Faculty Bibliography

BACKGROUND:Patients undergoing multilevel spine surgery are at risk for delayed extubation. OBJECTIVE:To evaluate the impact of type and volume of intraoperative fluids administered during multilevel thoracic and/or lumbar spine surgery on postoperative extubation status. METHODS:Retrospective evaluation of medical records of patients ≥ 18 yr undergoing ≥ 4 levels of thoracic and/or lumbar spine fusions was performed. Patients were organized according to postoperative extubation status: immediate (IMEX; in OR/PACU) or delayed (DEX; outside OR/PACU). Propensity score matched (PSM) analysis was performed to compare IMEX and DEX groups. Volume, proportion, and ratios of intraoperative fluids administered were evaluated for the associated impact on extubation status. RESULTS:A total of 246 patients (198 IMEX, 48 DEX) were included. PSM analysis demonstrated that increased administration of non-cell saver blood products (NCSB) and increased ratio of crystalloid: colloids infused were independently associated with delayed extubation. With increasing EBL, IMEX had a proportionate reduction in crystalloid infusion (R = -0.5, P < .001), while the proportion of crystalloids infused remained relatively unchanged for DEX (R = -0.27; P = .06). Twenty-six percent of patients receiving crystalloid: colloid ratio > 3:1 had DEX compared to none of those receiving crystalloid: colloid ratio ≤ 3:1 (P = .009). DEX had greater cardiac and pulmonary complications, surgical site infections and prolonged intensive care unit and hospital stay (P < .05). CONCLUSION/CONCLUSIONS:PSM analysis of patients undergoing multilevel thoracic and/or lumbar spine fusion demonstrated that increased administration of crystalloid to colloid ratio is independently associated with delayed extubation. With increasing EBL, a proportionate reduction of crystalloids facilitates early extubation.

Interest in the application of bundled payments to the field of spine surgery continues to grow. There may be great potential for cost-savings for spinal procedures under bundled payments. However, challenges such as heterogeneity of DRGs, complex procedures requiring lengthy recoveries, and appropriate outcomes measurement pose barriers to successful bundled payment design. In this paper, we review the challenges and opportunities posed by bundled payments in spine surgery. We also present several key considerations for policymakers interested in payment reform within spine surgery. Surgeon involvement will be critical in providing guidance for generating effective alternative payment models.

Background/UNASSIGNED:Spinal fusion surgery is performed about half a million times per year in the United States and millions more worldwide. It is an effective method for reducing pain, increasing stability, and correcting deformity in patients with various spinal conditions. In addition to being a well-established risk factor for a variety of medical conditions, smoking has deleterious effects on the bone healing of spinal fusions. This review aims to specifically analyze the ways in which smoking affects the outcomes of spinal fusion and to explore ways in which these negative consequences can be avoided. Purpose/UNASSIGNED:This article provides a complete understanding of the ways smoking affects spinal fusion from a biochemical and clinical perspective. Recommendations are also provided for ways in which surgeons can limit patient exposure to the most serious negative outcomes associated with cigarette smoking. Study Design/Setting/UNASSIGNED:This study was a retrospective literature review done using the NCBI database. The research was compiled at NYU Hospital for Joint Diseases and the NYU Center for Musculoskeletal Care. Methods/UNASSIGNED:A comprehensive literature review was done spanning research on a variety of subjects related to smoking and spinal fusion surgery. The biochemistry of smoking and fusion healing were examined in great detail. In addition, both in vivo animal studies and human clinical studies were evaluated to explore fusion success related to the effects of smoking and its biochemical factors on spinal fusion surgery. Results/UNASSIGNED:Smoking significantly increases the risk of pseudoarthrosis for patients undergoing both lumbar and cervical fusions. In addition to nonunion, smoking also increases the risk of other perioperative complications such as infection, adjacent-segment pathology, and dysphagia. Treatment options are available that can be explored to reduce the risk of smoking-related morbidity, such as nicotine replacement therapy and use of bone morphogenetic proteins (BMPs). Conclusions/UNASSIGNED:It has been clearly demonstrated from both a biochemical and clinical perspective that smoking increases the rate of perioperative complications for patients undergoing spinal fusion surgery, particularly pseudoarthosis. It has also been shown that there are certain approaches that can reduce the risk of morbidity. The most important recommendation is smoking cessation for four weeks after surgery. In addition, patients may be treated with certain surgical techniques, including the use of BMPs, to reduce the risk of pseudoarthrosis. Lastly, nicotine replacement therapy is an area of continued interest in relation to spinal fusion outcomes and more research needs to be done to determine its efficacy moving forward.

