Faculty Bibliography

BACKGROUND:The Bundled Payments for Care Improvement initiative was developed to reduce costs associated with total joint arthroplasty through a single payment for all patient care from index admission through a 90-day post-discharge period, including care at skilled nursing facilities (SNFs). The aim of this study is to investigate whether forming partnerships between hospitals and SNFs could lower the post-discharge costs. We hypothesize that institutionally aligned SNFs have lower post-discharge costs than non-aligned SNFs. METHODS:A cohort of 615 elective, primary total hip and knee arthroplasty subjects discharged to an SNF under the Bundled Payments for Care Improvement from 2014 to 2016 were included in our analysis. Patients were grouped into one of the 3 categories of SNF alignment: group 1: non-partners; group 2: agreement-based partners; group 3: institution-owned partners. Demographics, comorbidities, length of stay (LOS) at SNF, and associated costs during the 90-day post-operative period were compared between the 3 groups. RESULTS:Mean index hospital LOS was statistically shortest in group 3 (mean 2.7 days vs 3.5 for groups 1 and 2, P = .001). SNF LOS was also shortest in group 3 (mean 11 days vs 19 and 21 days in groups 2 and 1 respectively, P < .001). Total SNF costs and total 90-day costs were both significantly lower in group 3 compared with groups 1 and 2 (P < .001 for all), even after controlling for medical comorbidities. CONCLUSION/CONCLUSIONS:Institution-owned partner SNFs demonstrated the shortest patient LOS, and the lowest SNF and total 90-day costs, without increased risk of readmissions, compared with other SNFs.

BACKGROUND:For Medicare beneficiaries, hospital reimbursement for nonrevision hip arthroplasty is anchored to either diagnosis-related group code 469 or 470. Under alternative payment models, reimbursement for care episodes is not further risk-adjusted. This study's purpose was to compare outcomes of primary total hip arthroplasty (THA) vs conversion THA to explore the rationale for risk adjustment for conversion procedures. METHODS:All primary and conversion THAs from 2007 to 2014, excluding acute hip fractures and cancer patients, were identified in the National Surgical Quality Improvement Program database. Conversion and primary THA patients were matched 1:1 using propensity scores, based on preoperative covariates. Multivariable logistic regressions evaluated associations between conversion THA and 30-day outcomes. RESULTS:A total of 2018 conversions were matched to 2018 primaries. There were no differences in preoperative covariates. Conversions had longer operative times (148 vs 95 minutes, P < .001), more transfusions (37% vs 17%, P < .001), and longer length of stay (4.4 vs 3.1 days, P < .001). Conversion THA had increased odds of complications (odds ratio [OR] 1.75; 95% confidence interval [CI] 1.37-2.24), deep infection (OR 4.21; 95% CI 1.72-10.28), discharge to inpatient care (OR 1.52; 95% CI 1.34-1.72), and death (OR 2.39; 95% CI 1.04-5.47). Readmission odds were similar. CONCLUSION/CONCLUSIONS:Compared with primary THA, conversion THA is associated with more complications, longer length of stay, and increased discharge to continued inpatient care, implying greater resource utilization for conversion patients. As reimbursement models shift toward bundled payment paradigms, conversion THA appears to be a procedure for which risk adjustment is appropriate.

BACKGROUND: Irrigation and debridement with modular component and liner exchange (IDLE) is a low morbidity procedure for treatment of periprosthetic joint infection (PJI) with reported failure rates exceeding 50%. Dilute povidone-iodine lavage has been shown to be safe and effective in decreasing acute PJI in primary total joint arthroplasty. Vancomycin powder has also shown to be effective in preventing infection in spine surgery. We hypothesize that a vancomycin povidone-iodine protocol (VIP) used in conjunction with IDLE can increase infection-free survivorship after acute PJI. METHODS: This is a single institution retrospective review of all PJIs treated with IDLE and VIP since March 2014. A consecutive matched control group of patients treated with IDLE for PJI for 2 years prior to March 2014 was also included for analysis. Primary outcome was failure, defined as return to operating room for an infection-related problem. Secondary outcome was chronic suppression with antibiotics at final follow-up. Minimum follow-up was 1 year. RESULTS: A total of 36 patients in the VIP group and 38 patients in control group were identified. In the VIP group, 16.7% (6/36) failed at final follow-up compared to 37% failure rate (14/38) in the control group (P < .05). Three patients in the VIP group were on chronic antibiotic suppression at final follow-up. There were no medical complications secondary to the VIP. CONCLUSIONS: The VIP group demonstrated a significant reduction in reinfection and failure rate following IDLE. The authors believe that a VIP is an effective adjunct for treating PJI with irrigation and debridement.

