Bundled Payments in Total Joint Replacement: Keeping Our Care Affordable and High in Quality

The AAHKS Clinical Research Award: Extended Oral Antibiotics Prevent Periprosthetic Joint Infection in High-Risk Cases: 3855 Patients With 1-Year Follow-Up

BACKGROUND

Surgical and host factors predispose patients to periprosthetic joint infection (PJI) after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA). While surgical factors are modifiable, host factors can be challenging, and there are limited data demonstrating that preoperative patient optimization decreases risk of PJI. The goal of this study was to evaluate whether extended oral antibiotic prophylaxis reduces the one-year infection rate in high-risk patients.

METHODS

A total of 3855 consecutive primary THAs and TKAs performed between 2011 and 2019 at a suburban academic hospital with modern perioperative and infection-prevention protocols were retrospectively reviewed. Beginning in January 2015, a 7-day oral antibiotic prophylaxis protocol was implemented after discharge for patients at high risk for PJI. The percentage of high-risk patients diagnosed with PJI within 1 year was compared between groups that did and did not receive extended antibiotic prophylaxis. Univariate and logistic regression analyses were performed, with P ≤ .05 denoting statistical significance.

RESULTS

Overall 1-year infection rates were 2.26% and 0.85% after THA and TKA, respectively. High-risk patients with extended antibiotic prophylaxis had a significantly lower rate of PJI than high-risk patients without extended antibiotic prophylaxis (0.89% vs 2.64%, respectively; P < .001). There was no difference in the infection rate between high-risk patients who received antibiotics and low-risk patients (0.89% vs 1.29%, respectively; P = .348) with numbers available.

CONCLUSION

Extended postoperative oral antibiotic prophylaxis for 7 days led to a statistically significant and clinically meaningful reduction in 1-year infection rates of patients at high risk for infection. In fact, the PJI rate in high-risk patients who received antibiotics was less than the rate seen in low-risk patients. Thus, extended oral antibiotic prophylaxis may be a simple measure to effectively counteract poor host factors. Moreover, the findings of this study may mitigate the incentive to select healthier patients in outcome-based reimbursement models. Further study with a multicenter randomized control trial is needed to further validate this protocol.

LEVEL OF EVIDENCE

Therapeutic level III.

A Single-Center Randomized Prospective Study Investigating the Efficacy of Various Wound Closure Devices in Reducing Postoperative Wound Complications

Background

Sutures and staples are the mainstay wound closure techniques in total joint arthroplasty. Newer techniques such as zipper devices and novel skin adhesives have emerged because of their potential to decrease operative time and possibly minimize complications. The aim of this study is to compare these newer techniques against conventional sutures with respect to wound complications, closure time, and costs.

Methods

A single-center randomized control trial was conducted on 160 patients (52 zipper, 55 suture, 53 mesh) who underwent primary total hip or knee arthroplasty between February 2017 and May 2018. Patients were divided into 3 closure groups: zipper device, monofilament suture plus adhesive, and monofilament plus polyester mesh with adhesive. The primary endpoint was closure time (superficial skin layer). Secondarily we collected perioperative complication rates, including infection, persistent (14-day) wound drainage, 90-day readmission, and emergency room visit rates as well as compared material costs.

Results

There were no differences in baseline characteristics between groups for age, body mass index, and American Society of Anesthesiologists classification. There was a trend toward decreased time to closure for the suture group. There were no significant differences between groups for our secondary endpoint, complications.

Conclusions

Our study shows that the suture group trended toward shorter closure time but suggests that each of the closure methods after total joint arthroplasty has equivalent complication rates. With small differences in closure time and no significant differences in complications, the decision to use one wound closure device or technique over another should be driven by institutional costs and provider familiarity.

Perception of Risk: A Poll of American Association of Hip and Knee Surgeons Members

BACKGROUND

Providers of total hip and knee replacements are being judged regarding quality/cost by payers using competition-based performance measures with poor medical and no socioeconomic risk adjustment. Providers might assume that other providers shed risk and the perception of added risk can influence practice. A poll was collected to examine such perceptions.

METHODS

In 2019 a poll was sent to the 2800 surgeon members of the American Association of Hip and Knee Surgeons using Survey Monkey while protecting respondent anonymity/confidentiality. The questions asked whether the perception of poorly risk-adjusted medical comorbidities and socioeconomic risk factors influence surgeons to selectively offer surgery.

RESULTS

There were 474 surgeon responses. Prior to elective total hip arthroplasty/total knee arthroplasty, 95% address modifiable risk factors; 52% require a body mass index <40, 64% smoking cessation, 96% an adequate hemoglobin A1C; 82% check nutrition; and 63% expect control of alcohol 2. Due to lack of socioeconomic risk adjustment, 83% reported feeling pressure to avoid/restrict access to patients with limited social support, specifically the following: Medicaid/underinsured, 81%; African Americans, 29%; Hispanics/ethnicities, 27%; and low socioeconomic status, 73%. Of the respondents, 93% predicted increased access to care with more appropriate risk adjustment.

CONCLUSION

Competition-based quality/cost performance measures influence surgeons to focus on medical risk factors in offering lower extremity arthroplasty. The lack of socioeconomic risk adjustment leads to perceptions of added risk from such factors as well. This leads to marginal loss of access for patients within certain medical and socioeconomic classes, contributing to existing healthcare disparities. This represents an unintended consequence of competition-based performance measures.

Is There a Need for Recovery Room Radiographs Following Uncomplicated Primary Total Knee Arthroplasty?

Introduction

Total knee arthroplasty (TKA) is one of the most common orthopedic procedures performed in the United States. Obtaining radiographs in the post-anesthesia care unit (PACU) has been the standard of care at most hospitals. The purpose of this study was to examine the utility and cost-effectiveness of immediate, postoperative radiographs in regards to operative decision-making to prevent complications within 90 days after primary TKA.