INTRODUCTION: Orthopaedic care is shifting to alternative payment models. We examined whether New York University Langone Medical Center achieved savings under the Centers for Medicare and Medicaid Services Bundled Payments for Care Improvement initiative. METHODS: This study was a difference-in-differences study of Medicare fee-for-service patients hospitalized from April 2011 to June 2012 and October 2013 to December 2014 for lower extremity joint arthroplasty, cardiac valve procedures, or spine surgery (intervention groups), or for congestive heart failure, major bowel procedures, medical peripheral vascular disorders, medical noninfectious orthopaedic care, or stroke (control group). We examined total episode costs and costs by service category. RESULTS: We included 2,940 intervention episodes and 1,474 control episodes. Relative to the trend in the control group, lower extremity joint arthroplasty episodes achieved the greatest savings: adjusted average episode cost during the intervention period decreased by $3,017 (95% confidence interval [CI], -$6,066 to $31). For cardiac procedures, the adjusted average episode cost decreased by $2,999 (95% CI, -$8,103 to $2,105), and for spinal fusion, it increased by $8,291 (95% CI, $2,879 to $13,703). Savings were driven predominantly by shifting postdischarge care from inpatient rehabilitation facilities to home. Spinal fusion index admission costs increased because of changes in surgical technique. DISCUSSION: Under bundled payment, New York University Langone Medical Center decreased total episode costs in patients undergoing lower extremity joint arthroplasty. For patients undergoing cardiac valve procedures, evidence of savings was not as strong, and for patients undergoing spinal fusion, total episode costs increased. For all three conditions, the proportion of patients referred to inpatient rehabilitation facilities upon discharge decreased. These changes were not associated with an increase in index hospital length of stay or readmission rate. CONCLUSION: Opportunities for savings under bundled payment may be greater for lower extremity joint arthroplasty than for other conditions.

BACKGROUND: Recent studies show increases in cervical spine surgery prevalence and cervical spondylotic myelopathy (CSM) diagnoses in the US. However, few studies have examined outcomes for CSM surgical management, particularly on a nationwide scale. OBJECTIVE: Evaluate national trends from 2001 to 2010 for CSM patient surgical approach, postoperative outcomes, and hospital characteristics. METHODS: A retrospective nationwide database analysis provided by the Nationwide Inpatient Sample (NIS) including CSM patients aged 25+ who underwent anterior and/or posterior cervical fusion or laminoplasty from 2001 to 2010. Patients with fractures, 9+ levels fused, or any cancer were excluded. Measures included demographics, hospital data, and procedure-related complications. Yearly trends were analyzed using linear regression modeling. RESULTS: 54,348 discharge cases were identified. ACDF, posterior only, and combined anterior/posterior approach volumes significantly increased from 2001 to 2010 (98.62%, 303.07%, and 576.19%; respectively, p<0.05). However, laminoplasty volume remained unchanged (p>0.05). Total charges for ACDF, posterior only, combined anterior/posterior, and laminoplasty approaches all significantly increased (138.72%, 176.74%, 182.48%, and 144.85%, respectively; p<0.05). For all procedures, overall mortality significantly decreased by 45.34% (p=0.001) and overall morbidity increased by 33.82% (p=0.0002). For all procedures except ACDF, which saw a significantly decrease by 8.75% (p<0.0001), length of hospital stay was unchanged. CONCLUSIONS: For CSM patients between 2001 and 2010, combined surgical approach increased sixfold, posterior only approach increased threefold, and ACDF doubled; laminoplasties without fusion volume remained the same. Mortality decreased whereas morbidity and total charges increased. Length of stay decreased only for ACDF approach. This study provides clinically useful data to direct future research, improving patient outcomes.

