Bundled Payment in Total Joint Care: Survey of AAHKS Membership Attitudes and Experience with Alternative Payment Models

Improved outcomes with perioperative dietitian-led interventions in patients undergoing total joint arthroplasty: A systematic review

Background

Nutritional assessment is important for optimization of patients undergoing elective total joint arthroplasty (TJA). Preoperative nutritional intervention is a potentially modifiable optimization target, but the outcomes of such intervention are not well-studied. The purpose of this study is to assess the impact of nutritional interventions on elective TJA outcomes.

Methods

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were utilized to perform a systematic review of the Ovid Medline, Embase, and Cochrane Library systems. Included studies were comprised of patients greater than 18 years of age undergoing a primary unilateral TJA who received a perioperative dietitian-led intervention. Data analyzed included nutritional intervention protocol, patient demographics, length of stay (LOS), postoperative labs and complications, among others.

Results

Our initial search identified a total of 1766 articles. Four studies representing 5006 patients met inclusion criteria. The studies utilized a protein-dominant diet, with or without a carbohydrate solution accompanied by dietitian assessment or education. The 4 studies found that the intervention group had significantly decreased LOS, fewer albumin infusions, less wound drainage, lower rates of hypocalcemia and hypokalemia, reduced C-reactive protein (CRP) values, improved time out of bed, and decreased overall costs.

Conclusion

The findings support the potential benefits of perioperative dietitian-led intervention on key outcomes for patients undergoing primary TJA. Surgeons should consider nutritional intervention in their preoperative optimization protocols. Future studies could help elucidate the optimum nutritional regimens and monitoring for idealized intervention and surgical timing.

Prospero registration number

CRD4202338494.

A Cautionary Tale: Malaligned Incentives in Total Hip and Knee Arthroplasty Payment Model Reforms Threaten Promising Innovation and Access to Care

Over the past several years, there have been notable changes and controversies involving Medicare reimbursement for total hip (THA) and total knee arthroplasty (TKA). We have seen the development and implementation of experimental bundled payment model pilot programs goals of improving quality and decreasing overall costs of care during the last decade. Many orthopaedic surgeons have embraced these programs and have demonstrated the ability to succeed in these new models by implementing strategies, such as preservice optimization, to shift care away from inpatient or postdischarge settings and reduce postoperative complications. However, these achievements have been met with continual reductions in surgeon reimbursement rates, lower bundle payment target pricings, modest increases in hospital reimbursement rates, and inappropriate valuations of THA and TKA Common Procedural Terminology (CPT) codes. These challenges have led to an organized advocacy movement and spurred research involving the methods by which improvements have been made throughout the entire episode of arthroplasty care. Collectively, these efforts have recently led to a novel application of CPT codes recognized by payers to potentially capture presurgical optimization work. In this paper, we present an overview of contemporary payment models, summarize notable events involved in the review of THA and TKA CPT codes, review recent changes to THA and TKA reimbursement, and discuss future challenges faced by arthroplasty surgeons that threaten access to high-quality THA and TKA care.

Cardiovascular Disease in Total Knee Arthroplasty: An Analysis of Hospital Outcomes, Complications, and Mortality

Background

Cardiovascular comorbidities have been identified as a significant risk factor for adverse outcomes following surgery. The purpose of this study was to investigate its prevalence and impact on postoperative outcomes, hospital metrics, and mortality in patients undergoing total knee arthroplasty (TKA). Our hypothesis was that patients with cardiovascular comorbidities would have worse outcomes, greater postoperative complication rates, and increased mortality compared to patients without cardiovascular disease.

Methods

In this retrospective study, data from the National Inpatient Sample database from 2011 to 2020 were queried for patients who underwent TKA with preexisting cardiac comorbidities, including congestive heart failure (CHF), coronary artery disease (CAD), valvular dysfunction, and arrhythmia. Multivariate logistic regression analyses compared hospital metrics (length of stay, costs, and adverse discharge disposition), postoperative complications, and mortality rates while adjusting for demographic and clinical variables. All statistical analyses were performed using R studio 4.2.2 and Stata MP 17 and 18 with Python package.

Results

A total of 385,585 patients were identified. Those with preexisting CHF, CAD, valvular dysfunction, or arrhythmias were found to be older and at higher risk of adverse outcomes, including prolonged length of stay, increased hospital charges, and increased mortality (p < 0.001). Additionally, all preexisting cardiac diagnoses led to an increased risk of postoperative myocardial infarction, acute kidney injury (AKI), and need for transfusion (p < 0.001). The presence of valvular dysfunction, arrhythmia, or CHF was associated with an increased risk of thromboembolic events (p < 0.001). The presence of CAD and valvular dysfunction was associated with an increased risk of urologic infection (p < 0.001).

Conclusions

This study demonstrated that CHF, CAD, valvular dysfunction, and arrhythmia are prevalent among TKA patients and associated with worse hospital metrics, higher risk of perioperative complications, and increased mortality. As our use of TKA rises, a lower threshold for preoperative cardiology referral in older individuals and early preoperative counseling/intervention in those with known cardiac disease may be necessary to reduce adverse outcomes.

Risk Factors for Increased Hospital Costs for Primary Total Hip Arthroplasty

BACKGROUND

Patient medical complexity increases the cost of primary total hip arthroplasty (THA). The goal of this study was to quantify the impact of specific medical comorbidities on the real hospital cost of primary THA.

METHODS

This study consisted of a retrospective analysis of 1,222 patient encounters for Current Procedural Terminology code 27130 (primary THA) between January 2017 and March 2020 at a high-volume urban academic medical center. Patient demographics, comorbidities, and admission data were collected, and univariate and multivariate gamma regression analyses were performed to identify associations with increased costs incurred during THA admission.

RESULTS

The median total cost for THA was $30,580. Univariate analysis showed increased cost for body mass index (BMI) > 35 versus BMI < 35 ($31,739 versus 30,071; P < .05), American Society of Anesthesiologists (ASA) score 3 to 4 versus ASA 1 to 2 ($32,268 versus 30,045; P < .05), prevalence of diabetes ($31,523 versus 30,379; P < .05), congestive heart failure ($34,814 versus 30,584; P < .05), peripheral vascular disease (PVD) ($35,369 versus 30,573; P < .05), chronic pulmonary disease (CPD) ($34,625 versus 30,405; P < .05), renal disease ($31,973 versus 30,352; P < .05), and increased length of stay (r = 0.424; P < .05). Multivariate gamma regression showed that BMI > 35 (relative risk [RR] = 1.05), ASA 3 to 4 (RR = 1.07), PVD (RR = 1.29), CPD (RR = 1.13), and renal disease (RR = 1.09) were independently associated with increased THA hospital cost (P < .01). Increased costs seen in BMI > 35 versus BMI < 35 patients were largely due to hospital room and board ($6,345 versus 5,766; P = .01) and operating room costs ($5,744 versus 5,185; P < .05).

CONCLUSIONS

A BMI > 35, PVD, CPD, renal disease, and ASA 3 to 4 are associated with higher inpatient hospital costs for THA.

LEVEL OF EVIDENCE

Level III; Retrospective cohort study.

The Financial Burden of Patient Comorbidities on Total Hip Arthroplasties-A Matched Cohort Analysis of High Comorbidity Burden and Non-High Comorbidity Burden Patients

BACKGROUND

The impact of increased patient comorbidities on the cost-effectiveness of total hip arthroplasty (THAs) is lacking. This study aimed to compare revenue, costs, and short-term (90 days) surgical outcomes between patients who have and do not have a high comorbidity burden (HCB).

METHODS

We retrospectively reviewed 14,949 patients who underwent an elective, unilateral THA between 2012 and 2021. Patients were stratified into HCB (Charlson Comorbidity Index ≥ 5 and American Society of Anesthesiology scores of 3 or 4) and non-HCB groups, and were further 1:1 propensity matched based on baseline characteristics. Perioperative data, revenue, costs, and contribution margins (CMs) of the inpatient episode were compared between groups. Also, 90-day readmissions and revisions were compared between groups. Of the 11,717 patients who had available financial data (n = 1,017 HCB, n = 10,700 non-HCB), 1,914 patients were included in the final matched analyses (957 per group).

RESULTS

Total (P < .001) and direct (P < .001) costs were significantly higher for HCB patients. Comparable revenue between cohorts (P = .083) resulted in a significantly decreased CM in the HCB patient group (P < .001). The HCB patients were less likely to be discharged home (P < .001) and had significantly higher 90-day readmission rates (P = .049).

CONCLUSIONS

Increased THA costs for HCB patients were not matched by increased revenue, resulting in decreased CM. Higher rates of nonhome discharge and readmissions in the HCB population add to the additional financial burden. Adjustments to the current reimbursement models should better account for the increased financial burden of HCB patients undergoing THA and ensure access to care for all patient populations.

LEVEL OF EVIDENCE

III.

The reimbursement system can influence the treatment choice and favor joint replacement versus other less invasive solutions in patients affected by osteoarthritis

PURPOSE

The aim of this study was to assess how physicians perceive the role of the reimbursement system and its potential influence in affecting their treatment choice in the management of patients affected by osteoarthritis (OA).

METHODS

A survey was administered to 283 members of SIAGASCOT (Italian Society of Arthroscopy, Knee, Upper Limb, Sport, Cartilage and Orthopaedic Technologies), a National scientific orthopaedic society. The survey presented multiple choice questions on the access allowed by the current Diagnosis-Related Groups (DRG) system to all necessary options to treat patients affected by OA and on the influence toward prosthetic solutions versus other less invasive options.

RESULTS

Almost 70% of the participants consider that the current DRG system does not allow access to all necessary options to best treat patients affected by OA. More than half of the participants thought that the current DRG system favors the choice of prosthetic solutions (55%) and that it can contribute to the increase in prosthetic implantation at the expense of less invasive solutions (54%). The sub-analyses based on different age groups, professional roles, and places of work allowed to evaluate the response in each specific category, confirming the findings for all investigated aspects.

CONCLUSIONS

This survey documented that the majority of physicians consider that the reimbursement system can influence the treatment choice when managing OA patients. The current DRG system was perceived as unbalanced in favor of the choice of the prosthetic solution, which could contribute to the increase in prosthetic implantation at the expense of other less invasive options for OA management.

Distressed communities demonstrate increased readmission and health care utilization following shoulder arthroplasty

BACKGROUND

Socioeconomic status (SES) has been shown to affect outcomes following total shoulder arthroplasty (TSA), but little is known regarding how SES and the communities in which patients reside can affect postoperative health care utilization. With the growing use of bundled payment models, understanding what factors put patients at risk for readmission and the ways in which patients utilize the health care system postoperatively is crucial for preventing excess costs for providers. This study helps surgeons predict which patients are high-risk and may require additional surveillance following shoulder arthroplasty.