BACKGROUND: Bariatric surgery is frequently recommended prior to total joint arthroplasty (TJA) for morbidly obese patients with end-stage arthropathy. Current published data on the efficacy of bariatric surgery for preoperative medical optimization has yielded mixed results, and the effect of time from bariatric surgery to TJA on the preoperative risk profile is not well defined. Our study evaluated the effect of time from bariatric surgery to TJA on 90-day complication and readmission rates. METHODS: We utilized the Healthcare Cost and Utilization Project (HCUP) California State Inpatient Database (SID) to identify patients who underwent TJA following bariatric surgery between 2007 and 2011. Primary endpoints were 90-day complication rates and all-cause 90-day readmission rates following TJA. RESULTS: We identified 330 cases of bariatric surgery followed by total hip arthroplasty (THA) and 1017 cases followed by total knee arthroplasty (TKA). There were no significant demographic differences among patients who underwent TJA greater than or less than 6 months after bariatric surgery. Patients undergoing THA more than 6 months after bariatric surgery were significantly less likely to be readmitted within 90 days for any cause. There was no association between time from bariatric surgery to THA or TKA and 90-day complications. DISCUSSION: Delaying THA at least 6 months after bariatric surgery may help reduce the rate of 90-day readmissions in this high-risk patient population. Arthroplasty surgeons recommending bariatric surgery as preoperative risk modification should consider the patient's overall nutritional status, medical comorbidities, and overall response to surgery prior to booking for TJA.

BACKGROUND: High body mass index (BMI) is associated with significant complications in patients undergoing total joint arthroplasty. Many studies have evaluated this trend, but few have looked at the rates of complications based on BMI as a continuous variable. The purpose of this study was to stratify obese patients into 3 BMI categories and evaluate their rates of complications and gauge whether transitioning from higher to lower BMI category lowers complication. METHODS: Patients undergoing primary total joint arthroplasty were selected from the National Surgical Quality Improvement Program database from 2008-2015 and arranged into 3 groups based on BMI: O1 (BMI 30-34.9 kg/m2), O2 (BMI 35-39.9 kg/m2), and O3 (BMI >40 kg/m2). Thirty-day complications were recorded and evaluated utilizing univariate and multivariate analyses stratified by BMI. RESULTS: A total of 268,663 patients were identified. Patients with a BMI >30 kg/m2 had more infectious and medical complications compared with nonobese patients. Furthermore, there were increased complications as the BMI categories increased. Patients with a BMI >40 kg/m2 (O3) had longer operating times, length of stay, higher rates of readmissions, reoperations, deep venous thrombosis, renal insufficiency, superficial infections, deep infections, and wound dehiscence. These trends were present when comparing the O2 with O1 category as well. CONCLUSION: We have demonstrated increased rates of medical and surgical complications in obese patients. Furthermore, we demonstrated a stepwise increase in complication rates when transitioning to higher BMI groups. Based on our data, we believe that preoperative counseling and interventions to decrease BMI should be explored before offering elective surgery to obese patients.

BACKGROUND: With the establishment of the Hospital Value-Based Purchasing program, the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) score has been incorporated into the calculation of the total performance score, which determines redistribution of up to 2% of Medicare payments. This study aims to assess whether the HCAHPS score correlates with validated outcome measures after total hip arthroplasty. METHODS: Data from 63 patients who underwent a total hip arthroplasty and completed both an HCAHPS score and patient-reported outcome measures (PROMs) at our institution during the study period from January 1, 2015 to September 2016 were analyzed. The HCAHPS overall hospital rating scores were correlated with the preoperative to postoperative change in validated PROMs, namely EuroQol-EQ-5D Instrument and Hip Disability and Osteoarthritis Outcome Score. RESULTS: There was no statistically significant correlation between the HCAHPS overall hospital rating score and PROMs. CONCLUSION: This study shows a lack of correlation between established validated PROMs used in orthopedic surgery, and the HCAHPS survey scores, an important determinant of compensation in the pay-for-performance reimbursement models.

BACKGROUND: Compared to total knee arthroplasty (TKA) for primary osteoarthritis, conversion TKAs in the post-traumatic setting are associated with increased operative times, infection rates, and readmissions. We aim at determining how post-traumatic osteoarthritis and previous knee surgery influence postoperative outcomes in conversion TKA. METHODS: Seventy-two conversion TKA procedures with prior knee trauma at a single institution between April 2012 and 2016 were examined. Twenty-seven (37.5%) cases had a preoperative site-specific diagnosis such as fracture of the proximal tibia, distal femur, or patella whereas 45 (62.5%) cases had a preoperative diagnosis of significant soft-tissue trauma. These 2 groups were compared in terms of total implant cost, length of stay, complications, and readmission and reoperation rates. A subanalysis was conducted to evaluate the effects of previous knee surgery on surgical outcomes. RESULTS: The postfracture TKA cohort suffered significantly higher early surgical site complications (22% vs 4.4%, P = .02) and 90-day readmissions (14.8% vs 2.2%, P = .042) compared to the soft-tissue trauma cohort. Operative time, total implant costs, length of stay, medical complications, 30-day readmissions, and 90-day reoperation rates did not significantly differ. It was also found that patients with multiple prior knee surgeries compared to one prior knee surgery are younger (53.0 vs 63.1, P = .003), healthier, and receive significantly more expensive implants (1.72 vs 1.07, P = .026). In addition, patients with previous open reduction internal fixations experience more surgical site complications than patients with previous arthroscopies (31% vs 3.3%, P = .042). CONCLUSION: Patients with previous site-specific fracture are more likely to experience surgical site complications and 90-day readmissions after conversion TKA than patients with previous soft-tissue knee trauma. Multiple previous knee surgeries appear to serve as an independent factor in the selection of costlier implants irrespective of preoperative diagnosis.