OBJECTIVES: The purpose of this study was to evaluate the relationship between the Risk Assessment and Predictor Tool (RAPT) and patient discharge disposition in an institution participating in bundled payment program for total joint replacement, spine fusion and cardiac valve surgery patients. METHOD: Between April 2014 and April 2015, RAPT scores of 767 patients (535 primary unilateral total joint arthroplasty; 150 cardiac valve replacement; 82 spinal fusions) were prospectively captured. Total RAPT scores were grouped into three levels for risk of complications: <6='high risk', between 6 and 9 ='medium risk', and >9='low risk' for discharge to a post-acute facility. Associations between RAPT categories and patient discharge to home versus any facility were conducted. Multivariate analysis was performed to determine if there was any correlation between RAPT score and discharge to any facility. RESULTS: 70.5% of total joint patients, 80.7% of cardiac valve surgery patients and 70.7% of spine surgery patients were discharged home rather than to a post-acute facility. RAPT risk categories were related to discharge disposition as 72% of those in the high risk group were discharged to a facility and 91% in the low risk group were discharged to home in the total joint replacement cohort. In the cardiac cohort, only 33% of the high risk group was discharged to a facility, and 94% of the low risk group was discharged to home. In the spinal fusion cohort, 60% of those in the high risk group were discharged to a facility and 86% in the low risk group were discharged to home. Multivariate analysis showed that being in the high risk category versus low risk category was significantly associated with substantially increased odds of discharge to a facility. CONCLUSION: The RAPT tool has shown the ability to predict discharge disposition for total joint and spine surgery patients, but not cardiac valve surgery patients, where the majority of patients in all categories were discharged home, at an institution participating in a bundled payment program. The ability to identify discharge disposition pre-operatively is valuable for improving care coordination, directing care resources and establishing and maintaining patient and family expectations.

OBJECTIVES: The purpose of this study was to determine the cost/quality-adjusted life-year (QALY) of the operative treatment of lumbar spondylolisthesis and identify factors associated with cost-effectiveness at 2 years. METHODS: We evaluated patients who underwent surgery for spondylolisthesis. The QALY was determined from the EQ5D. Outcomes were also assessed using the Oswestry Disability Index (ODI). Surgical, neuromonitoring, and anesthesia Current Procedural Terminology (CPT) codes as well as hospital Diagnosis-Related Group codes were used to determine the Medicare direct care costs of surgery. Indirect costs were modeled based on existing literature. A discounting rate of 3% was applied. Analysis was performed to determine which factors were associated with a cost/QALY less than $100,000. RESULTS: There were 44 patients who underwent surgery for either degenerative (30) or isthmic spondylolisthesis (14). There were 27 women and 17 men, with an average age at surgery of 59.7 years (standard deviation [SD] = 14.69) and an average follow-up of 2 years (SD = 0.82). The average postoperative improvement in ODI was 24.77 (SD = 23.9), and change in QALY was 0.43 (SD = 0.30). The average cost/QALY at 2 years for direct care costs was $89,065. The average cost/QALY at 2 years for direct plus indirect costs was $112,588. Higher preoperative leg pain and greater leg pain change was associated with a cost/QALY <$100,000 (p < .005, p < .028). The cost-effective group had a higher proportion of patients with disease extent of two or more levels (p = .021). When comparing surgical techniques of anterior-posterior and posterior only, there was no difference in cost-effectiveness. CONCLUSIONS: Spondylolisthesis surgery is cost-effective at 2 years, with a QALY change of 0.43 and a direct cost/QALY of $89,065. Higher preoperative leg pain and larger extent of disease was associated with cost-effectiveness. LEVEL OF EVIDENCE: IV.