METHODS

A retrospective review of 6170 patients undergoing primary shoulder arthroplasty (anatomic and reverse; Current Procedural Terminology code 23472) from 2014-2020 at a single academic institution was performed. Exclusion criteria included arthroplasty for fracture, active malignancy, and revision arthroplasty. Demographics, patient zip code, and Charlson Comorbidity Index were attained. Patients were classified according to the Distressed Communities Index (DCI) score of their zip code. The DCI combines several metrics of socioeconomic well-being to generate a single score. Zip codes are then classified by scores into 5 categories based on national quintiles. The primary outcome of interest was 90-day readmissions. Secondary outcomes included number of postoperative medication prescriptions, patient telephone calls to the office, and follow-up office visits.

RESULTS

Among all patients undergoing total shoulder arthroplasty, individuals from distressed communities were more likely than their prosperous counterparts to experience an unplanned readmission (odds ratio = 1.77, P = .045). Patients from comfortable (relative risk [RR] = 1.12, P < .001), midtier (RR = 1.13, P < .001), at-risk (RR = 1.20, P < .001), and distressed (RR = 1.17, P < .001) communities were all more likely to use more medications compared to those from prosperous communities. Likewise, those from comfortable (RR = 0.92, P < .001), midtier (RR = 0.88, P < .001), at-risk (RR = 0.93, P = .008), and distressed (RR = 0.93, P = .033) communities, respectively, were at a lower risk of making calls compared to prosperous communities.

CONCLUSIONS

Following primary total shoulder arthroplasty, patients who reside in distressed communities are at significantly increased risk of experiencing an unplanned readmission and increased health care utilization postoperatively. This study revealed that patient socioeconomic distress is more associated with readmission than race following TSA. Increased awareness and employing strategies to maintain and ultimately improve communication with patients offers a potential solution to reduce excessive health care utilization, benefiting both patients and providers alike.

Barriers and Facilitators to Health-Care Provider Payment Reform - A Scoping Literature Review

Background

Changes to provider payment systems are among the most common reforms in health care. They are important levers for policymakers to influence the health system performance. The aim of this study was to identify, systematize, and map the existing literature on the factors that influence health-care provider payment reforms.

Methods

A scoping review was conducted. Literature published in English between 2000 and 2022 was systematically searched in five databases, relevant organizations, and journals. Academic publications and grey literature on health-care provider payment reform and the factors influencing reform were considered. An inductive thematic analysis was applied to map the barriers and facilitators that influence payment reforms.

Results

The study included 51 publications. They were divided into four categories: empirical studies (n=17), literature reviews (n=6), discussion/policy papers (n=18), and technical reports/policy briefs (n=9). Most of the studies were conducted in developed economy countries (n=36). The most frequently reformed payment method was fee-for-service (n=37), and the newly implemented methods included bundled payments (n=16), pay-for-performance (n=15), and diagnosis-related groups (n=11). This study identified 43 sub-themes on barriers to provider payment reforms, which were grouped into eight main themes. It identified 51 sub-themes on facilitators, which were grouped into six themes. Barriers include stakeholder opposition, challenges related to reform design, hurdles in implementation structures, insufficient resources, challenges related to market structures, legal barriers, knowledge and information gaps, and negative publicity. Facilitators include stakeholder involvement, complementary reforms/policies, relevant prior experience, good leadership and management of change, sufficient resources, and external pressure to introduce reform.

Conclusion

The factors that influence health-care payment reforms are often contextual and interrelated, and encompass a variety of perspectives, including those of patients, providers, insurers, and policymakers. When planning reforms, one should anticipate potential barriers and devise appropriate interventions.

Registration

The study was registered with the Open Science Framework.

Health Policy Views and Political Advocacy of Arthroplasty Surgeons: A Survey of the American Association of Hip and Knee Surgeons Members

BACKGROUND

The American Association of Hip and Knee Surgeons (AAHKS) is the largest specialty society for arthroplasty surgeons in the United States and is dedicated to education, research, and advocacy. The purpose of this study was to identify the health policy views of AAHKS members and better characterize their advocacy participation.

METHODS

A 22 question survey was electronically distributed multiple times via email link to all 3,638 United States members of AAHKS who were in practice or training in 2022. Study results were analyzed using descriptive statistics.

RESULTS

There were 311 responses (9%), with 18% of respondents being within 5 years of practice and 38% having more than 20 years of practice. Respondents identified as Republicans (40%), Independents (37%), and Democrats (21%). Top policy issues included preserving physician reimbursement and equitable fee schedule representation (95%), the burden of prior authorization (53%), the impact of Center of Medicare and Medicaid Services regulations (39%), and medical liability and tort reform (39%). Members ranked maintaining appropriate physician reimbursement (44%) and advocating for patients (37%) as the top benefits to participation in advocacy. A majority of respondents (81%) stated that they spend more time on presurgery optimization now than 10 years ago. The most common barrier to advocacy participation was a lack of time (77%).

CONCLUSION

Responding AAHKS members are well-informed, politically engaged, patient-oriented, and eager for a voice in policy decisions that affect the professional future of arthroplasty surgeons. These results can be used to help direct strategic efforts of the AAHKS Advocacy Committee to further increase advocacy efforts.

Prior Authorization in Total Joint Arthroplasty: A Survey of the American Association of Hip and Knee Surgeons Membership

BACKGROUND

This study surveyed the impact that prior authorization has on the practices of total joint arthroplasty (TJA) members of the American Association of Hip and Knee Surgeons (AAHKS).

METHODS

A 24-question survey was approved by the AAHKS Advocacy Committee and distributed to all 2,802 board-certified members of AAHKS.

RESULTS

There were 353 survey responses (13%). Ninety-five percent of surgeons noted a 5-year increase in prior authorization. A majority (71%) of practices employ at least 1 staff member to exclusively work on prior authorization. Average time spent on prior authorization was 15 h/wk (range, 1 to 125) and average number of claims peer week was 18 (range, 1 to 250). Surgeries (99%) were the most common denial. These were denied because nonoperative treatment had not been tried (71%) or had not been attempted for enough time (67%). Most (57%) prior authorization processes rarely/never changed the treatment provided. Most (56%) indicated that prior authorization rarely/never followed evidence-based guidelines. A majority (93%) expressed high administrative burden as well as negative clinical outcomes (87%) due to prior authorization including delays to access care (96%) at least sometimes.

DISCUSSION

Prior authorization has increased in the past 5 years resulting in high administrative burden. Prior authorizations were most common for TJA surgeries because certain nonoperative treatments were not attempted or not attempted for enough time. Surgeons indicated that prior authorization may be detrimental to high-value care and lead to potentially harmful delays in care without ultimately changing the management of the patient.

Trends in Revenue, Cost, and Contribution Margin for Total Joint Arthroplasty 2011-2021

BACKGROUND

Regulatory change has created a growing demand to decrease the hospital costs associated with primary total joint arthroplasty (TJA). Concurrently, the removal of lower extremity TJA from the in-patient only list has affected hospital reimbursement. The purpose of this study is to investigate trends in hospital revenue versus costs in primary TJA.

METHODS

We retrospectively reviewed all patients who underwent primary TJA from June 2011 to May 2021 at our institution. Patient demographics, revenue, total cost, direct cost, and contribution margin were collected. Changes over time as a percentage of 2011 numbers were analyzed. Linear regression analysis was used to determine overall trend significance and develop projection models.

RESULTS

Total knee arthroplasty (TKA) insured by government-managed/Medicaid (GMM) plans showed a significant upward trend (P = .013) in total costs. Direct costs of TKA across all insurance providers (P = .001 and P < .001) and total hip arthroplasty (THA) for Medicare (P = .009) and GMM (P = .001) plans demonstrated significant upward trends. Despite this, 2011-2021 modeling found no significant change in contribution margin for TKA and THA covered under all insurance plans. However, models based on 2018-2021 financial data demonstrated a significant downward trend in contribution margin across Medicare (P < .001) and GMM (P < .001) insurers for both TKA and THA.

CONCLUSION

Physician-led innovation in cost-saving strategies has maintained contribution margin over the past decade. However, the increase in direct costs seen over the past few years could lead to negative contribution margins over time, if further efficiency and cost-saving measures are not developed.

LEVEL III EVIDENCE

Retrospective Cohort Study.

Poor Patient Compliance Limits the Attainability of Patient-Reported Outcome Measure Completion Thresholds for the Comprehensive Care for Joint Arthroplasty Model

BACKGROUND

The Centers for Medicare and Medicaid Services (CMS) links patient-reported outcome measures (PROMs) with hospital reimbursement in some value-based models for total joint arthroplasty (TJA). This study evaluates PROM reporting compliance and resource utilization using protocol-driven electronic collection of outcomes for commercial and CMS alternative payment models (APMs).

METHODS

We analyzed a consecutive series of patients undergoing total hip arthroplasty (THA) and total knee arthroplasty (TKA) from 2016 and 2019. Compliance rates were obtained for reporting hip disability and osteoarthritis outcome score for joint replacement (HOOS-JR.), knee disability and osteoarthritis outcome score for joint replacement (KOOS-JR.), and 12-item short form survey (SF-12) surveys preoperatively and postoperatively at 6-months, 1 year, and 2- years. Of 43,252 THA and TKA patients, 25,315 (58%) were Medicare-only. Direct supply and staff labor costs for PROM collection were obtained. Chi-square testing compared compliance rates between Medicare-only and all-arthroplasty groups. Time-driven activity-based costing (TDABC) estimated resource utilization for PROM collection.

RESULTS

In the Medicare-only cohort, preoperative HOOS-JR./KOOS-JR. compliance was 66.6%. Postoperative HOOS-JR./KOOS-JR. compliance was 29.9%, 46.1%, and 27.8% at 6 months, 1 year, and 2 years, respectively. Preoperative SF-12 compliance was 70%. Postoperative SF-12 compliance was 35.9%, 49.6%, and 33.4% at 6 months, 1 year, and 2 years, respectively. Medicare patients had lower PROM compliance than the overall cohort (P < .05) at all time points except preoperative KOOS-JR., HOOS-JR., and SF-12 in TKA patients. The estimated annual cost for PROM collection was $273,682 and the total cost for the entire study period was $986,369.