Methods

A retrospective review of 4,830 consecutive patients who underwent cemented or uncemented TKA between January 2016 and June 2019 at a large, regional medical center was performed. International Classification of Diseases, Tenth Revision (ICD-10) codes were used to track any readmissions within 90 days of TKA. If readmission was for a mechanical complication, including fracture, dislocation, or component loosening, PACU radiographs were reviewed for any abnormalities that may have prevented readmission.

Results

There were 195 readmissions (195 patients), of which 17 were due to mechanical complications. There was no evidence of fracture or abnormality appreciated on any of the reviewed PACU radiographs by either the reading radiologist or the senior authors. Assuming all fractures were noted on immediate, postoperative radiographs, the cost associated with identifying a single fracture in 2,415 patients was $1,072,260.

Conclusion

Routine radiographs in the recovery room after an uncomplicated primary TKA are not a reliable mechanism for preventing mechanical complications and do not alter patient care.

A clinical review of robotic navigation in total knee arthroplasty: historical systems to modern design

Robotic-assisted total knee arthroplasty (RA-TKA) has shown improved reproducibility and precision in mechanical alignment restoration, with improvement in early functional outcomes and 90-day episode of care cost savings compared to conventional TKA in some studies. However, its value is still to be determined.

Current studies of RA-TKA systems are limited by short-term follow-up and significant heterogeneity of the available systems.

In today’s paradigm shift towards an increased emphasis on quality of care while curtailing costs, providing value-based care is the primary goal for healthcare systems and clinicians. As robotic technology continues to develop, longer-term studies evaluating implant survivorship and complications will determine whether the initial capital is offset by improved outcomes.

Future studies will have to determine the value of RA-TKA based on longer-term survivorships, patient-reported outcome measures, functional outcomes, and patient satisfaction measures.

Cite this article: EFORT Open Rev 2021;6:252-269. DOI: 10.1302/2058-5241.6.200071

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.

Natural Language Processing of Patient-Experience Comments After Primary Total Knee Arthroplasty

BACKGROUND

There is interest in improving patient experience after total knee arthroplasty (TKA) due to recent shifts toward value-based medicine. Patient narratives are a valuable but unexplored source of information.

METHODS

Records of 319 patients who had undergone primary TKA between August 2016 and August 2019 were linked with vendor-supplied patient satisfaction data, which included patient comments and the Press Ganey satisfaction survey. Using machine-learning-based natural language processing, 1048 patient comments were analyzed for sentiment and classified into themes. Postoperative outcomes, patient-reported outcome measures, and traditional measures of satisfaction were compared between patients who provided a negative comment vs those who did not (positive, neutral, mixed grouped together). Multivariable regression was used to determine perioperative variables associated with providing a negative comment.

RESULTS

Of the 1048 patient comments, 25% were negative, 58% were positive, 8% were mixed, and 9% were neutral. Top 2 themes of negative comments were room condition (25%) and inefficient communication (23%). There were no differences in most of the studied outcomes (eg, peak pain intensity, length of stay, or Knee Injury and Osteoarthritis Outcome Score Junior and pain scores at 6-week follow-up) between the 2 cohorts (P > .05). However, patients who made negative comments were less likely to highly recommend their hospital care to peers (P < .001). Finally, patients who had higher American Society of Anesthesiologists Score and those who received a scopolamine patch were more likely to provide negative comments (P < .05).

CONCLUSION

Although the current study showed that patient satisfaction might not be a proxy for traditional objective perioperative outcomes, efforts to improve the nontechnical aspects of medicine are still crucial in providing patient-centered care.

Health Care Utilization and Payer Cost Analysis of Robotic Arm Assisted Total Knee Arthroplasty at 30, 60, and 90 Days

This study performed a health care utilization analysis between robotic arm assisted total knee arthroplasty (rTKA) and manual total knee arthroplasty (mTKA) techniques. Specifically, we compared (1) index costs and (2) discharge dispositions, as well as (3) 30-day (4) 60-day, and (5) 90-day (a) episode-of-care costs, (b) postoperative health care utilization, and (c) readmissions. The 100% Medicare Standard Analytical Files were used for rTKAs and mTKAs performed between January 1, 2016, and March 31, 2017. Based on strict inclusion-exclusion criteria and 1:5 propensity score matching, 519 rTKA and 2,595 mTKA patients were analyzed. Total episode payments, health care utilization, and readmissions, at 30-, 60-, and 90-day time points were compared using generalized linear model, binomial regression, log link, Mann-Whitney, and Pearson's chi-square tests. The rTKA versus mTKA cohort average total episode payment was US$17,768 versus US$19,899 (p < 0.0001) at 30 days, US$18,174 versus US$20,492 (p < 0.0001) at 60 days, and US$18,568 versus US$20,960 (p < 0.0001) at 90 days. At 30 days, 47% fewer rTKA patients utilized skilled nursing facility (SNF) services (13.5 vs. 25.4%; p < 0.0001) and had lower SNF costs at 30 days (US$6,416 vs. US$7,732; p = 0.0040), 60 days (US$6,678 vs. US$7,901, p = 0.0072), and 90 days (US$7,201 vs. US$7,947, p = 0.0230). rTKA patients also utilized fewer home health visits and costs at each time point (p < 0.05). Additionally, 31.3% fewer rTKA patients utilized emergency room services at 30 days postoperatively and had 90-day readmissions (5.20 vs. 7.75%; p = 0.0423). rTKA is associated with lower 30-, 60-, and 90-day postoperative costs and health care utilization. These results are of marked importance given the emphasis to contain and reduce health care costs and provide initial economic insights into rTKA with promising results.

Is There Value in Pathology Specimens in Routine Total Hip and Knee Arthroplasty?