INTRODUCTION: Wound infections following spinal surgery place a high toll on both the patient and the healthcare system. Although several large series studies have examined the incidence and distribution of spinal wound infection, the applicability of these studies varies greatly since nearly every study is either retrospective and/or lacks standard inclusion criteria for defining surgical site infection. To address this void, we present results from prospectively gathered thoracolumbar spine surgery data for which the Centers for Disease Control (CDC) criteria were stringently applied to define a surgical site infection (SSI). METHODS: A prospective randomized trial of 314 patients who underwent multilevel thoracolumbar spinal surgery with instrumentation followed by postoperative drain placement was completed (Takemoto et al., 2015). The trial consisted of two antibiotic arms: one for 24-hours, and the other for the duration of the drain; no differences were found between the arms. All infections meeting CDC criteria for SSI were included. RESULTS: A total of 40 infections met CDC criteria for SSI, for an overall incidence of 12.7%. Of these, 20 (50%) were culture-positive. The most common organism was Staphylococcus aureus (4 total: methicillin-sensitive=2; methicillin-resistant=2), followed by coagulase-negative Staphylococcus (3 cases), Propionibacterium acnes and Escherichia coli (2 cases each). Six infections grew multiple organisms, most commonly involving coagulase-negative staphylococcus and enterococcus. CONCLUSIONS: Our findings indicate that thoracolumbar SSI occurs at the higher end of the range cited in the literature (2-13%), which is largely based on retrospective data not subjected to the inclusivity of SSI as defined by the CDC. The three most common organisms in our analysis (S. aureus, P. acnes, E. coli) are consistent with previous reports. Staphylococcus aureus continues to be the most common causative organism and continued vigilance and searching for preventive measures need to be a high priority. This study provides Level I evidence.

BACKGROUND CONTEXT: Degenerative lumbar stenosis (DLS) patients have been reported to lean forward in an attempt to provide neural decompression. Spinal alignment in patients with DLS may resemble that of adult spinal deformity (ASD). No previous studies have compared and contrasted the compensatory mechanisms of DLS and ASD patients. PURPOSE: To determine the differences in compensatory mechanisms between DLS and ASD patients with increasing severity of sagittal spino-pelvic malalignment. Contrasting these compensatory mechanisms may help determine at what severity sagittal malalignment represents a clinical sagittal deformity rather than a compensation for neural compression. STUDY DESIGN/SETTING: Retrospective clinical and radiological review PATIENT SAMPLE:: Baseline x-rays in patients without spinal instrumentation, with the clinical radiological and diagnoses of DLS or ASD were assessed for patterns of spino-pelvic compensatory mechanisms. Patients were stratified by sagittal vertical axis (SVA) by the Schwab-SRS classification. OUTCOME MEASURES: Radiographic spino-pelvic parameters were measured in the DLS and ASD groups, including SVA, PI-LL, T1SPi, TPA and PT METHODS: The two diagnosis cohorts were propensity matched for pelvic incidence and age. Each group contained 125 patients. Each group was stratified according to the SRS-Schwab classification. Regional spino-pelvic, lower limb and global alignment parameters were assessed in each group to identify differences in compensatory mechanisms between the two groups with differing degrees of deformity. No funding was provided by any third party in relation to carrying out this study or preparation of the manuscript. RESULTS: With mild to moderate malalignment (SRS-Schwab groups '0', or '+' for pelvic tilt, pelvic incidence-lumbar lordosis mismatch or sagittal vertical axis), DLS patients permit anterior truncal inclination and recruit posterior pelvic shift instead of pelvic tilt to maintain balance, while providing relief of neurological symptoms. ASD patients with mild- moderate deformity recruit pelvic tilt earlier than DLS patients. With moderate- severe malalignment, no significant difference was found in compensatory mechanisms between DLS and ASD patients. CONCLUSIONS: Patients with degenerative lumbar stenosis permit mild-moderate deformity without recruiting compensatory mechanisms of pelvic tilt, reducing truncal inclination and thoracic hypokyphosis in order to achieve neural decompression. However with moderate to severe deformity, their desire for upright posture overrides the desire for neural decompression, evident by the adaptation of compensatory mechanisms similar to that of the adult spinal deformity patients.