CONCLUSION

Despite extensive experience with APMs and a total expenditure near $1,000,000, our center demonstrated low preoperative and postoperative PROM compliance rates. In order for practices to achieve satisfactory compliance, Comprehensive Care for Joint Replacement (CJR) compensation should be adjusted to reflect the costs associated with collecting these PROMs and CJR target compliance rates should be adjusted to reflect more attainable levels consistent with currently published literature.

Are Trends in Revision Total Joint Arthroplasty Sustainable? Declining Inflation-Adjusted Medicare Reimbursement for Hospitalizations

BACKGROUND

While the burden of revision total joint arthroplasty (TJA) procedures increases within the United States, it is unclear whether health care resource allocation for these complex cases has kept pace. This study examined the trends in hospital-level reimbursements for revision TJA hospitalizations.

METHODS

The Centers for Medicare and Medicaid Services (CMS) inpatient utilization and payment public use files from 2014 to 2019 were queried for diagnostic-related groups (DRGs) for revision TJA: DRG 467 (revision of hip or knee arthroplasty with complication or comorbidity [CC]) and DRG 468 (revision of hip or knee arthroplasty without CC or major CC). From 2014 to 2019, 170,808 revision TJA hospitalizations were billed to Medicare, and revision TJA procedures increased by 3,121 (10.7%). After adjusting to 2019 US dollars with the consumer price index, a multiple linear mixed-model regression analysis was performed. Analysis of covariance compared regressions from 2014 to 2019 for mean-adjusted Medicare payment and mean- adjusted charge were submitted for these DRGs.

RESULTS

Mean-adjusted average Medicare payment for DRG 467 decreased by $804.37 (-3.5%) from 2014 to 2019, whereas, that for DRG 468 decreased by $647.33 (-3.6%). The average inflation-adjusted Medicare payment for DRG 467 decreased at a greater rate during the study period, compared to that for DRG 468 (P = .02).

CONCLUSION

The decline in reimbursement for DRGs 467 and 468 reveals decreasing incentives for revision TJA hospitalizations. Further research should assess the efficacy of current Medicare payment algorithms and identify modifications which may provide for fair hospital level reimbursements.

Robotic-assisted TKA reduces surgery duration, length of stay and 90-day complication rate of complex TKA to the level of noncomplex TKA

INTRODUCTION

Complex primary total knee arthroplasties (TKA) are reported to be associated with excessive episode of care (EOC) costs as compared to noncomplex procedures. The impact of robotic assistance (rTKA) on economic outcome parameters in greater case complexity has not been described yet. The purpose of this study was to investigate economic outcome parameters in the 90-days postoperative EOC in robotic-assisted complex versus noncomplex procedures.

MATERIALS AND METHODS

This study is a retrospective, single-center review of 341 primary rTKAs performed between 2017 and 2020. Patient collective was stratified into complex (n = 218) and noncomplex TKA (n = 123) based on the presence of the following criteria: Obese BMI, coronal malalignment, flexion contracture > 10°, posttraumatic status, previous correction osteotomy, presence of hardware requiring removal during surgery, severe rheumatoid arthritis. Group comparison included surgery duration, length of stay (LOS), surgical site complications, readmissions, and revision procedures in the 90-days EOC following rTKA.

RESULTS

The mean surgery duration was marginally longer in complex rTKA, but showed no significant difference (75.26 vs. 72.24 min, p = 0.258), neither did the mean LOS, which was 8 days in both groups (p = 0.605). No differences between complex and noncomplex procedures were observed regarding 90-days complication rates (7.34 vs. 4.07%, p = 0.227), readmission rates (3.67 vs. 3.25%, p = 0.841), and revision rates (2.29 vs. 0.81%, p = 0.318).

CONCLUSIONS

Robotic-assisted primary TKA reduces the surgical time, inpatient length of stay as well as 90-days complication and readmission rates of complex TKA to the level of noncomplex TKA. Greater case complexity does not seem to have a negative impact on economic outcome parameters when surgery is performed with robotic assistance.

Achilles Tendon Repairs: Identification of Risk Factors for and Economic Impact of Complications and Reoperation

BACKGROUND

Compared with nonoperative management, Achilles tendon repair is associated with increased rates of complications and increased initial healthcare cost. However, data are currently lacking on the risk factors for these complications and the added healthcare cost associated with common preoperative comorbidities.

HYPOTHESIS

Identify the independent risk factors for complications and reoperation after acute Achilles tendon repair and calculate the added cost of care associated with having each preoperative risk factor.

STUDY DESIGN

Retrospective cohort study.

LEVEL OF EVIDENCE

Level 3.

METHODS

A retrospective review of a large commercial claims database was performed to identify patients who underwent primary operative management for Achilles tendon rupture between 2007 and 2016. The primary outcome measures of the study were risk factors for (1) postoperative complications, (2) revision surgery, and (3) increased healthcare resource utilization.

RESULTS

A total of 50,279 patients were included. The overall complication rate was 2.7%. The most common 30-day complication was venous thromboembolism (1.2%). The rate of revision surgery was 2.5% at 30 days and 4.3% at 2 years. Independent risk factors for 30-day complications in our cohort included increasing age, hyperlipidemia, hypertension, female sex, obesity, and diabetes. Independent risk factors for revision surgery within 2 years included female sex, tobacco use, hypertension, obesity, and the presence of any postoperative complication. The average 5-year cost of operative intervention was $17,307. The need for revision surgery had the largest effect on 5-year overall cost, increasing it by $6776.40. This was followed by the presence of a postoperative complication ($3780), female sex ($3207.70), and diabetes ($3105).

CONCLUSION

Achilles tendon repair is a relatively low-risk operation. Factors associated with postoperative complications include increasing age, hyperlipidemia, hypertension, female sex, obesity, and diabetes. Factors associated with the need for revision surgery include female sex, hypertension, obesity, and the presence of any postoperative complication. Female sex, diabetes, the presence of any complication, and the need for revision surgery had the largest added costs associated with them.

CLINICAL RELEVANCE

Surgeons can use this information for preoperative decision-making and during the informed consent process.

The Impact of Race and Socioeconomic Status on Total Joint Arthroplasty Care

BACKGROUND

Racial minorities and patients from lower socioeconomic backgrounds are less likely to undergo total joint arthroplasty (TJA) for degenerative joint disease (DJD). However, when these patients do present for care, little is known about the overall severity of DJD and surgical wait times.

METHODS

A retrospective cohort of 407 patients (131 black and 276 white) who presented to an arthroplasty clinic and went on to receive TJA was established. Severity of osteoarthritis was assessed radiographically via Kellgren-Lawrence (KL) grade. Preoperative Knee Society Score (KSS) and Harris Hip Score (HHS) were used to measure joint pain and function. Multivariate regression modeling and analysis of covariance were used to examine racial and socioeconomic differences in KL grade, KSS, HHS, and time to surgery.

RESULTS

Black patients presented with significantly greater KL scores than white patients (P = .046, odds ratio = 1.65, 95% confidence interval [1.01, 2.70]). In contrast, there were no statistically significant racial differences in the mean preoperative KSS (P = .61) or HHS (P = .69). Black patients were also found to wait, on average, 35% longer for TJA (P = .03, hazard ratio = 1.35, 95% confidence interval [1.04, 1.75]). Low income was associated with higher KL grade (P = .002), lower KSS (P = .07), and lower HHS (P = .001).

CONCLUSION

Despite presenting with more advanced osteoarthritis, black patients reported similar levels of joint dysfunction and had longer surgical wait times when compared with white patients. Lower socioeconomic status was similarly associated with more severe DJD.

Which Socioeconomic Factors Affect Outcomes Following Total Hip and Knee Arthroplasty?

BACKGROUND

Studies have shown that lower socioeconomic status may result in adverse outcomes following total hip (THA) and total knee arthroplasty (TKA). The optimal method of defining socioeconomic status, however, continues to be debated. The purpose of this study is to determine which socioeconomic variables are associated with poor outcomes following THA and TKA.

METHODS

We reviewed a consecutive series of 2770 primary THA and TKA patients from 2015 to 2018. Utilizing census data based upon the patient's ZIP code, we extracted poverty, unemployment, high school graduation, and vehicle possession rates. We collected demographics, comorbidities, discharge disposition, 90-day readmissions, and postoperative functional outcome scores for each patient. We then performed a multivariate regression analysis to identify the effect of each socioeconomic variable on postoperative outcomes.

RESULTS

Patients from areas with high unemployment (P = .008) and low high school graduation rates (P = .019) had a higher age-adjusted Charlson Comorbidity Index. High poverty levels, high unemployment, lower high school graduation rate, and lower vehicle possession rates did not have a significant effect on functional outcomes (all P > .05). In the multivariate analysis, no socioeconomic variable demonstrated an increased rate of rehabilitation discharge, revision, or readmission (all P > .05).

CONCLUSION

Patients undergoing THA and TKA from areas with high unemployment and lower educational levels do have more medical comorbidities. However, none of the 4 socioeconomic variables studied are independently associated with higher rates of readmission, discharge to rehabilitation, or worse functional outcomes. Patients from disadvantaged areas should not be denied access to arthroplasty care based on socioeconomic status alone.

Higher Patient Complexities are Associated with Increased Length of Stay, Complications, and Readmissions After Total Hip Arthroplasty

INTRODUCTION

There is an increased incidence of complex patients undergoing total hip arthroplasty (THA), which demands a rigorous preoperative, intraoperative, and postoperative assessment. It is important how increases in patient complexity impact a variety of patient outcomes. Therefore, the purpose of our study is to determine if a higher Elixhauser Comorbidity Index (ECI), a measure of patient complexity, is correlated with: 1) longer hospital length of stay; 2) increased 90-day medical complications; 3) higher 90-day readmissions; and 4) greater two-year implant-related complications following primary THA.

MATERIALS AND METHODS

Patients undergoing primary THA from January 1, 2004 to December 31, 2015 were queried from the Medicare Standard Analytical Files using the International Classification of Disease, ninth revision (ICD-9) procedure code 81.51. The queried patients (387,831) were filtered by ECI scores of 1 to 5. Patients who have ECI scores of 2 to 5 represented the study cohorts and were matched according to age and sex to patients who have the lowest ECI score (ECI of 1). All cohorts were longitudinally followed to assess and compare hospital length of stay, 90-day medical complications, 90-day readmissions, and two-year implant-related complications. We compared odds-ratios (OR), 95% confidence intervals (95% CI), and p-values using logistic regression analyses and Welch's t-tests.