Background Routine analysis of bone specimens in total joint arthroplasty (TJA) is mandatory at many institutions. The purpose of this study was to determine if mandatory routine TJA specimen analysis alters patient care or if they represent an unnecessary healthcare expenditure. Methods A retrospective review was performed of all primary TJA patients between October 2015 and December 2017 at our institution. Pathology results were reviewed to ascertain the number of concordant, discrepant, and discordant results. A diagnosis was considered concordant if the preoperative and pathologic diagnosis matched, discrepant if the preoperative and pathological diagnosis differed but no change in the patient's plan of care occurred, and discordant if the preoperative and pathologic diagnosis differed and resulted in a change in the patient's plan of care.  Results 3,670 total hip arthroplasty (THA) and total knee arthroplasty (TKA) procedures (3,613 patients) met the inclusion criteria and were included in this study. All 3,670 specimens had a concordant diagnosis; there were zero discrepant and zero discordant diagnoses. During the study period, our institution spent $67,246.88 in routine analysis of TJA specimens by a pathologist, with no change in any postoperative patient care plans. Conclusion With bundled payment reimbursement models and hospitals trying to decrease unnecessary expenditures, the present study helps further demonstrate that routine analysis has limited cost-effectiveness due to the low prevalence of alteration in the management of patient care. The decision for pathological analysis should be left at the discretion of the surgeon in order to maximize the cost-efficiency of TJA procedures.

A Case Complexity Modifier Is Warranted for Primary Total Knee Arthroplasty

BACKGROUND

The Center for Medicare and Medicaid Services is faced with a challenge of decreasing the cost of care for total knee arthroplasty (TKA) but must make efforts to prevent patient selection bias in the process. Currently, no appropriate modifier codes exist for primary TKA based on case complexity. We sought to determine differences in perioperative parameters for patients with complex primary TKA with the hypothesis that they would require increased cost of care, prolonged care times, and have worse postoperative outcome metrics.

METHODS

We performed a single-center retrospective review from 2015 to 2018 of all primary TKAs. Patient demographics, medial proximal tibial angle (mPTA), lateral distal femoral angle (lDFA), flexion contracture, cost of care, and early postoperative outcomes were collected. Complex patients were defined as those requiring stems or augments, and multivariable logistic regression analysis and propensity score matching were performed to evaluate perioperative outcomes.

RESULTS

About 1043 primary TKAs were studied, and 84 patients (8.3%) were deemed complex. For this cohort, surgery duration was greater (P < .001), cost of care higher (P < .001), and patients had a greater likelihood for 90-day hospital return. Deviation of mPTA and lDFA was significantly greater preoperatively before and after propensity score matching. Cut point analysis demonstrated that preoperative mPTA <83^o or >91^o, lDFA <84^o or >90^o, flexion contracture >10^o, and body mass index >35.7 were associated with complex procedures.

CONCLUSION

Complex primary TKA may be identifiable preoperatively and those cases associated with prolonged operative time, excess hospital cost of care, and increased 90-day hospital returns. This should be considered in future reimbursement models to prevent patient selection bias, and a complexity modifier is warranted.

Impact of Diabetes on 90-Day Episodes of Care After Elective Total Joint Arthroplasty Among Medicare Beneficiaries

BACKGROUND

In an effort to improve quality and reduce costs, reimbursement for total knee arthroplasty (TKA) and total hip arthroplasty (THA) in the United States is being based on the value of care provided, with adjustments for some qualifying comorbidities, including diabetes in its most severe form and excluding many diabetes codes. The aims of this study were to examine the effects of diabetes on elective TKA or THA complications and readmission risks among Medicare beneficiaries.

METHODS

Complication (n = 521,230) and readmission (n = 515,691) data were extracted from Medicare files in 2013 and 2014. Diabetes status (no diabetes, controlled-uncomplicated diabetes, controlled-complicated diabetes, and uncontrolled diabetes) was identified with ICD-9 (International Classification of Diseases, 9th Revision) codes. TKA or THA complications and readmission odds based on diabetes status were estimated using logistic regression and adjusted for sociodemographic and clinical characteristics, including comorbidities.

RESULTS

Compared with no diabetes, the odds ratio (OR) of TKA complications was significantly higher for uncontrolled diabetes (1.29, 95% confidence interval [CI] = 1.06 to 1.57). The OR of THA complications was significantly higher for controlled-complicated diabetes (1.45, 95% CI = 1.17 to 1.80). The OR of readmission was significantly higher for all diabetes groups (1.21 to 1.48 for TKA, 1.20 to 1.70 for THA).

CONCLUSIONS

Readmission odds were higher in all diabetes categories. The uncontrolled-diabetes group had the greatest TKA readmission and complication odds. The controlled-complicated diabetes group had the greatest THA readmission and complication odds. The findings suggest that including diabetes and associated systemic complications in cost adjustments in alternative payment models for arthroplasty should be considered.

LEVEL OF EVIDENCE

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

How to Develop a Fair Revision Arthroplasty Bundle? Using Perioperative Complications and Readmissions to Investigate

BACKGROUND

The next frontier for value-based health care in total joint arthroplasty is revision surgery. Although the disparity in health care utilization between revision procedures compared with primary total hip and total knee arthroplasty (THA/TKA) procedures is recognized, no agreement regarding the risk adjustment necessary to make revision bundles fair to both payors and providers exists. The purpose of this study is to use the risk of perioperative complications and readmissions of patients undergoing revision THA/TKA to establish the foundations of a fair revision arthroplasty bundle.

METHODS

We retrospectively evaluated a consecutive series of 484 aseptic THA/TKA revisions performed at our institution over a 12-month period and compared complications, length of stay, reoperations, and 90-day readmissions to a group of 802 consecutive patients undergoing primary THA/TKA.

RESULTS

169 (34.9%) patients experienced major complications after revision THA/TKA compared with 176 (21.9%) patients undergoing primary THA/TKA (P < .001), (OR 1.91 CI 1.49-2.45, P < .001). Patients undergoing revision TKA were 3.64 times more likely to require hospitalization greater than 3 days (OR 2.59-5.12, CI 95%, P < .001), whereas patients undergoing revision THA were 4.46 times more likely to require hospitalization greater than 3 days (OR 2.89-6.87, CI 95%, P < .001). Revision patients were 3X more likely to have a 90-day readmission and 4X more likely to have a reoperation.