INTRODUCTION: Maintaining accuracy of component placement is an important step in ensuring the long-term stability of components during total hip arthroplasty (THA). Computer-assisted navigation has improved accuracy but errors associated with the registration process are known to impact the accuracy of final measurements. The purpose of this cadaver study was to determine the registration error associated with a novel mini-navigation system. METHODS: 3 board-certified orthopaedic surgeons performed 4 THA procedures each via the posterolateral approach on 6 cadavers (12 hips) using the mini-navigation tool. Pre- and post-operative radiographs and post-operative computed tomography (CT) images were obtained. Image analysis was performed by 2 radiologists not involved in the surgical procedures. During registration, surgeons aligned the alignment rod with the anterior pelvic plane (APP) to provide a reference plane for comparison with traditional navigation. Cup position from the device was compared with measurements gathered from post-op imaging. RESULTS: The mean difference between CT and device measurements for inclination was -1.7 degrees (standard deviation [SD] 4.9 degrees ), while the mean absolute difference was 4.2 degrees (SD 3.2 degrees ). The mean difference between anteversion angles calculated from CT scans and from the device was -3.5 degrees (SD 4.5 degrees ), with an absolute difference of 4.0 degrees (SD 4.0 degrees ). 100% (12/12) of inclination measurements and 92% (11/12) of anteversion measurements fell within both the clinical and statistical limits of agreement when analyzed via the Bland-Altman technique. CONCLUSIONS: This study demonstrates that the registration error associated with this new mini-navigation system compares favourably with the known registration error associated with traditional navigation systems.

BACKGROUND: Chronic opioid users pose a unique challenge for orthopedic surgeons, as they often report suboptimal outcomes following total knee arthroplasty (TKA). We aim at identifying risk factors associated with patients who were preoperative chronic opioid users and continued to use 6 months following TKA. METHODS: All preoperative chronic opioid users among 338 consecutive TKA cases performed at our institution between February and June 2016 were identified and divided into 2 cohorts: patients who (1) persistently used opioids and (2) discontinued use by the 6-month time point following surgery. Baseline characteristics were compared between cohorts in order to determine risk factors for persistent opioid use following TKA. RESULTS: Of the 338 patients, 53 (15.7%) were identified as preoperative chronic opioid users. Of these, 23 (43.4%) continued chronic opioid use 6 months following surgery, whereas 14 (4.9%) previously nonchronic users were identified as new chronic users at 6 months. Characteristics that were predictive of persistent opioid use included male gender, prior injury or surgery to the ipsilateral knee, current tobacco smoking status, and a history of psychiatric disorder. Opioid dose consumption of >/=12 mg/d morphine-equivalents over the 3 months leading up to surgery had an increased risk of persistent chronic opioid use by a factor of 6. CONCLUSION: TKA candidates who have complicated medical, social, and surgical histories are at an increased risk of chronic opioid abuse postoperatively. By better understanding the risk factors associated with persistent chronic opioid use, targeted opioid reduction programs may be appropriately implemented to manage this high-risk population.

Background/UNASSIGNED:As medical management continues to improve, orthopaedic surgeons are likely to encounter a greater proportion of patients who have coinfection with human immunodeficiency virus (HIV) and hepatitis-C virus (HCV). Methods/UNASSIGNED:The New York Statewide Planning and Research Cooperative System (SPARCS) database was used to identify patients undergoing total knee arthroplasty between 2010 and 2014. Patients were stratified into 4 groups on the basis of HCV and HIV status. Differences regarding baseline demographics, length of stay, total charges, discharge disposition, in-hospital complications and mortality, and 90-day hospital readmission were calculated. Results/UNASSIGNED:Between 2010 and 2014, a total of 137,801 patients underwent total knee arthroplasty. Of those, 99.13% (136,604) of the population were not infected, 0.62% (851) had HCV monoinfection, 0.20% (278) had HIV monoinfection, and 0.05% (68) were coinfected with both HCV and HIV. Coinfected patients were more likely to be younger, female, a member of a minority group, homeless, and insured by Medicare or Medicaid, and to have a history of substance abuse. HCV and HIV coinfection was a significant independent risk factor for increased length of hospital stay (odds ratio [OR], 2.9; 95% confidence interval [CI], 1.75 to 4.81), total hospital charges in the 90th percentile (OR, 2.02; 95% CI, 1.12 to 3.67), ≥2 in-hospital complications (OR, 2.04; 95% CI, 1.04 to 3.97), and 90-day hospital readmission (OR, 3.53; 95% CI, 2.02 to 6.18). Conclusions/UNASSIGNED:Patients coinfected with both HCV and HIV represent a rare but increasing population of individuals undergoing total knee arthroplasty. Recognition of unique baseline demographics in these patients that may lead to suboptimal outcomes will allow appropriate preoperative management and multidisciplinary coordination to reduce morbidity and mortality while containing costs. Level of Evidence/UNASSIGNED:Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.