RESULTS

Patients who have ECI scores greater than 1 had higher hospital length of stay (p<0.001), 90-day medical complications (p<0.001), 90-day readmissions (p<0.001), and two-year implant-related complications (p<0.001). Patients who have an ECI score of 2 (1.26, 95% CI: 1.20-1.32), ECI of 3 (1.61, 95% CI: 1.53-1.69), ECI of 4 (2.05, 95% CI: 1.95-2.14), and ECI of 5 (2.32, 95% CI: 2.21-2.43) had an increasing trend for readmissions, with higher ECI scores correlating with greater odds of readmission following primary THA. Two-year implant-related complications also showed a similar increasing trend with greater patient complexity. Patients who had an ECI score of 5 (2.54, 95% CI: 2.39-2.69) had more implant-related complications compared to patients who had an ECI score of 2 (1.39, 95% CI:1.31-1.48).

CONCLUSION

The results of this study illustrate that a higher Elixhauser-Comorbidity Index is an independent risk factor for longer hospital length of stay, higher 90-day medical complications, greater 90-day readmissions, and increased two-year implant-related complications following primary THA. This study is important as it further defines and heightens awareness of adverse events for complex patients undergoing this procedure. Future studies can examine if these events can potentially be mitigated through reductions in ECI scores prior to surgery and increased incentives for the healthcare team.

The Effect of Medicare's Bundled Payments for Care Initiative on Patient Risk Factors Prior to Total Knee Arthroplasty

BACKGROUND

Medicare's Bundled Payments for Care Initiative (BPCI) is a risk-sharing alternative payment model. There is a concern that BPCI providers may avoid operating on obese patients and active smokers to reduce costs. We sought to understand if increased focus on these patient factors has led to a change in patient demographics in Medicare-insured patients undergoing total knee arthroplasty (TKA).

METHODS

We retrospectively reviewed all patients who underwent TKA at an academic orthopedic specialty hospital between 1/1/13 and 8/31/19. Surgical date, insurance provider, BMI, and smoking status were collected. Patients were categorized as a current, former, or never smoker. Patients were categorized as obese if their BMI was >30 kg/m², morbidly obese if their BMI was >40 kg/m², and super obese if their BMI was >50 kg/m².

RESULTS

In total, 10,979 patients with complete insurance information were analyzed. There was no statistically significant change in the proportion of Medicare patients who were active smokers (4.34% in 2013, 4.85% in 2019, Pearson correlation coefficient = 0.6092, P = .146). The proportion of Medicare patients with BMI >30 kg/m² increased over the study period (35.84% in 2013, 55.77% in 2019, Pearson correlation coefficient = 0.8505, P = .015). When looking at patients with BMI >40 kg/m² and >50 kg/m², there was no significant change.

CONCLUSIONS

Despite concern that reimbursement payments could alter access to care for patients with certain risk factors, this study did not find a noticeable difference in the representation of patients with obesity and smoking status undergoing TKA following the installation of BPCI.

LEVEL OF EVIDENCE

III, retrospective observational analysis.

Risk Adjustment for Episode-of-Care Costs After Total Joint Arthroplasty: What is the Additional Cost of Individual Comorbidities and Demographics?

INTRODUCTION

Concerns exist regarding the lack of risk adjustment in alternative payment models for patients who may use more resources in an episode of care. The purpose of this study was to quantify the additional costs associated with individual medical comorbidities and demographic variables.

METHODS

We reviewed a consecutive series of primary total hip and knee arthroplasty patients at our institution from 2015 to 2016 using claims data from Medicare and a single private insurer. We collected demographic data and medical comorbidities for all patients. To control for confounding variables, we performed a stepwise multivariate regression to determine the independent effect of medical comorbidities and demographics on 90-day episode-of-care costs.

RESULTS

Six thousand five hundred thirty-seven consecutive patients were identified (4,835 Medicare and 1,702 private payer patients). The mean 90-day episode-of-care cost for Medicare and private payers was $19,555 and $30,020, respectively. Among Medicare patients, comorbidities that significantly increased episode-of-care costs included heart failure ($3,937, P < 0.001), stroke ($2,604, P = 0.002), renal disease ($2,479, P = 0.004), and diabetes ($1,368, P = 0.002). Demographics that significantly increased costs included age ($221 per year, P < 0.001), body mass index (BMI; $106 per point, P < 0.001), and unmarried marital status ($1896, P < 0.001). Among private payer patients, cardiac disease ($4,765, P = 0.001), BMI ($149 per point, P = 0.004) and age ($119 per year, P = 0.002) were associated with increased costs.

DISCUSSION

Providers participating in alternative payment models should be aware of factors (cardiac history, age, and elevated BMI) associated with increased costs. Further study is needed to determine whether risk adjustment in alternative payment models can prevent problems with access to care for these high-risk patients.

Subclinical Hypothyroidism Affects Postoperative Outcome of Patients Undergoing Total Knee Arthroplasty

OBJECTIVE

The aim of this study was to investigate whether subclinical hypothyroidism could increase the risk of postoperative complications in patients undergoing primary total knee arthroplasty (TKA).

METHODS

A prospective case-control study of 796 patients undergoing primary TKA between January 2015 and January 2020 was performed. A total of 700 patients (87.9%) were female and the average age of included patients was 65.0 years, with a standard deviation of 5.6. The participants who had subclinical hypothyroidism were referred to as the case group, while those without abnormal thyrotropin (TSH) were included in the control group (matched for age and gender). The fasting plasma levels of TSH were tested in the morning in all patients. The diagnosis of subclinical hypothyroidism was completed by a senior endocrinologist based on laboratory tests; namely, a serum TSH ≥ 5 mu/L and normal free thyroxine (FT4). Subclinical hypothyroidism was further described as mild (TSH < 10 mu/L) or severe (TSH ≥ 10 mu/L). The incidence of 90-day postoperative complications was compared between two cohorts. Logistic regression analysis was used for the risk factors of 90-day postoperative complications following TKA.

RESULTS

A total of 398 patients had a diagnosis of subclinical hypothyroidism. Among them, 275 cases (69.1%) were described as mild (79 patients [19.8%] with low FT4 and 196 patients [49.2%] with normal FT4 in the repeated test) and 123 cases (30.9%) as severe subclinical hypothyroidism. Of the 196 patients (49.2%) with mild subclinical hypothyroidism and normal FT4, 63 patients (15.8%) had symptoms before surgery. Patients were followed up for an average duration of 25.4 months (6 to 43 months). A total of 265 patients (66.6%) received preoperative treatment for subclinical hypothyroidism, with an average therapy time of 9.2 months. There were 162 patients (40.7%) with positive autoantibodies to thyroid peroxidase (anti-TPO). There were no statistically significant differences in baseline data between cohorts (all P > 0.05). As for the cumulative 90-day outcomes, subclinical hypothyroidism increased the incidences of both medical and surgical complications following primary TKA compared to those without this condition (11.6% vs 7.2%, OR = 1.55, 95% confidence interval [CI] = 1.47-1.62, P < 0.05). Subclinical hypothyroidism caused patients to suffer increased total incidence of readmission within the first 90 days after discharge when compared to those without this condition (20.61% vs 14.15%, OR = 1.45, 95% CI = 1.41-1.49, P < 0.001). Controlling for preoperative and intraoperative variables, the patients with TSH ≥ 10 mu/L and positive anti-TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation were more likely to experience postoperative complications within 90 days of TKA.

CONCLUSION

Subclinical hypothyroidism might increase the risk of postoperative complications within 90 days of TKA, especially for the patients with TSH ≥ 10 mu/L and positive anti-TPO and those without corrected subclinical hypothyroid and thyroid hormone supplementation.

Free Falling: Declining Inflation-Adjusted Payment for Arthroplasty Surgeons

BACKGROUND

Over the past decade, there have been ongoing concerns over declining surgeon compensation for lower extremity arthroplasty. We aimed to determine changes in surgeon payment, patient charges, and overall reimbursement rates for patients undergoing unicompartmental arthroplasty (UKA) and both primary and revision total knee (TKA) and hip (THA) arthroplasty.

METHODS

Using Medicare data from 2012 to 2017, we determined inflation-adjusted changes in annual surgeon payment (professional fee), patient charges, and reimbursement rate (payment-to-charge ratio) for UKA and primary/revision TKA and THA. Both nonweighted and weighted (by procedure frequency/volume) means were calculated.

RESULTS

Inflation-adjusted surgeon payment decreased for all procedures analyzed, with primary TKA (-17%) and THA (-11%) falling the most. Payment for UKA increased the most (+30%). There was a small increase in charges for THA revision (+2.2%, +2.1%, and +3.2% for acetabulum only, femur only, and both components, respectively). Charges for primary TKA (-3.7%) and THA (-1.5%) decreased slightly. The reimbursement rate for all procedures fell with UKA (-15%), TKA (-14%), and THA (-10%) falling the most. After weighting by procedure frequency/volume and combining all surgeries, average charges fell slightly (-0.7%), whereas surgeon payment (-13%) and reimbursement rate (-12%) fell more sharply.

CONCLUSION

Although patient charges have grown in pace with the inflationary rate for primary and revision TKA and THA, surgeon payment and reimbursement rates have fallen sharply. The orthopedic community needs to be aware of these financial trends to communicate to payers and health care policy makers the importance of protecting a sustainable payment infrastructure.

Cost Analysis of Medicare Patients with Varying Complexities Who Underwent Total Knee Arthroplasty

The effort to reduce overall healthcare costs may affect more complex patients, as their pre- and postoperative care can be substantially involved. Therefore, the purpose of this study was to use a large nationwide insurance database to compare (1) costs, (2) reimbursements, and (3) net losses of 90-day episodes of care (EOC) for total knee arthroplasty (TKA) patients according to Elixhauser's Comorbidity Index (ECI) scores. All TKAs performed between 2005 and 2014 in the Medicare Standard Analytic Files were extracted from the database and stratified based on ECI scores, ranging from 1 to 5. ECI 1 patients served as the control cohort, while ECI 2, 3, 4, and 5 patients were considered study cohorts. Each study cohort and control cohort were matched based on age and sex, resulting in a total of 715,398 patients included for analysis. Total EOC costs, reimbursements, and total net losses (defined as total EOC costs minus total EOC reimbursements) were compared between the cohorts. Overall, total EOC costs increased with ECI. For example, compared with the matched ECI 1 cohorts, the total EOC costs for ECI 5 patients ($56,589.19 vs. $51,747.54) were significantly greater (p < 0.01). Although reimbursements increased with increasing ECI, so did net losses. The net losses for ECI 5 patients were greater than that for ECI 1 patients ($42,309.39 vs. $40,007.82). The bundled payments for care improvement (BPCI) and comprehensive care for joint replacement (CJR) are alternative payment models that might de-incentivize treatment of more complex patients. Our study found that despite increasing reimbursements, overall costs, and therefore net losses, were greater for more complex patients with higher ECI scores.