CONCLUSION

For a revision bundle to be fair and widely adopted, either significant financial incentive must be instituted or the latitude given to exclude outliers from the final reconciliation. This must be adjusted to not disincentivize institutions from providing care for failed hip and knee arthroplasties.

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.

Ninety-Day Readmission in Elective Revision Lumbar Fusion Surgery in the Inpatient Setting

STUDY DESIGN

Retrospective review.

OBJECTIVES

(1) Identify the 90-day rate of readmission following revision lumbar fusion, (2) identify independent risk factors associated with increased rates of readmission within 90 days, (3) and identify the hospital costs associated with revision lumbar fusion and subsequent readmission within 90 days.

METHODS

Utilizing 2014 data from the Nationwide Readmissions Database, patients undergoing elective revision lumbar fusion were identified. With this sample, multivariate logistic regression was utilized to identify independent predictors of readmission within 90 days. An analysis of total hospital costs was also conducted.

RESULTS

In 2014, an estimated 14 378 patients underwent elective revision lumbar fusion. The readmission rate at 90 days was 3.1% (n = 446). Diabetes with chronic complications was the only comorbidity found to carry significantly increased odds of readmission. Surgical complications such as deep venous thrombosis, surgical wound disruption, hematoma, and pneumonia (experienced during the index admission) were also independent predictors of readmission. Anterior approaches were associated with increased odds of readmission. The most common related diagnoses on readmission were hardware issues, postoperative infection, and disc herniation. Readmissions were associated with an average of $96 152 in increased hospital costs per patient compared with those not readmitted.

CONCLUSION

Relevant patient comorbidities and surgical complications were associated with increased readmission within 90 days. Readmission within 90 days was associated with significant increases in hospital costs.

Polymer colloids as drug delivery systems for the treatment of arthritis

The most common types of arthritis are osteoarthritis (OA) and rheumatoid arthritis (RA) which are themain causes of disability and pain among older people. Current treatment of arthritis mainly consists of oral and intra-articular medications. Despite the efficacy of the intraarticular injections over the oral treatment, it is still limited by the rapid clearance of the injected drug. Therefore, a rational design of drug delivery systems (DDSs) able to delivery drugs in controlled manner and for required period of time to the arthritis joint is a key in developing safe and effective formulations for OA and RA. In this paper various colloidal systems like nanoparticles, liposomes, cationic carriers, hydrogels, and emulsion-based carriers were presented and discussed in light of their use and efficacy as delivery systems to transport therapeutics for arthritis treatment. Factors influencing the delivery efficacy such as size, charge, structure, drug uptake, retention and its release profile alongside with cytocompatibility and safety were addressed. Moreover, the advantages and disadvantages of the different colloidal systems were emphasised.

A Portable System for Remote Rehabilitation Following a Total Knee Replacement: A Pilot Randomized Controlled Clinical Study

Rehabilitation has been shown to improve functional outcomes following total knee replacement (TKR). However, its delivery and associated costs are highly variable. The authors have developed and previously validated the accuracy of a remote (wearable) rehabilitation monitoring platform (interACTION). The present study’s objective was to assess the feasibility of utilizing interACTION for the remote management of rehabilitation after TKR and to determine a preliminary estimate of the effects of the interACTION system on the value of rehabilitation. Specifically, we tested post-operative outpatient rehabilitation supplemented with interACTION (n = 13) by comparing it to a standard post-operative outpatient rehabilitation program (n = 12) using a randomized design. Attrition rates were relatively low and not significantly different between groups, indicating that participants found both interventions acceptable. A small (not statistically significant) decrease in the number of physical therapy visits was observed in the interACTION Group, therefore no significant difference in total cost could be observed. All patients and physical therapists in the interACTION Group indicated that they would use the system again in the future. Therefore, the next steps are to address the concerns identified in this pilot study and to expand the platform to include behavioral change strategies prior to conducting a full-scale randomized controlled trial. Trial registration: ClinicalTrials.gov NCT02646761 “interACTION: A Portable Joint Function Monitoring and Training System for Remote Rehabilitation Following TKA” 6 January 2016.

Patient-Reported Outcome Measures (Pain, Function, and Quality of Life) After Aseptic Revision Total Knee Arthroplasty

BACKGROUND

Despite the growing frequency of revision total knee arthroplasty (rTKA), there is limited information regarding patient-reported outcome measures (PROMs) after that procedure. Therefore, the purpose of this study was to determine (1) PROM improvements in pain, function, quality of life (QOL), and global health and (2) predictors of PROMs for patients undergoing aseptic rTKA as determined using a multilevel model with patients nested within surgeons.

METHODS

A prospective cohort of 246 patients who underwent aseptic rTKA from January 2016 to December 2017 and had baseline and 1-year postoperative PROMs were analyzed. The most common surgical indications were aseptic loosening (n = 109), instability (n = 73), and implant failure (n = 64). The PROMs included in this study were the Knee injury and Osteoarthritis Outcome Score (KOOS)-Pain, -Physical Function Short Form (PS), and -Quality of Life (QOL) as well as the Veterans Rand-12 (VR-12) Physical Component Summary (PCS) and Mental Component Summary (MCS). Multivariable linear regression models with patients nested within surgeons were constructed for predicting change in PROMs from baseline to 1 year.

RESULTS

The mean 1-year postoperative improvements in the KOOS-Pain and PS PROMs were 30.3 and 19.15 points, respectively, for the overall rTKA series. Improvement in the KOOS-Pain was associated with older age, baseline arthrofibrosis, lower baseline pain, and non-Medicare/Medicaid insurance and worsening of the scores was associated with multiple prior surgical procedures and instability. Improvement in the KOOS-PS was associated with baseline arthrofibrosis and female sex and worsening was associated with limited baseline function, an instability diagnosis, multiple prior surgical procedures, and increased hospital length of stay (LOS). Overall, the mean KOOS-QOL improved by 29.7 points. Although the mean VR-12 PCS improved, 54.9% of the patients saw no clinical improvement. Additionally, only 31.3% of the patients reported improvements in the VR-12 MCS. A multilevel mixed-effects model with patients/operations nested within surgeons demonstrated that the differences in the surgeons' results were minimal and explained only ∼1.86%, ∼1.12%, and ∼1.65% of the KOOS-Pain, KOOS-PS, and KOOS-QOL variance that was not explained by other predictors, respectively.

