumbar spine surgery. The number of citations, authorship, year of publication, journal of publication, country of publication, and institution were recorded for each paper. Results. The most cited paper was found to be the classic paper from 1990 by Boden et al that described magnetic resonance imaging findings in individuals without back pain, sciatica, and neurogenic claudication showing that spinal stenosis and herniated discs can be incidentally found when scanning patients. The second most cited study similarly showed that asymptomatic patients who underwent lumbar spine magnetic resonance imaging frequently had lumbar pathology. The third most cited paper was the 2000 publication of Fairbank and Pynsent reviewing the Oswestry Disability Index, the outcome-measure questionnaire most commonly used to evaluate low back pain. The majority of the papers originate in the United States (n = 58), and most were published in Spine (n = 63). Most papers were published in the 1990s (n = 49), and the 3 most common topics were low back pain, biomechanics, and disc degeneration. Conclusion. This report identifies the top 100 papers in lumbar spine surgery and acknowledges those individuals who have contributed the most to the advancement of the study of the lumbar spine and the body of knowledge used to guide evidence-based clinical decision making in lumbar spine surgery today. Level of Evidence: 3

Impact of Gender on 30-Day Complications After Adult Spinal Deformity Surgery.

Study Design. Retrospective study of prospectively collected data. Objective. To determine if postoperative morbidity for patients undergoing spinal deformity surgery varies by sex. Summary of Background Data. Influence of sex has been investigated in other surgical procedures but has not yet been studied in adult spinal deformity surgery. Methods. The American College of Surgeons National Surgical Quality Improvement Program is a large multicenter clinical registry that prospectively collects preoperative risk factors, intraoperative variables, and 30-day postoperative morbidity and mortality outcomes from about 400 hospitals nationwide. Current Procedural Terminology codes were used to query the database for adults who underwent fusion for spinal deformity. Patients were separated into groups of male and female sex. Univariate analysis and multivariate logistic regression were used to analyze the effect of sex on the incidence of postoperative morbidity and mortality. Results. Female sex was found to be a predictor of any complication[odds ratio (OR): 1.4, 95% confidence interval (CI) 1.2–1.7, P < 0.0001], intra- or postoperative RBC transfusion (OR: 1.6, 95% CI 1.4–1.9, P < .0001), urinary tract infection (OR: 2.0, 95% CI 1.2–3.3, P = 0.0046), and length of stay >5 days (OR: 1.3, 95% CI 1.1–1.5, P = 0.0015). Male sex was associated with higher rate of pulmonary (2.9% vs. 2.0%, P = 0.0344) and cardiac complications (0.9% vs. 0.5%, P = 0.0497). However, male sex as an independent risk factor for pulmonary (OR: 1.4, 95% CI 1.0–2.1, P = 0.0715) and cardiac complications (OR: 1.9, 95% CI 0.9–4.0, P = 0.1076) did not reach significance. Conclusion. Female sex was found to increase overall morbidity, particularly for urinary tract infection, transfusion, and length of stay >5 days. Male sex was associated with greater incidence of pulmonary and cardiac complications. Thus, sex and other patient characteristics highlighted must be considered as part of surgical risk planning and patient counseling. Level of Evidence: 3

Impact of Resident Involvement on Morbidity in Adult Patients Undergoing Fusion for Spinal Deformity

Study Design. A retrospective study of prospectively collected data. Objective. The aim of this study was to determine whether patients undergoing spinal deformity surgery with resident involvement are at an increased risk of morbidity. Summary of Background Data. Resident involvement has been investigated in other orthopedic procedures but has not been studied in adult spinal deformity surgery. Methods. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) is a large multicenter clinical registry that prospectively collects preoperative risk factors, intraoperative variables, and 30-day postoperative morbidity and mortality outcomes from about 400 hospitals nationwide. Current procedural terminology (CPT) codes were used to query the database for adults who underwent fusion for spinal deformity between 2005 and 2012. Patients were separated into propensity score matched groups of those with and without resident involvement. Univariate analysis and multivariate logistic regression were used to analyze the effect of resident involvement on the incidence of postoperative morbidity and other surgical outcomes. Results. Resident involvement was an independent predictor of overall morbidity [odds ratio (OR) 2.2, P < 0.0001], wound complication (OR 2.5, P = 0.0252), intra-/postoperative transfusion (OR 2.3, P < 0.0001), and length of stay > 5 days (OR 2.0, P < 0.0001). However, resident involvement was not an independent predictor for other complications, such as mortality. Conclusion. Resident participation was associated with significantly longer operative times. As a result, higher rate of certain morbidity, but not mortality, was found, specifically for complications that have been previously associated with long operative duration. Level of Evidence: 3