The Cost of Poor Mental Health in Total Joint Arthroplasty

BACKGROUND

The purpose of this analysis was to evaluate (1) the impact of depression on resource utilization and financial outcomes in bundled total joint arthroplasty (TJA) and (2) whether similar effects are seen using baseline patient-reported outcome scores.

METHODS

All elective bundled TJA cases from 2017 to 2018 at an academic system in the New York City area were included. We analyzed variables associated with cost differences seen between patients with and without depression, and between patients with low (<40th percentile) and high baseline (>60th percentile) Veterans RAND 12-Item Health Survey mental component scores (MCSs). We also analyzed whether depression or low MCS could predict worse financial outcomes.

RESULTS

Our population included 825 patients, 418 with patient-reported outcome scores data. Depression was associated with higher rates of skilled nursing facility (SNF) discharge (42.7% vs 36.5%, P = .04), SNF payments ($16,200 vs $12,100, P = .0002), and average total episode costs ($31,000 vs $27,000, P = .04). Depression predicted bundle cost to be greater than target price (OR 1.82, 95% CI: 1.04-.16; P = .04) and SNF payment greater than 75th percentile (OR: 1.91; 95% CI: 1.00-3.65; P < .05). Similar effects were not seen using MCS.

CONCLUSION

This is the first study to determine that depression predicts bundle cost greater than target price and SNF payment greater than 75th percentile. Our results emphasize the importance of accurate preoperative assessment of mental health in optimization of care, focusing on attenuating the increased SNF payments associated with depression. As similar effects were not seen using MCS, future studies should analyze the use of validated screening tools for depression, such as the PHQ-9, for more accurate assessments of patient mental health in TJA.

Total Knee Arthroplasty Outcomes in Patients with Medicare, Medicare Advantage, and Commercial Insurance

As more commercial insurance companies adopt a bundled reimbursement model, similar to the Comprehensive Care for Joint Replacement (CJR) algorithm for Medicare beneficiaries, accurate risk adjustment of patient-reported outcomes (PROs) is critical to ensure success. With this movement toward bundled reimbursement, it is unknown if a formula adjusting for similar risks in the Medicare population could be applied to PROs in commercially insured and Medicare Advantage populations undergoing total knee arthroplasty (TKA). This study was performed to compare PROs after TKA in these insurance groups after adjusting for proposed risks. Demographics and clinical data were abstracted from medical records of 302 patients who underwent TKA performed by a single surgeon at a university-based orthopaedic practice during 2013 to 2017. Differences in PROs between commercially insured, Medicare Advantage, and Medicare patients during the 6 months following surgery were evaluated while controlling for demographics, clinical data, and baseline PRO scores. Medicare and Medicare Advantage patients were older (p < 0.001) and had more comorbidities (p = 0.001) than commercial patients. During the first 3 months following TKA, patients in all three groups experienced similar rates of recovery. At 6 months after surgery, outcomes began to diverge by insurance group. Medicare patients reported significantly less ability to perform activities of daily living (78.6 vs. 63.2; p = 0.001), worse physical function (39.6 vs. 44.9; p = 0.003), and more pain interference (57.9 vs. 52.4; p = 0.018) at day 180 than commercially insured patients. There were no statistically significant differences between Medicare Advantage patients and either commercially insured or Medicare patients. Therefore, commercial insurance companies that intend to apply a risk-adjusted equation similar to the CJR algorithm to commercial populations should be cautioned since the postoperative outcomes in this investigation differed after adjusting for the same risk factors that have been proposed for inclusion in the CJR algorithm. Nonetheless, further studies should be performed to ensure that companies participating in bundled reimbursement models have a positive influence on comprehensive health care for patients and providers. This is a level III, retrospective prognostic study.

Conversion Total Knee Arthroplasty is Associated with Increased Post-Acute Care Costs

BACKGROUND

Alternative payment models have been viewed as successfully decreasing costs following primary total knee arthroplasty (TKA) while maintaining quality. Concerns exist regarding access to care for patients who may utilize more resources in a bundled payment arrangement. The purpose of this study is to determine if patients undergoing conversion of prior surgery to TKA have increased costs compared to primary TKA patients.

METHODS

Claims from Medicare and a single private insurer were queried for all primary TKA patients at our institution from 2015 to 2016. Ninety-day post-acute care costs were compared between primary and conversion TKA. Secondary endpoints included discharge disposition, complications, and readmissions. A multivariate regression analysis was performed to identify independent risk factors for increased post-acute care costs and short-term outcome metrics.

RESULTS

Of 3999 primary TKA procedures, 948 patients (23%) underwent conversion TKA. Conversion TKA was associated with greater post-acute care costs in patients with commercial insurance ($4714 vs $3759, P = .034). Among Medicare beneficiaries, prior ligament reconstruction was associated with increased post-acute care costs ($1917 increase, P = .036), while prior fracture fixation approached statistical significance ($2402 increase, P = .055). Conversion TKA was an independent risk factor for readmissions (odds ratio 1.46, 95% confidence interval 1.00-2.17, P = .050), while patients with a prior open knee procedure had higher rates of complications (odds ratio 2.41, 95% confidence interval 1.004-5.778, P = .049).

CONCLUSION

Our data suggest that conversion from prior knee surgery to TKA is associated with increased 90-day post-acute care costs and resource utilization, particularly prior open procedures. Without appropriate risk adjustment in alternative payment models, surgeons may be financially deterred from providing quality arthroplasty care given the reduced net payment and surgical complexity of such cases.

Anesthesia and Analgesia Practices in Total Joint Arthroplasty: A Survey of the American Association of Hip and Knee Surgeons Membership

BACKGROUND

The purpose of this study is to survey the current analgesia and anesthesia practices used by total joint arthroplasty surgeon members of the American Association of Hip and Knee Surgeons (AAHKS).

METHODS

A survey of 28 questions was created and approved by the AAHKS Research Committee. The survey was distributed to all 2208 board-certified adult reconstruction surgeon members of AAHKS in November 2018.

RESULTS

There were 622 responses (28.2%) to the survey. A majority of respondents (93.2%, n = 576) use preemptive analgesia prior to total joint arthroplasty. Most respondents use a spinal for total knee arthroplasty (TKA) (74.4%) and total hip arthroplasty (THA) (72.6%). A peripheral nerve block is routinely used by 68.7% of respondents in primary TKA. Periarticular injection or local infiltration anesthesia is routinely used by 80.3% of respondents for both TKA and THA patients. The average number of opioid pills prescribed postoperatively after TKA is 49 pills (range 0-200) and after THA is 44 pills (range 0-200). Most surgeons (58%) expect that this prescription should last for 2 weeks. A majority of respondents (74.0%) use multimodal analgesics in addition to opioids.

CONCLUSION

There is no consensus regarding the optimal multimodal anesthetic and analgesic regimen for total joint arthroplasty among surveyed board-certified arthroplasty surgeon members of AAHKS. Understanding current practice patterns in anesthesia, analgesia, and opioid prescribing may serve as a platform for future work aimed at establishing best clinical practices of maximizing effective postoperative pain control and minimizing the risks associated with prescribing opioids.

Conversion Total Knee Arthroplasty Needs Its Own Diagnosis-Related Group Code

BACKGROUND

Conversion from a prior knee procedure has been demonstrated to require greater operative times and resources, but still lacks a separate procedural or facility code from primary total knee arthroplasty (TKA). The purpose of this study is to determine differences in facility costs between patients who underwent primary TKA and those who underwent conversion TKA.

METHODS

We retrospectively reviewed a consecutive series of patients undergoing primary TKA at 2 hospitals from 2015 to 2017, comparing itemized facility costs between primary and conversion TKA patients. A multivariate regression analysis was performed to identify independent risk factors for increased facility costs, the need for additional implants, length of stay, and discharge disposition.

RESULTS

Of 2447 TKA procedures, 678 (27.7%) underwent conversion TKA, which was associated with greater implant costs ($3931.47 vs $2864.67, P = .0120) and total facility costs in a multivariate regression ($94.30 increase, P = .0316). When controlling for confounding variables, patients with a prior ligament reconstruction ($402 increase, P = .0002) and prior open reduction and internal fixation ($847 increase, P = .0020) had higher costs and were more likely to require stemmed implants (P < .05). There was an increase in TKA implant cost by $538 in patients with implants from a prior procedure (P < .0001).

CONCLUSION

Conversion TKA is associated with greater implant and inpatient facility costs than primary TKA, particularly those who had a history of an open knee procedure. A separate diagnosis-related group should be created for conversion TKA given the increased cost and complexity of these procedures compared to primary TKA.

Bundled Care for Hip Fractures: A Machine-Learning Approach to an Untenable Patient-Specific Payment Model

OBJECTIVES

With the transition to a value-based model of care delivery, bundled payment models have been implemented with demonstrated success in elective lower extremity joint arthroplasty. Yet, hip fracture outcomes are dependent on patient-level factors that may not be optimized preoperatively due to acuity of care. The objectives of this study are to (1) develop a supervised naive Bayes machine-learning algorithm using preoperative patient data to predict length of stay and cost after hip fracture and (2) propose a patient-specific payment model to project reimbursements based on patient comorbidities.

METHODS

Using the New York Statewide Planning and Research Cooperative System database, we studied 98,562 Medicare patients who underwent operative management for hip fracture from 2009 to 2016. A naive Bayes machine-learning model was built using age, sex, ethnicity, race, type of admission, risk of mortality, and severity of illness as predictive inputs.

RESULTS

Accuracy was demonstrated at 76.5% and 79.0% for length of stay and cost, respectively. Performance was 88% for length of stay and 89% for cost. Model error analysis showed increasing model error with increasing risk of mortality, which thus increased the risk-adjusted payment for each risk of mortality.

CONCLUSIONS

Our naive Bayes machine-learning algorithm provided excellent accuracy and responsiveness in the prediction of length of stay and cost of an episode of care for hip fracture using preoperative variables. This model demonstrates that the cost of delivery of hip fracture care is dependent on largely nonmodifiable patient-specific factors, likely making bundled care an implausible payment model for hip fractures.

Preoperative Patient-Reported Outcomes and Clinical Characteristics as Predictors of 90-Day Cost/Utilization and Complications

BACKGROUND

With the advent of mandatory bundle payments for total joint arthroplasty (TJA), assessing patients' risk for increased 90-day complications and resource utilization is crucial. This study assesses the degree to which preoperative patient-reported outcomes predict 90-day complications, episode costs, and utilization in TJA patients.