CONCLUSIONS

Overall, patients undergoing aseptic rTKA had improvements in pain, function, and QOL PROMs at 1 year. Although overall QOL improved, other global-health PROMs remained unchanged. The associations highlighted in this study can help guide the preoperative clinical decision-making process by setting expectations before aseptic rTKA.

LEVEL OF EVIDENCE

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

Costs and Outcomes of Medicare Advantage and Traditional Medicare Beneficiaries After Total Hip and Knee Arthroplasty

INTRODUCTION

Medicare Advantage (MA) has increased popularity among eligible participants by providing additional benefits from a private insurer, but these plans are omitted from several government cost savings programs, including bundled payment models. The purpose of this study was to determine whether 90-day episode-of-care (EOC) costs and outcomes were different for patients with MA plans undergoing total joint arthroplasty compared with traditional Medicare patients.

METHODS

We reviewed claims data for a consecutive series of patients undergoing primary total hip and knee arthroplasty from 2015 to 2018 at our institution with traditional Medicare coverage or MA through a single private insurer. Demographics, comorbidities, 90-day costs, readmissions, complications, and discharge disposition were compared between the groups. A multivariate regression analysis was performed to determine the independent effect of insurance status on EOC costs and outcomes.

RESULTS

Of the 10,869 patients in the study, 1,076 (9.9%) were covered under an MA plan. MA patients were more likely to be discharged to a rehabilitation facility (19% versus 14%, P < 0.0001). No significant differences were observed in length of stay (1.88 versus 1.88 days, P = 0.1439), complications (3.9% versus 3.5%, P = 0.4554), or readmissions (5.9% versus 4.9%, P = 0.1893). EOC costs were significantly higher for the MA group ($21,347 versus $19,551, P < 0.0001).

DISCUSSION

Patients with MA have higher total EOC costs than traditional Medicare beneficiaries with comparable short-term outcomes after total hip and knee arthroplasty. Further study is needed to determine whether alternative payment models in MA patients can improve care and reduce costs.

An Electronic Medical Record-Based Discharge Disposition Tool Gets Bundle Busted: Decaying Relevance of Clinical Data Accuracy in Machine Learning

Background

Determining discharge disposition after total joint arthroplasty (TJA) has been a challenge. Advances in machine learning (ML) have produced computer models that learn by example to generate predictions on future events. We hypothesized a trained ML algorithm’s diagnostic accuracy will be better than that of current predictive tools to predict discharge disposition after primary TJA.

Methods

This study was a retrospective cohort study from a single, tertiary referral center for primary TJA. We trained and validated an artificial neural network (ANN) based on 4368 distinct surgical encounters between 1/1/2013 and 6/28/2016. The ANN’s ability to identify discharge disposition was then tested on 1452 distinct surgical encounters between 1/3/17 and 11/30/17.

Results

The area under the curve and accuracy achieved during model validation were 0.973 and 91.7%, respectively, with 25% of patients being discharged to skilled nursing facilities (SNFs). Within our testing data set, 6.7% of patients went to SNFs. The performance in the testing set included an area under the curve of 0.804, accuracy of 61.3%, sensitivity of 28.9%, and specificity of 93.8%.

Conclusions

This is the first prediction tool using an electronic medical record–integrated ANN to predict discharge disposition after TJA based on locally generated data. Dramatically reduced numbers of patients discharged to SNFs due to implementation of a bundled payment model lead to poor recall in the testing model. This model serves as a proof of concept for developing an ML prediction tool using a relatively small data set and subsequent integration into the electronic medical record.

Concomitant Malnutrition and Frailty Are Uncommon, but Significant Risk Factors for Mortality and Complication Following Primary Total Knee Arthroplasty

BACKGROUND

Total knee arthroplasty (TKA) demand continues to rise, but we are also gaining greater insight into patient risk factors for postoperative complications and excess resource utilization. There has been growing interest in frailty and malnutrition as risk factors, although they are often mistakenly used interchangeably. We aimed at identifying the incidence of their coexistence, and the magnitude of risk they confer to TKA patients.

METHODS

We queried the American College of Surgeons-National Surgery Quality Improvement Program database to identify 4 patient cohorts: healthy/normal serum albumin, healthy/hypoalbuminemic patients, normoalbuminemic/medically frail patients (defined by modified frailty index), and hypoalbuminemic/frail patients. We performed both univariate and multivariate analyses to quantify the risk conferred by each condition in isolation, and in coexistence.

RESULTS

Of 179,702 elective TKA cases from 2006 to 2018, 18.6% of patients were frail only, 3.0% were hypoalbuminemic -only, and just 1.2% were both frail and hypoalbuminemic. The raw rate of any complication was highest in frail/hypoalbuminemic patients (8.7%), 5.2% in hypoalbuminemic patients, 4.8% in frail patients, and just 3.4% in healthy patients (P < .001); the multivariate model revealed odds ratio of a complication in frail/hypoalbuminemic group of 2.40 (95% confidence interval = 1.27-1.63; P < .001). Mortality within 30 days was highest in the frail/hypoalbuminemic cohort (1.0%), and just 0.1% in healthy patients, and the multivariate model noted an odds ratio of 9.43 for these patients (95% confidence interval = 5.92-14.93; P < .001). The odds of all studied complications were highest in the frail/hypoalbuminemic group.

CONCLUSION

Frailty and hypoalbuminemia represent distinct conditions and are independent risk factors for a complication after TKA. Their coexistence imparts a synergistic association with the risk of post-TKA complications.