The 100 Most Influential Articles in Cervical Spine Surgery

Study Design Literature review. Objective To identify and analyze the top 100 cited articles in cervical spine surgery. Methods The Thomson Reuters Web of Knowledge was searched for citations of all articles relevant to cervical spine surgery. The number of citations, authorship, year of publication, journal of publication, country of publication, and institution were recorded for each article. Results The most cited article was the classic from 1991 by Vernon and Mior that described the Neck Disability Index. The second most cited was Smiths 1958 article describing the anterior cervical diskectomy and fusion procedure. The third most cited article was Hilibrands 1999 publication evaluating the incidence, prevalence, and radiographic progression of symptomatic adjacent segment disease following anterior cervical arthrodesis. The majority of the articles originated in the United States (65), and most were published in Spine (39). Most articles were published in the 1990s (34), and the three most common topics were cervical fusion (17), surgical complications (9), and biomechanics (9), respectively. Author Abumi had four articles in the top 100 list, and authors Goffin, Panjabi, and Hadley had three each. The Department of Orthopaedic Surgery at Hokkaido University in Sapporo, Japan, had five articles in the top 100 list. Conclusion This report identifies the top 100 articles in cervical spine surgery and acknowledges those individuals who have contributed the most to the advancement of the study of the cervical spine and the body of knowledge used to guide evidence-based clinical decision making in cervical spine surgery today.

The Impact of Resident Involvement in Elective Posterior Cervical Fusion

Study Design. Retrospective study of prospectively collected data Objective. The aim of this study was to assess the impact of resident surgeon involvement on patient outcomes following posterior cervical fusion (PCF) surgery. Summary of Background Data. Recently, there has been a significant uptrend in the number of PCF performed in the United States. Prior studies have investigated patient outcomes after cervical arthrodesis. Despite the heightened concern for patient safety and quality improvement, the data on the safety of resident participation in PCF is sparse. Methods. The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) was examined from 2005 to 2012. Current Procedural Terminology codes were used to query the database for adults (≥18 years) who underwent PCF. Multivariate logistic regression models were employed on data adjusted by propensity scores to determine whether resident involvement was an independent predictor for the outcomes of interest. Results. A total of 448 cases were assessed in NSQIP. Less than half of these cases involved residents (224, 43.1%). Resident involvement was found to be a significant predictor for blood transfusions [odds ratio (OR) = 1.7, confidence interval (CI) = 1.1–2.6, P = 0.010], length of stay of more than 5 days (OR = 1.6, CI = 1.0–2.6, P = 0.040), and operative time more than 4 hours (OR = 3.6, CI = 1.7–7.4, P = 0.0007). Other independent risk factors for prolonged length of stay included age 81 years or older versus 50 years or younger (OR = 4.7, CI = 1.7–12.6, P = 0.016) and diabetes (OR = 2.3, CI = 1.3–4.1, P = 0.006). In addition, multifusion was identified as a significant risk factor for extended operative time (OR = 1.8, CI = 1.1–2.9, P = 0.023). Conclusion. The present study used a large, nationwide sample to assess the impact of resident involvement in PCF. Resident participation was not associated with mortality, but had a minimal association with morbidity. Level of Evidence: 3

Surgical Morbidity and Mortality Associated With Transoral Approach to the Cervical Spine.

Study Design. A retrospective cohort analysis of prospectively collected data. Objective. The aim of this study was to analyze morbidity and mortality in adult patients undergoing transoral approach using a large national database. Summary of Background Data. The transoral approach to the anterior skull base and atlanto-axial cervical spine provides a direct corridor to the lower clivus, C1, C2, and occasionally C3. Due to the rarity of this approach and the unfamiliar anatomy, there is potential for significant morbidity and mortality. Methods. Adult patients undergoing transoral approach to the cervical spine from 2008 to 2012 were identified by the Current Procedural Terminology (CPT) code 22548 in the ACS NSQIP database. Cases with missing preoperative information were excluded. Univariate and multivariate analyses were performed to assess associated morbidity and mortality. Results. One hundred twenty-six patients underwent cervical spine and clival surgery via the transoral approach. There were a total of 27 (21.4%) postoperative complications with three (2.4%) mortalities. On multivariate analysis, there was an increased risk of complications with operative time >4 hours [odds ratio (OR) 7.8, 95% confidence interval (95% CI) 1.8–33.1, P = 0.0054] and total length of stay >5 days (OR 7.5, 95% CI 2.4–23.4, P = 0.0006). Conclusion. The transoral approach carries significant risks of morbidity and mortality. Maintaining operative time <4 hours and LOS <5 days may decrease morbidity and mortality. Level of Evidence: 4

Frailty Is Predictive of Adverse Postoperative Events in Patients Undergoing Lumbar Fusion