METHODS

All TJA cases in 2017 at 2 high-volume hospitals were queried. Preoperative HOOS/KOOS JR (Hip Injury and Osteoarthritis Outcome Score/Knee Injury and Osteoarthritis Outcome Score) and Veterans RAND 12-item health survey (VR-12) were administered to patients preoperatively via e-collection platform. For patients enrolled in the Medicare bundle, cost data were extracted from claims. Bivariate and multivariate regression analyses were performed.

RESULTS

In total, 2108 patients underwent TJA in 2017; 1182 (56%) were missing patient-reported outcome data and were excluded. The final study population included 926 patients, 199 (21%) of which had available cost data. Patients with high bundle costs tended to be older, suffer from vascular disease and anemia, and have higher Charlson scores (P < .05 for all). These patients also had lower baseline VR-12 Physical Component Summary Score (PCS; 24 vs 30, P ≤ .001) and higher rates of extended length of stay, skilled nursing facility discharge, 90-day complications, and 90-day readmission (P ≤ .04 for all). In multivariate analysis, higher baseline VR-12 PCS was protective against extended length of stay, skilled nursing facility discharge, >75th percentile bundle cost, and 90-day bundle cost exceeding target bundle price (P < .01 for all). Baseline VR-12 Mental Component Summary Score and HOOS/KOOS JR were not predictive of complications or bundle cost.

CONCLUSION

Low baseline VR-12 PCS is predictive of high 90-day bundle costs. Baseline HOOS/KOOS JR scores were not predictive of utilization or cost. Neither VR-12 nor HOOS/KOOS JR was predictive of 90-day readmission or complications.

Development and Validation of a Machine Learning Algorithm After Primary Total Hip Arthroplasty: Applications to Length of Stay and Payment Models

BACKGROUND

Value-based payment programs in orthopedics, specifically primary total hip arthroplasty (THA), present opportunities to apply forecasting machine learning techniques to adjust payment models to a specific patient or population. The objective of this study is to (1) develop and validate a machine learning algorithm using preoperative big data to predict length of stay (LOS) and patient-specific inpatient payments after primary THA and (2) propose a risk-adjusted patient-specific payment model (PSPM) that considers patient comorbidity.

METHODS

Using an administrative database, we applied 122,334 patients undergoing primary THA for osteoarthritis between 2012 and 16 to a naïve Bayesian model trained to forecast LOS and payments. Performance was determined using area under the receiver operating characteristic curve and percent accuracy. Inpatient payments were grouped as <$12,000, $12,000-$24,000, and >$24,000. LOS was grouped as 1-2, 3-5, and 6+ days. Payment model uncertainty was applied to a proposed risk-based PSPM.

RESULTS

The machine learning algorithm required age, race, gender, and comorbidity scores ("risk of illness" and "risk of morbidity") to demonstrate excellent validity, reliability, and responsiveness with an area under the receiver operating characteristic curve of 0.87 and 0.71 for LOS and payment. As patient complexity increased, error for predicting payment increased in tiers of 3%, 12%, and 32% for moderate, major, and extreme comorbidities, respectively.

CONCLUSION

Our preliminary machine learning algorithm demonstrated excellent construct validity, reliability, and responsiveness predicting LOS and payment prior to primary THA. This has the potential to allow for a risk-based PSPM prior to elective THA that offers tiered reimbursement commensurate with case complexity.

LEVEL OF EVIDENCE

III.

Risk Adjustment Is Necessary in Value-Based Payment Models for Arthroplasty for Oncology Patients

BACKGROUND

Value-based payment models such as bundled payments have been introduced to reduce costs following total hip arthroplasty (THA). Concerns exist, however, about access to care for patients who utilize more resources. The purpose of this study is thus to compare resource utilization and outcomes of patients undergoing THA for malignancy with those undergoing THA for fracture or osteoarthritis.

METHODS

We queried the American College of Surgeons National Surgical Quality Improvement Program database to identify all hip arthroplasties performed from 2013 to 2016 for a primary diagnosis of malignancy (n = 296), osteoarthritis (n = 96,480), and fracture (n = 13,406). The rates of readmissions, reoperations, comorbidities, mortality, and surgical characteristics were compared between the 3 cohorts. To control for confounding variables, a multivariate analysis was performed to identify independent risk factors for resource utilization and outcomes following THA.

RESULTS

Patients undergoing THA for malignancy had a longer mean operative time (155.7 vs 82.9 vs 91.0 minutes, P < .001), longer length of stay (9.0 vs 7.2 vs 2.6 days, P < .001), and were more likely to be discharged to a rehabilitation facility (42.1% vs 61.8% vs 20.2%, P < .001) than patients with fracture or osteoarthritis. When controlling for demographics and comorbidities, patients undergoing THA for malignancy had a higher rate of readmission (adjusted odds ratio 3.39, P < .001) and reoperation (adjusted odds ratio 3.71, P < .001).

CONCLUSION

Patients undergoing THA for malignancy utilize more resources in an episode-of-care and have worse outcomes. Risk adjustment is necessary for oncology patients in order to prevent access to care problems for these high-risk patients.

Predicting Inpatient Status After Total Hip Arthroplasty in Medicare-Aged Patients

BACKGROUND

The Centers for Medicare and Medicaid Services has solicited comments regarding the removal of total hip arthroplasty (THA) from its inpatient-only list. The goal of this study is to develop and internally validate a risk stratification nomogram to aid in the identification of optimal inpatient candidates in this patient population.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program database was utilized to identify all patients >65 years of age who underwent primary THA between 2006 and 2015. Inpatient stay was the primary outcome measure, as defined by stay >2 days in length. The impact of numerous demographic, comorbid, and perioperative variables was assessed through a multivariable logistic regression analysis to construct a predictive nomogram.

RESULTS

In total, 30,587 inpatient THAs and 17,024 outpatient THAs were analyzed. Heart failure (odds ratio [OR] 2.11, P = .001), simultaneous bilateral THA (OR 2.47, P < .0001), age >80 years (OR 2.91, P < .0001), female gender (OR 1.90, P < .0001), and dependent functional status (OR 1.89, P < .0001) were the most influential determinants of inpatient status. The final prediction algorithm showed good accuracy, excellent calibration, and internal validation (bias-corrected concordance index of 0.69).

CONCLUSION

Our model enabled accurate and simple identification of the best candidates for inpatient admission after THA in Medicare-aged patients. Given the increasing feasibility of outpatient THA coupled with the likelihood of THA being removed from the Centers for Medicare and Medicaid Services inpatient-only list, this model provides a framework to guide discussion and decision-making for stakeholders.

2018 John Charnley Award: Analysis of US Hip Replacement Bundled Payments: Physician-initiated Episodes Outperform Hospital-initiated Episodes

BACKGROUND

The Centers for Medicare & Medicaid Services (CMS) launched the Bundled Payment for Care Improvement (BPCI) initiative in 2013 to create incentives to improve outcomes and reduce costs in various clinical settings, including total hip arthroplasty (THA). This study seeks to quantify BPCI initiative outcomes for THA and to determine the optimal party (for example, hospital versus physician group practice [PGP]) to manage the program.

QUESTIONS/PURPOSES

(1) Is BPCI associated with lower 90-day payments, readmissions, or mortality for elective THA? (2) Is there a difference in 90-day payments, readmissions, or mortality between episodes initiated by PGPs and episodes initiated by hospitals for elective THA? (3) Is BPCI associated with reduced total Elixhauser comorbidity index or age for elective THA?

METHODS

We performed a retrospective analysis on the CMS Limited Data Set on all Medicare primary elective THAs without a major comorbidity performed in the United States (except Maryland) between January 2013 and March 2016, totaling more than USD 7.1 billion in expenditures. Episodes were grouped into hospital-run BPCI (n = 42,922), PGP-run BPCI (n = 44,662), and THA performed outside of BPCI (n = 284,002). All Medicare Part A payments were calculated over a 90-day period after surgery and adjusted for inflation and regional variation. For each episode, age, sex, race, geographic location, background trend, and Elixhauser comorbidities were determined to control for major confounding variables. Total payments, readmissions, and mortality were compared among the groups with logistic regression.

RESULTS

When controlling for demographics, background trend, geographic variation, and total Elixhauser comorbidities in elective Diagnosis-Related Group 470 THA episodes, BPCI was associated with a 4.44% (95% confidence interval [CI], -4.58% to -4.30%; p < 0.001) payment decrease for all participants (USD 1244 decrease from a baseline of USD 18,802); additionally, odds ratios (ORs) for 90-day mortality and readmissions were unchanged. PGP groups showed a 4.81% decrease in payments (95% CI, -5.01% to -4.61%; p < 0.001) after enrolling in BPCI (USD 1335 decrease from a baseline of USD 17,841). Hospital groups showed a 4.04% decrease in payments (95% CI, -4.24% to 3.84%; p < 0.01) after enrolling in BPCI (USD 1138 decrease from a baseline of USD 19,799). The decrease in payments of PGP-run episodes was greater compared with hospital-run episodes. ORs for 90-day mortality and readmission remained unchanged after BPCI for PGP- and hospital-run BPCI programs. Patient age and mean Elixhauser comorbidity index did not change after BPCI for PGP-run, hospital-run, or overall BPCI episodes.

CONCLUSIONS

Even when controlling for decreasing costs in traditional fee-for-service care, BPCI is associated with payment reduction with no change in adverse events, and this is not because of the selection of younger patients or those with fewer comorbidities. Furthermore, physician group practices were associated with greater payment reduction than hospital programs with no difference in readmission or mortality from baseline for either. Physicians may be a more logical group than hospitals to manage payment reduction in future healthcare reform.

LEVEL OF EVIDENCE

Level II, economic and decision analysis.

Medicaid Payer Status Is Associated with Increased 90-Day Morbidity and Resource Utilization Following Primary Total Hip Arthroplasty: A Propensity-Score-Matched Analysis

BACKGROUND

Medicaid payer status has been shown to affect risk-adjusted outcomes and resource utilization across multiple medical specialties. The purpose of this study was to examine resource utilization via readmission rates, length of stay, and total cost specific to Medicaid payer status following primary total hip arthroplasty.

METHODS

The Nationwide Readmissions Database (NRD) was utilized to identify patients who underwent total hip arthroplasty in 2013 as well as corresponding "Medicaid" or "non-Medicaid" payer status. Demographic data, 14 individual comorbidities, readmission rates, length of stay, and direct cost were evaluated. A propensity-score-based matching model was utilized to control for baseline confounding variables between payer groups. Following propensity-score matching, the chi-square test was used to compare readmission rates between the 2 payer groups. The relative risk (RR) with 95% confidence interval (CI) was estimated to quantify readmission risk. Length of stay and total cost comparisons were evaluated using the Wilcoxon signed-rank test.