Arthroplasty Surgeons Do Not Improve Acute Outcomes for Patients With Hip Fracture Relative to Other Subspecialists

As bundled reimbursement models continue to evolve, there is a continued effort to increase the value of care for patients undergoing arthroplasty. The authors sought to evaluate the effect of surgeon specialization (arthroplasty vs non-arthroplasty) on acute outcomes for patients with hip fracture who underwent total hip arthroplasty (THA), in an effort to determine whether the value of care can be improved by surgeons specializing in these procedures. They performed a multicenter retrospective cohort study of patients who had hip fracture and were treated with THA between June 2013 and February 2018 at 2 academic institutions that were involved in bundled reimbursement initiatives. Patients were stratified based on the subspecialty training of the operative surgeon (fellowship-trained adult reconstruction vs other orthopedic sub-specialty), and 90-day readmissions, length of stay, and discharge disposition were compared between groups. A total of 291 patients were included in the final cohort, with 120 (41.2%) undergoing surgery performed by a fellowship-trained adult reconstruction surgeon. No significant difference was found in age, sex, race, or American Society of Anesthesiologists score between the 2 groups. In addition, no significant difference was found in length of stay, discharge to a facility, or 90-day readmissions on univariable or multivariable analysis when adjusted for age, sex, body mass index, and American Society of Anesthesiologists score. This study showed that the acute outcomes used to assess the value of care for patients undergoing THA were not significantly different when the surgery was performed by an adult reconstruction specialist compared with other orthopedic surgeons at 2 high-volume academic centers with perioperative care pathways. Alternative modalities to significantly improve acute postoperative outcomes in a bundled reimbursement model must be investigated. [Orthopedics. 2020;43(5):e442-e446.].

Medicare's Bundled Payment Initiatives for Hospital-Initiated Episodes: Evidence and Evolution

Policy Points Evidence suggests that bundled payment contracting can slow the growth of payer costs relative to fee-for-service contracting, although bundled payment models may not reduce absolute costs. Bundled payments may be more effective than fee-for-service payments in containing costs for certain medical conditions. For the most part, Medicare's bundled payment initiatives have not been associated with a worsening of quality in terms of readmissions, emergency department use, and mortality. Some evidence suggests a worsening of other quality measures for certain medical conditions. Bundled payment contracting involves trade-offs: Expanding a bundle's scope and duration may better contain costs, but a more comprehensive bundle may be less attractive to providers, reducing their willingness to accept it as an alternative to fee-for-service payment.

CONTEXT

Bundled payments have been promoted as an alternative to fee-for-service payments that can mitigate the incentives for service volume under the fee-for-service model. As Medicare has gained experience with bundled payments, it has widened their scope and increased their duration. However, there have been few reviews of the empirical literature on the impact of Medicare's bundled payment programs on cost, resource use, utilization, and quality.

METHODS

We examined the history and features of 16 of Medicare's bundled payment programs involving hospital-initiated episodes of care and conducted a literature review of articles about those programs. Database and additional searches yielded 1,479 articles. We evaluate the studies' methodological quality and summarize the quantitative findings about Medicare expenditures and quality of care from 37 studies that used higher-quality research designs.

FINDINGS

Medicare's bundled payment initiatives have varied in their design features, such as episode scope and duration. Many initiatives were associated with little to no reduction in Medicare expenditures, unless large pricing discounts for providers were negotiated in advance. Initiatives that included post-acute care services were associated with lower expenditures for certain conditions. Hospitals may have been able to reduce internal production costs with help from physicians via gainsharing. Most initiatives were not associated with significant changes in quality of care, as measured by readmission and mortality rates. Of the significant changes in readmission rates, the results were mixed, showing increases and decreases associated with bundled payments. Some evidence suggested that worse patient outcomes were associated bundled payments, although most results were not statistically significant. Results on case-mix selection were mixed: Several initiatives were associated with reductions in episode severity, whereas others were associated with little change.

CONCLUSIONS

Bundled payments for hospital-initiated episodes may be a good alternative to fee-for-service payments. Bundled payments can help slow the growth of payer spending, although they do not necessarily reduce absolute spending. They are associated with lower provider production costs, and there is no overwhelming evidence of compromised quality. However, designing a bundled payment contract that is attractive to both providers and payers proves to be a challenge.

Development of Machine Learning Algorithms to Predict Clinically Meaningful Improvement for the Patient-Reported Health State After Total Hip Arthroplasty

BACKGROUND

Failure to achieve clinically significant outcome (CSO) improvement after total hip arthroplasty (THA) imposes a potential cost-to-risk imbalance in the context of bundle payment models. Patient perception of their health state is one component of such risk. The purpose of the current study is to develop machine learning algorithms to predict CSO for the patient-reported health state (PRHS) and build a clinical decision-making tool based on risk factors.

METHODS

A retrospective review of primary THA patients between 2014 and 2017 was performed. Variables considered for prediction included demographics, medical history, preoperative PRHS, and modified Harris Hip Score. The minimal clinically important difference (MCID) for the PRHS was calculated using a distribution-based method. Five supervised machine learning algorithms were developed and assessed by discrimination, calibration, Brier score, and decision curve analysis.

RESULTS

Of 616 patients, a total of 407 (69.2%) achieved the MCID for the PRHS. The random forest algorithm achieved the best performance in the independent testing set not used for algorithm development (c-statistic 0.97, calibration intercept -0.05, calibration slope 1.45, Brier score 0.054). The most important factors for achieving the MCID were preoperative PRHS, preoperative opioid use, age, and body mass index. Individual patient-level explanations were provided for the algorithm predictions and the algorithms were incorporated into an open access digital application available here: https://sorg-apps.shinyapps.io/THA_PRHS_mcid/.

CONCLUSION

The current study created a clinical decision-making tool based on partially modifiable risk factors for predicting CSO after THA. The tool demonstrates excellent discriminative capacity for identifying those at greatest risk for failing to achieve CSO in their current health state and may allow for preoperative health optimization.