Study Design: Retrospective study of prospectively collected data. Objective: To analyze the modified frailty index (mFI) as a predictor of adverse postoperative events following posterior lumbar fusion. Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database including all adult patients undergoing posterior lumbar interbody fusion or transforaminal lumbar interbody fusion between 2005 and 2012. Outcomes measured included mortality, postoperative complications, length of stay, reoperations, and readmissions. The previously described mFI was calculated, and univariate and multivariate logistic regression analysis were used to analyze risk factors associated with morbidity, mortality, and adverse postoperative events. This study was qualified as exempt by the Mount Sinai Hospital Institutional Review Board. Results: A total of 6094 patients met inclusion criteria. The mean mFI was 0.087(0-0.545). Increasing mFI score was associated with increased complications, reoperations, prolonged length of stay (LOS), and morbidity (P < .05). As the mFI score increased from 0.27 (3/11 variables present) to ≥0.36 (4/11), the rate of any complication increased from 26.8% to 35% (P < .0001), sepsis 2.4% to 5.2% (P < .0001), wound complications 4.4% to 6.5% (P < .0001), unplanned readmissions 4.7% to 20% (P = .02), and urinary tract infection 4.1% to 10.4% (P < .0001). An mFI of ≥0.36 was an independent predictor of any complication (odds ratio [OR]= 2.2, 95% confidence interval [CI] = 1.3-3.7), sepsis (OR = 6.3, 95%, CI = 1.8-21), wound complications (OR = 2.9, 95% CI = 1.1-8.2), prolonged LOS (OR = 2.3, 95% CI = 1.4-3.7), and readmission (OR = 4.3, 95% CI = 1.5-12.7). Conclusion: Patients with higher mFI scores (≥ 4/11 variables) are at a significantly higher risk of major complications, readmissions, and prolonged LOS following lumbar fusion.

Incidence, Impact, and Risk Factors for 30-Day Wound Complications Following Elective Adult Spinal Deformity Surgery:

Study Design: Case-control study. Objective: To determine the incidence, impact, and risk factors for wound complications within 30 days following elective adult spinal deformity surgery. Methods: Current Procedural Terminology and International Classification of Diseases, Ninth Edition, diagnosis codes were used to query the database for adults who underwent spinal deformity surgery from 2010 to 2014. Patients were separated into groups of those with and without wound complications. Univariate analysis and multivariate logistic regression were used to analyze the influence of patient factors, operative variables, and clinical characteristics on the incidence of postoperative wound complication. This study was qualified as exempt by the Mount Sinai Hospital Institutional Review Board. Results: A total of 5803 patients met the criteria for this study. Wound complications occurred in 140 patients (2.4%) and were significantly associated with other adverse outcomes, including higher rates of unplanned reoperation (P < .0001) and prolonged length of stay (P < .0001). Regardless of fusion length, wound complication rates were higher with a posterior approach (short = 2.7%; long = 3.7%) than an anterior one (short = 2.2%; long = 2.7). According to the multivariate analysis, posterior fusion (odds ratio [OR] = 1.8; P = .010), obese class II (OR = 1.7; P = .046), obese class III (OR = 2.8; P < .0001), preoperative blood transfusion (OR = 6.1; P = .021), American Society of Anesthesiologists class ≥3 (OR = 1.7; P = .009), and operative time >4 hours (OR = 1.8; P = .006) were statistically significant risk factors for wound complications. Conclusion: The 30-day incidence of wound complication in adult spinal deformity surgery is 2.4%. The risk factors for wound complication are multifactorial. This data should provide a step toward developing quality improvement measures aimed at reducing complications in high-risk adults.

Thirty-Day Morbidity Associated with Pelvic Fixation in Adult Patients Undergoing Fusion for Spinal Deformity: A Propensity-Matched Analysis

Study Design Retrospective study of prospectively collected data. Objective To determine if patients undergoing spinal deformity surgery with pelvic fixation are at an increased risk of morbidity. Methods The American College of Surgeons National Surgical Quality Improvement Program is a large multicenter clinical registry that prospectively collects preoperative risk factors, intraoperative variables, and 30-day postoperative morbidity and mortality outcomes from ~400 hospitals nationwide. Current Procedural Terminology codes were used to query the database between 2010 and 2014 for adults who underwent fusion for spinal deformity. Patients were separated into groups of those with and without pelvic fixation. Univariate analysis and multivariate logistic regression were used to analyze the effect of pelvic fixation on the incidence of postoperative morbidity and other surgical outcomes. Results Multivariate analysis showed that pelvic fixation was a significant predictor of overall morbidity (odds ratio [OR] = 2.3, 95% confidence interval [CI]: 1.7 to 3.1, p = 0.0002), intra- or postoperative blood transfusion (OR = 2.3, 95% CI: 1.7 to 3.1 p < 0.0001), extended operative time (OR = 4.7, 95% CI: 3.1 to 7.0 p < 0.0001), and length of stay > 5 days (OR = 2.1, 95% CI 1.5 to 2.8, p < 0.0001) in patients undergoing fusion for spinal deformity. However, fusion to the pelvis did not lead to additional risk for other complications, including wound complications (p = 0.3191). Conclusion Adult patients undergoing spinal deformity surgery with pelvic fixation were not susceptible to increased morbidity beyond increased blood loss, greater operative time, and extended length of stay.