RESULTS

A total of 5,311 Medicaid and 144,814 non-Medicaid patients managed with total hip arthroplasty were identified from the 2013 NRD. A propensity score was estimated for each patient on the basis of the available baseline demographics, and 5,311 non-Medicaid patients were matched by propensity score to the 5,311 Medicaid patients. Medicaid versus non-Medicaid payer status yielded significant differences in overall readmission rates of 28.8% versus 21.0% (p < 0.001; RR = 1.37 [95% CI, 1.28 to 1.46]) and 90-day hip-specific readmission rates of 2.5% versus 1.8% (p = 0.01; RR = 1.38 [95% CI, 1.07 to 1.78]). Mean length of stay was greater in the Medicaid group than in the non-Medicaid group at 4.5 versus 3.3 days (p < 0.0001), as was the mean total cost at $71,110 versus $65,309 (p < 0.0001).

CONCLUSIONS

This study demonstrates that Medicaid payer status is independently associated with increased resource utilization, including readmission rates, length of stay, and total cost following primary total hip arthroplasty. Providers may have a disincentive to treat patient populations who require increased resource utilization following surgery. Risk adjustment models accounting for Medicaid payer status are necessary to avoid decreased access to care for this patient population and to avoid financial penalty for physicians and hospitals alike.

LEVEL OF EVIDENCE

Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

No Difference in Total Episode-of-Care Cost Between Staged and Simultaneous Bilateral Total Joint Arthroplasty

BACKGROUND

Due to concerns about higher complication rates, surgeons debate whether to perform simultaneous bilateral total joint arthroplasty (BTJA), particularly in the higher-risk Medicare population. Advances in pain management and rehabilitation protocols have called into question older studies that found an overall cost benefit for simultaneous procedures. The purpose of this study was to compare 90-day episode-of-care costs between staged and simultaneous BTJA among Medicare beneficiaries.

METHODS

We retrospectively reviewed a consecutive series of 319 simultaneous primary TJAs and 168 staged TJAs (336 procedures) at our institution between 2015 and 2016. We recorded demographics, comorbidities, readmission rates, and 90-day episode-of-care costs based upon Centers for Medicare and Medicaid Services claims data. To control for confounding variables, we performed a multivariate regression analysis to identify independent risk factors for increased costs.

RESULTS

Simultaneous patients had decreased inpatient facility costs ($19,402 vs $23,025, P < .001), increased post-acute care costs ($13,203 vs $10,115, P < .001), and no difference in total episode-of-care costs ($35,666 vs $37,238, P = .541). Although there was no difference in readmissions (8% vs 9%, P = .961), simultaneous bilateral patients were more likely to experience a thromboembolic event (2% vs 0%, P = .003). When controlling for demographics, procedure, and comorbidities, a simultaneous surgery was not associated with an increase in episode-of-care costs (P = .544). Independent risk factors for increased episode-of-care costs following BTJA included age ($394 per year increase, P < .001), cardiac disease ($4877, P = .025), history of stroke ($14,295, P = .010), and liver disease ($12,515, P = .016).

CONCLUSION

In the Medicare population, there is no difference in 90-day episode-of-care costs between simultaneous and staged BTJA. Surgeons should use caution in performing a simultaneous procedure on older patients or those with a history of stroke, cardiac, or liver disease.

Machine Learning and Primary Total Knee Arthroplasty: Patient Forecasting for a Patient-Specific Payment Model

BACKGROUND

Value-based and patient-specific care represent 2 critical areas of focus that have yet to be fully reconciled by today's bundled care model. Using a predictive naïve Bayesian model, the objectives of this study were (1) to develop a machine-learning algorithm using preoperative big data to predict length of stay (LOS) and inpatient costs after primary total knee arthroplasty (TKA) and (2) to propose a tiered patient-specific payment model that reflects patient complexity for reimbursement.

METHODS

Using 141,446 patients undergoing primary TKA from an administrative database from 2009 to 2016, a Bayesian model was created and trained to forecast LOS and cost. Algorithm performance was determined using the area under the receiver operating characteristic curve and the percent accuracy. A proposed risk-based patient-specific payment model was derived based on outputs.

RESULTS

The machine-learning algorithm required age, race, gender, and comorbidity scores ("risk of illness" and "risk of morbidity") to demonstrate a high degree of validity with an area under the receiver operating characteristic curve of 0.7822 and 0.7382 for LOS and cost. As patient complexity increased, cost add-ons increased in tiers of 3%, 10%, and 15% for moderate, major, and extreme mortality risks, respectively.

CONCLUSION

Our machine-learning algorithm derived from an administrative database demonstrated excellent validity in predicting LOS and costs before primary TKA and has broad value-based applications, including a risk-based patient-specific payment model.

Race, Bundled Payment Policy, and Discharge Destination After TKA: The Experience of an Urban Academic Hospital

Background

Total knee arthroplasty (TKA) provides good clinical outcomes for the treatment of end-stage osteoarthritis; however, discharge destination after TKA has major implications on postoperative adverse outcomes and readmissions. With the initiation of Bundled Payments for Care Improvement (BPCI), it is unclear how racial disparities in discharge destination after TKA will be affected by the new bundled payment for TKA.

Methods

Bundled Payments for Care Improvement was implemented in July 01, 2014, at the University of Pennsylvania. We compared differences during early implementation (July 1, 2014, to, March 30, 2016) and during late policy implementation (April 1, 2016, to February 28, 2017) in patient characteristics (including race: African American [AA], white, and other race), discharge destination (skilled nursing facility [SNF], inpatient rehabilitation facility, home, home with home health, or other), and outcomes.

Results

We identified 2276 patients who underwent TKA (43.8% AA, 48.2% white, and 8.0% other race). African American patients were more likely to be discharged to SNF as opposed to home than white patients both during the early BPCI (AA: 53.0%, n = 320; white: 32.4%, n = 210, P < .05) and late BPCI implementation (AA: 44.4%, n = 169, white: 26.9%, n = 120, P < .05), though all races showed trends to decreasing SNF use during the late BPCI implementation.

Discussion

There were no significant differences in readmissions, length of stay, mortality, or intensive care unit days during early and late implementation of BPCI or when AA patients were compared to white patients.

Conclusion

We found no significant changes in racial variations in discharge destination and outcomes after elective TKA. Bundled Payments for Care Improvement has encouraged better preoperative preparation of patients and discharge planning; however, payment reforms alone might not be sufficient to address variation in post-op management following elective surgery.

Variation in Use of Postoperative Precautions and Equipment Following Total Hip Arthroplasty: A Survey of the AAHKS and CAS Membership

BACKGROUND

A traditional method to reduce dislocation risk following total hip arthroplasty involves prescribing postoperative precautions and ambulatory equipment to patients. The purpose of this study was to determine the prevalence of postoperative precaution and equipment use among North American arthroplasty surgeons for patients undergoing primary total hip arthroplasty.

METHODS

We conducted a survey of American Association of Hip and Knee Surgeons and Canadian Arthroplasty Society members using an electronic questionnaire format to determine how often precautions and equipment were prescribed, and whether their use was associated with surgical approach and other surgeon demographics.

RESULTS

Of the respondents, 44% universally prescribed precautions while 33% never prescribed precautions. Use of the posterolateral approach, surgeon experience, and larger head size use were significantly associated (P < .01) with precaution and equipment use. Direct anterior approach surgeons were significantly less likely to prescribe precautions (P < .0001) and significantly less likely to prescribe equipment (P < .0001).

CONCLUSION

Although postoperative precautions continue to be used to some degree by the majority of members, their consumption of healthcare resources through utilization of additional care providers and purchasing of equipment, known association with reduced patient satisfaction, and lack of supporting evidence make them a target for future scrutiny.

Risk Adjustment Is Necessary in Value-based Outcomes Models for Infected TKA

BACKGROUND

The Medicare Access and CHIP Reauthorization Act of 2015 provides the framework to link reimbursement for providers based on outcome metrics. Concerns exist that the lack of risk adjustment for patients undergoing revision TKA for an infection may cause problems with access to care.

QUESTIONS/PURPOSES

(1) After controlling for confounding variables, do patients undergoing revision TKA for infection have higher 30-day readmission, reoperation, and mortality rates than those undergoing revision TKA for aseptic causes? (2) Compared with patients undergoing revision TKA who are believed not to have infections, are patients undergoing revision for infected TKAs at increased risk for complications?

METHODS

We queried the American College of Surgeons National Surgical Quality Improvement Program database for patients undergoing revision TKA from 2012 to 2015 identified by Current Procedural Terminology (CPT) codes 27486, 27487, and 27488. Of the 10,848 patients identified, four were excluded with a diagnosis of malignancy (International Classification of Diseases, 9th Revision code 170.7, 170.9, 171.8, or 198.5). This validated, national database records short-term outcome data for inpatient procedures and does not rely on administrative coding data. Demographic variables, comorbidities, and outcomes were compared between patients believed to have infected TKAs and those undergoing revision for aseptic causes. A multivariate logistic regression analysis was performed to identify independent factors associated with complications, readmissions, reoperations, and mortality.

RESULTS

After controlling for demographic factors and medical comorbidities, TKA revision for infection was independently associated with complications (odds ratio [OR], 3.736; 95% confidence interval [CI], 3.198-4.365; p < 0.001), 30-day readmission (OR, 1.455; 95% CI, 1.207-1.755; p < 0.001), 30-day reoperation (OR, 1.614; 95% CI, 1.278-2.037; p < 0.001), and 30-day mortality (OR, 3.337; 95% CI, 1.213-9.180; p = 0.020). Patients with infected TKA had higher rates of postoperative infection (OR, 3.818; 95% CI, 3.082-4.728; p < 0.001), renal failure (OR, 36.709; 95% CI, 8.255-163.231; p < 0.001), sepsis (OR, 7.582; 95% CI, 5.529-10.397; p < 0.001), and septic shock (OR, 3.031; 95% CI, 1.376-6.675; p = 0.006).

CONCLUSIONS

Policymakers should be aware of the higher rate of mortality, readmissions, reoperations, and complications in patients with infected TKA. Without appropriate risk adjustment or excluding these patients all together from alternative payment and quality reporting models, fewer providers will be incentivized to care for patients with infected TKA.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Are Medicare's "Comprehensive Care for Joint Replacement" Bundled Payments Stratifying Risk Adequately?