Refining Risk-Adjustment of 90-Day Costs Following Surgical Fixation of Ankle Fractures: An Analysis of Medicare Beneficiaries

As the current healthcare model transitions from fee-for-service to value-based payments, identifying cost-drivers of 90-day payments following surgical procedures will be a key factor in risk-adjusting prospective bundled payments and ensuring success of these alternative payment models. The 5% Medicare Standard Analytical Files data set for 2005-2014 was used to identify patients undergoing open reduction and internal fixation (ORIF) for isolated unimalleolar, bimalleolar, and trimalleolar ankle fractures. All acute care and post-acute care payments starting from day 0 of surgery to day 90 postoperatively were used to calculate 90-day costs. Patients with missing data were excluded. Multivariate linear regression modeling was used to derive marginal cost impact of patient-level (age, sex, and comorbidities), procedure-level (fracture type, morphology, location of surgery, concurrent ankle arthroscopy, and syndesmotic fixation), and state-level factors on 90-day costs after surgery. A total of 6499 patients were included in the study. The risk-adjusted 90-day cost for a female patient, aged 65 to 69 years, undergoing outpatient ORIF for a closed unimalleolar ankle fracture in Michigan was $6949 ± $1060. Individuals aged <65 or ≥70 years had significantly higher costs. Procedure-level factors associated with significant marginal cost increases were inpatient surgery (+$5577), trimalleolar fracture (+$1082), and syndesmotic fixation (+$2822). The top 5 comorbidities with the largest marginal cost increases were chronic kidney disease (+$8897), malnutrition (+$7908), obesity (+$5362), cerebrovascular disease/stroke (+$4159), and anemia (+$3087). Higher costs were seen in Nevada (+$6371), Massachusetts (+$4497), Oklahoma (+$4002), New Jersey (+$3802), and Maryland (+$3043) compared with Michigan. With the use of a national administrative claims database, the study identifies numerous patient-level, procedure-level, and state-level factors that significantly contribute to the cost variation seen in 90-day payments after ORIF for ankle fracture. Risk adjustment of 90-day costs will become a necessity as bundled-payment models begin to take over the current fee-for-service model in patients with fractures.

The burden and utility of routine follow-up at one year after primary arthroplasty

AIMS

Routine surveillance of primary hip and knee arthroplasties has traditionally been performed with office follow-up visits at one year postoperatively. The value of these visits is unclear. The present study aims to determine the utility and burden of routine clinical follow-up at one year after primary arthroplasty to patients and providers.

METHODS

All patients (473) who underwent primary total hip (280), hip resurfacing (eight), total knee (179), and unicompartmental knee arthroplasty (six) over a nine-month period at a single institution were identified from an institutional registry. Patients were prompted to attend their routine one-year postoperative visit by a single telephone reminder. Patients and surgeons were given questionnaires at the one-year postoperative visit, defined as a clinical encounter occurring at nine to 15 months from the date of surgery, regarding value of the visit.

RESULTS

Compliance with routine follow-up at one year was 35%. The response rate was over 80% for all questions in the patient and clinician surveys. Overall, 75% of the visits were for routine surveillance. Patients reported high satisfaction with their visits despite the general time for attendance, including travel, being over four hours. Surgeons found the visits more worthwhile when issues were identified or problems were addressed.

CONCLUSION

Patient compliance with follow-up at one year postoperatively after primary hip and knee is low. Routine visits of asymptomatic patients deliver little practical value and represent a large time and cost burden for patients and surgeons. Remote strategies should be considered for routine postoperative surveillance primary hip and knee arthroplasties beyond the acute postoperative period. Cite this article: Bone Joint J 2020;102-B(7 Supple B):85-89.

Establishing an Orthopedic Excess Hospital Days in Acute Care Program

BACKGROUND

Excess days in acute care (EDAC) after total joint arthroplasty (TJA) represent a large economic burden. We developed an Orthopedic EDAC program that triages TJA patients to the appropriate service line (orthopedic vs medicine) and level of care (observation vs inpatient) on re-presentation. We developed and used evidence-based protocols for the treatment of TJA patients who are rehospitalized.

METHODS

We defined Orthopedic EDAC as the length of stay (LOS) during readmission and observation stays. Our target population included TJA and revision TJA patients. Patients between April 2017 and September 2017 and between October 2017 and September 2018 were defined as pre-implementation and post-implementation of the Orthopedic EDAC program, respectively.

RESULTS

A total of 2,662 patients underwent TJA and revision TJA during the pre-implementation and post-implementation periods. Twenty-three patients were managed on observation status during the study period. Readmissions decreased from 49 (6.1%) during pre-implementation to 37 (2.0%) during post-implementation (P = .004). By design, more rehospitalized patients were on the orthopedic surgery service after implementation of the Orthopedic EDAC program (n = 49; 70%) versus before (n = 22; 35%; P = .028). EDAC LOS decreased from 7.75 days to 4.73 days (P = .005).

CONCLUSION

In this single-center, before-after pilot of a novel Orthopedic EDAC program, we demonstrated a reduction in readmissions and Orthopedic EDAC LOS, as well as improved continuity of care for TJA patients on representation.

Risk-Adjusted Cost Performance for 90-Day Total Knee Arthroplasty Episodes: Data and Methods for Comparing U.S. Hospitals Nationwide

BACKGROUND

We propose a model to characterize the variation in total knee arthroplasty (TKA) episode payments in the U.S. Medicare population to establish a baseline prior to the full implementation of the Comprehensive Care for Joint Replacement (CJR) model.

METHODS

We identified TKA episodes in Medicare Part A (100% sample) from 2014 to 2016 (n = 717,690) and compared 90-day episode payments across years and geographic regions. We fit hierarchical models that regressed episode payments on patient-level fixed effects (age, sex, race, comorbidities) and region-level (U.S. Census Regions) and hospital-level random effects. Random-effect estimates were used to characterize risk-adjusted hospital cost performance. We ranked hospitals (n = 3,217) in each region by their cost performance estimate and constructed 95% confidence intervals to visualize high and low-performing hospitals.