BACKGROUND

Bundled payments are meant to reduce costs and improve quality of care. Without adequate risk adjustment, bundling may be inequitable to providers and restrict access for certain patients. This study examines patient factors that could improve risk stratification for the Comprehensive Care for Joint Replacement (CJR) bundled-payment program.

METHODS

Ninety-five thousand twenty-four patients meeting the CJR criteria were retrospectively reviewed using administrative Medicare data. Multivariable regression was used to identify associations between patient factors and traditional (fee-for-service) Medicare reimbursement over the bundle period.

RESULTS

Average reimbursement was $18,786 ± $12,386. Older age, male gender, cases performed for hip fractures, and most comorbidities were associated with higher reimbursement (P < .05), except dementia (lower reimbursement; P < .01). Stratification incorporating these factors displayed greater accuracy than the current CJR risk adjustment methods (R² = 0.23 vs 0.17).

CONCLUSION

More robust risk stratification could provide more equitable reimbursement in the CJR program.

LEVEL OF EVIDENCE

Large database analysis; Level III.

Risk Adjustment Is Necessary in Medicare Bundled Payment Models for Total Hip and Knee Arthroplasty

BACKGROUND

Concerns exist that high-risk patients in alternative payment models may face difficulties with access to care without proper risk adjustment. The purpose of this study is to identify the effect of medical and orthopedic specific risk factors on the cost of a 90-day episode of care following total hip (THA) and knee arthroplasty (TKA).

METHODS

We queried the Medicare 5% Limited Data Set for all patients undergoing primary THA and TKA from 2010 to 2014. To evaluate the cost of an episode of care, we calculated all claims for 90 days following surgery. Multivariate analysis was performed to quantify the added episode-of-care costs for demographic variables, geography, medical comorbidities, and orthopedic specific risk factors.

RESULTS

Of the 58,809 TKA patients, the median 90-day Medicare costs was $23,800 (interquartile range, $18,900-$32,300), while the median of the 27,293 THA patients was $24,000 (interquartile range, $18,500-$33,900). Independent risk factors (all P < .05) resulting in at least a 10% increase in episode-of-care costs following TKA included malnutrition, age over 85, male gender, pulmonary disorder, failed internal fixation, Northeast region, lower socioeconomic status, neurologic disorder, and rheumatoid arthritis. Independent risk factors (all P < .05) resulting in at least a 10% increase in episode-of-care costs following THA included malnutrition, male gender, age over 85, failed internal fixation, hip dysplasia, Northeast region, neurologic disorder, lower socioeconomic status, conversion THA, avascular necrosis, and depression.

CONCLUSION

Certain comorbidities and orthopedic risk factors increase 90-day episode-of-care costs in the Medicare population. The current lack of proper risk stratification could be a powerful driver of decreased access to care for our most medically challenged members of society.

Medicaid is associated with increased readmission and resource utilization after primary total knee arthroplasty: a propensity score-matched analysis

Background

Medicaid payer status has been shown to affect resource utilization across multiple medical specialties. There is no large database assessment of Medicaid and resource utilization in primary total knee arthroplasty (TKA), which this study sets out to achieve.

Methods

The Nationwide Readmissions Database was used to identify patients who underwent TKA in 2013 and corresponding “Medicaid” or “non-Medicaid” payer statuses. Demographics, 15 individual comorbidities, readmission rates, length of stay, and direct cost were evaluated. A propensity score–based matching model was then used to control for baseline confounding variables between payer groups. A chi-square test for paired proportions was used to compare readmission rates between the 2 groups. Length of stay and direct cost comparisons were evaluated using the Wilcoxon signed-rank test.

Results

A total of 8372 Medicaid and 268,261 non-Medicaid TKA patients were identified from the 2013 Nationwide Readmissions Database. A propensity score was estimated for each patient based on the baseline demographics, and 8372 non-Medicaid patients were propensity score matched to the 8372 Medicaid patients. Medicaid payer status yielded a statistically significant increase in overall readmission rates of 18.4% vs 14.0% (P < .0001, relative risk = 1.31, 95% confidence interval [1.23-1.41]) with non-Medicaid status and 90-day readmission rates of 10.0% vs 7.4%, respectively (P < .001, relative risk = 1.35, 95% confidence interval [1.22-1.48]). The mean length of stay was longer in the Medicaid group compared with the non-Medicaid group at 4.0 days vs 3.3 days (P < .0001) as well as the mean total cost of $64,487 vs $61,021 (P < .0001).

Conclusions

This study demonstrates that Medicaid payer status is independently associated with increased resource utilization, including readmission rates, length of stay, and total cost after TKA.

Should Medicare Remove Total Knee Arthroplasty From Its Inpatient Only List? A Total Knee Arthroplasty Is Not a Partial Knee Arthroplasty

BACKGROUND

The Centers for Medicare and Medicaid Services have solicited comments to consider removing total knee arthroplasty (TKA) from the Inpatient Only list, as it has done for unicompartmental knee arthroplasty (UKA). The purpose of this study is to determine whether Medicare-aged patients undergoing TKA had comparable outcomes to those undergoing UKA.

METHODS

We queried the American College of Surgeons-National Surgical Quality Improvement Program database for all patients aged 65 years or older who underwent elective TKA or UKA from 2014 and 2015. Demographic variables, comorbidities, length of stay (LOS), 30-day complication, and readmission rates were compared between UKA and TKA patients. A multivariate regression analysis was then performed to identify independent risk factors for complications and hospital LOS greater than 1 day.

RESULTS

Of the 50,487 patients in the study, there were 49,136 (97%) TKA patients and 1351 UKA patients (3%). Medicare-aged TKA patients had a longer mean LOS (2.97 vs 1.57 days, P < .001), had a higher complication rate (9% vs 3%, P < .001), and were more likely to be discharged to a rehabilitation facility (31% vs 9%, P < .001) than Medicare-aged UKA patients. When controlling for other variables, TKA patients were more likely to experience a complication (odds ratio, 2.562; P < .001) and require LOS >1 day (odds ratio, 14.679; P < .001) than UKA patients.

CONCLUSION

TKA procedure in the Medicare population is an independent risk factor for increased complications and LOS compared to UKA. Policymakers should use caution extrapolating UKA data to TKA patients and recognize the inherent disparities between the 2 procedures.

Do illness rating systems predict discharge location, length of stay, and cost after total hip arthroplasty?

BACKGROUND

As procedure rates and expenditures for total hip arthroplasty (THA) rise, hospitals are developing models to predict discharge location, a major determinant of total cost. The predictive value of existing illness rating systems such as the American Society for Anesthesiologists (ASA) Physical Classification System, Severity of Illness (SOI) scoring system, or Mallampati (MP) rating scale on discharge location remains unclear. This study explored the predictive role of ASA, SOI, and MP scores on discharge location, lengths of stay, and total costs for THA patients.

METHODS

A retrospective analysis of patients undergoing elective primary or revision THA was conducted at a single institution. Multivariable regressions were utilized to assess the significant predictive factors for lengths of stay, total costs, and discharge to skilled nursing facilities (SNFs), rehabilitation centers, and home. Controls included demographic factors, insurance coverage, and the type of procedure.

RESULTS

ASA scores ≥3 are the only significant predictors of discharge to SNFs (odds ratio [OR] = 1.69, confidence interval [CI] = 1.04-2.74) and home (OR = 0.57, CI = 0.34-0.98). Medicaid coverage (OR = 2.61, CI = 1.37-4.96) and African-American race (OR = 2.60, CI = 1.59-4.25) were additional significant predictors of discharge to SNF. SOI scores are the only significant predictors of length of stay (β = 1.36 days, CI = 0.53-2.19) and total cost for an episode (β = $6,234, CI = $3577-$8891). MP scores possess limited predictive power over lengths of stay only.

CONCLUSIONS

These findings suggest that although ASA classifications predict discharge location and SOI scores predict length of stay and total costs, other factors beyond illness rating systems remain stronger predictors of discharge for THA patients.

Effect of Obesity on Postacute Outcomes of Skilled Nursing Facility Residents with Hip Fracture

OBJECTIVES

To examine the effect of obesity (body mass index (BMI)≥30.0 kg/m² ) on outcomes of older adults admitted to skilled nursing facilities (SNFs) for hip fracture postacute care (PAC).

DESIGN

Retrospective cohort study.

SETTING

U.S. Medicare- and Medicaid-certified SNFs from 2008 to 2015.

PARTICIPANTS

Medicare fee-for-service beneficiaries discharged to a SNF after hospitalization for hip fracture (N=586,683; n=82,768 (14.1%) meeting obesity criteria). Exclusion criteria were aged younger than 65, being underweight (BMI<18.5 kg/m² ), and SNF use in the year prior to index hospitalization.

MEASUREMENTS

Residents were divided into 4 BMI categories according to cutoffs that the World Health Organization has established: not obese (BMI 18.5-29.9 kg/m² ), mild obesity (BMI 30.0-34.9 kg/m² ), moderate obesity (BMI 35.0-39.9 kg/m² ), and severe obesity (BMI≥40.0 kg/m² ). Robust Poisson regression was used to compare differences in average nursing facility length of stay (LOS) and rates of 30-day hospital readmission, successful discharge to community, and becoming a long-stay resident (LOS>100) according to obesity level. Models were adjusted for individual-level covariates and facility fixed effects.

RESULTS

Residents with mild (adjusted relative risk (aRR)=1.16, 95% CI=1.12-1.19), moderate (aRR=1.27, 95% CI=1.20-1.35), and severe (aRR=1.67, 95% CI=1.54-1.82) obesity were more likely to be readmitted within 30 days than those who were not obese. The average difference in LOS between residents without obesity and those with mild obesity was 2.6 days (95% CI=2.2-2.9 days); moderate obesity, 4.2 days (95% CI=3.7-5.1 days); and severe obesity, 7.0 days (95% CI=5.9-8.2 days). Residents with obesity were less likely to be successfully discharged and more likely to become long-stay nursing home residents.

CONCLUSION

Obesity was associated with worse outcomes in postacute SNF residents with hip fracture. Efforts to provide targeted care to residents with obesity may be essential to improve outcomes. Obesity may be an overlooked risk adjuster in quality-of-care measures and in payment reforms related to PAC for individuals with hip fracture.

Bundle Payment for Musculoskeletal Care: Current Evidence (Part 1)

In the face of escalating costs and variations in quality of care, bundled payment models for total joint arthroplasty procedures are becoming increasingly common, both through the Centers for Medicare & Medicaid Services and private payer organizations. The effective implementation of these payment models requires cooperation between multiple service providers to ensure economic viability without deterioration in care quality. This article introduces a stepwise model for the financial analysis of bundled contracts for use in negotiations between hospitals and private payer organizations.