RESULTS

During this period, the mean Part A episode payments declined throughout the United States ($18,665 to $16,978; p < 0.001), primarily because of decreased post-acute care payments ($6,401 to $4,873; p < 0.0001). The 90-day readmission rates fell by nearly 20% (7.2% to 5.8%; p < 0.001). We found significant variation (p < 0.05) in risk-adjusted episode payments, post-acute care utilization, and readmission rates across regions and even hospitals. The share of hospitals in each geographic region that were low-performance outliers for episode payments ranged from 13% to 31% and those that were high-performance outliers ranged from 16% to 30%.

CONCLUSIONS

Medicare Part A payments for TKA episodes were decreasing prior to the CJR model because of decreases in both post-acute care utilization and hospital readmissions. A significant variation in risk-adjusted hospital cost performance remained. Our results provide a baseline against which to measure the impact of alternative payment models and a methodology by which to measure hospital-level performance, which can be compared with peer hospitals and national benchmarks.

Hospital-Specific Total Joint Arthroplasty Casemix and Patient Flows in the Era of Payment Reform: Impact on Resource Utilization Among New York State Hospitals

BACKGROUND

Bundled payment models may lead to selection of healthier total joint arthroplasty (TJA) candidates resulting in comorbid patients being taken care of in fewer hospitals. We aimed to (1) evaluate hospital-specific TJA comorbidity burden ("casemix") over time and (2) associations with resource utilization.

METHODS

This retrospective cohort study used 2011 and 2016 New York State data (n = 36,078 hip/knee arthroplasties). Comorbidity burden was estimated by the Charlson-Deyo Index; main outcomes were hospitalization cost and nonhome discharge. Hospitals were categorized into those with a decreased, stable (with a 5% buffer), or increased percentage of comorbidity-free patients (Charlson-Deyo = 0) between 2011 and 2016. Mixed-effects models measured the association between Charlson-Deyo Index category and outcomes, by hospital casemix categorization. Odds ratios and 95% confidence intervals (CIs) are reported.

RESULTS

Overall, 29 (n = 8810), 37 (n = 16,297), and 46 (n = 10,971) hospitals were categorized into the decreased, stable, and increased Charlson-Deyo = 0 categories, respectively, with median annual TJA volumes of 499, 814, and 393 (P < .0001). Multivariable models demonstrated that-in hospitals with a stable patient casemix-increased patient comorbidity was associated with increased hospitalization costs (maximum 21.8%, CI 18.9-24.9, P < .0001). However, this effect was moderated (maximum 11.1%, CI 8.0-14.2) in hospitals that took on a more comorbid patient casemix. Similar patterns were observed for nonhome discharge.

CONCLUSION

Most studied hospitals show an increase in comorbidity-free TJA patients, suggestive of patient selection. This redistribution of comorbid patients to select hospitals may not necessarily be a negative development as our results suggest more efficient resource utilization for comorbid patients in such hospitals.

Projections and Epidemiology of Revision Hip and Knee Arthroplasty in the United States to 2030

BACKGROUND

As the incidence of primary total joint arthroplasty rises in the United States, it is important to investigate how this will impact rates of revision arthroplasty. The purpose of this study was to analyze the incidence and future projections of revision total hip arthroplasty (rTHA) and revision total knee arthroplasty (rTKA) to 2030. Anticipating surgical volume will aid surgeons in designing protocols to efficiently and effectively perform rTHA/rTKA.

METHODS

The national inpatient sample was queried from 2002 to 2014 for all rTHA/rTKA. Using previously validated measures, Poisson and linear regression analyses were performed to project annual incidence of rTHA/rTKA to 2030, with subgroup analyses on modes of failure and age.

RESULTS

In 2014, there were 50,220 rTHAs and 72,100 rTKAs. From 2014 to 2030, rTHA incidence is projected to increase by between 43% and 70%, whereas rTKA incidence is projected to increase by between 78% and 182%. The 55-64 and 65-74 age groups increased in revision incidence during the study period, whereas 75-84 age group decreased in incidence. For rTKA, infection and aseptic loosening are the 2 most common modes of failure, whereas periprosthetic fracture and infection are most common for rTHA.

CONCLUSION

The incidence of rTHA/rTKA is projected to increase, particularly in young patients and for infection. Given the known risk factor profiles and advanced costs associated with revision arthroplasty, our projections should encourage institutions to generate revision-specific protocols to promote safe pathways for cost-effective care that is commensurate with current value-based health care trends.

LEVEL OF EVIDENCE

IV.

The Association Between Newly Accredited Orthopedic Residency Programs and Teaching Hospital Complication Rates in Lower Extremity Total Joint Arthroplasty

OBJECTIVE

The influence of residency programs on teaching hospital outcomes in total joint arthroplasty (TJA) has recently been debated. This study investigates how complication and readmission rates for primary elective total hip (THA) and total knee arthroplasty (TKA) changed before and after new orthopedic surgery residency programs meeting ACGME accreditation requirements were introduced at hospitals.

DESIGN

We conducted a retrospective cohort study using the CMS Hospital Compare database, which contains hospital-level data on risk-standardized complication and readmission rates (2013-2018) for primary elective THA and TKA in Medicare beneficiaries. Orthopedic surgery residency programs that were newly accredited during this time were identified using ACGME publicly available data.

SETTING

Eight primary adult teaching hospitals with complication and readmission data in the CMS database available prior to the first full year its affiliated residency program was implemented, and with subsequent program data also available.

PARTICIPANTS

Six ACGME accredited orthopedic surgery residency programs.

RESULTS

Even after controlling for annual variation in surrounding hospital rates, the at-risk patient volume, and variation in starting rates for a given hospital in the first available year, multivariate linear regression demonstrated that complication rates for lower extremity TJA in Medicare beneficiaries decreased by 0.20 per year (R² = 0.78, p = 0.005) after hospitals introduced new orthopedic surgery residency programs meeting ACGME accreditation requirements. There were no significant differences in readmission rates after the addition of newly accredited programs to these same hospitals (R² = 0.51; p = 0.706).

CONCLUSIONS

Starting an orthopedic surgery residency program meeting ACGME accreditation requirements was associated with significantly reduced complication rates for primary elective lower extremity TJA in Medicare beneficiaries at teaching hospitals where these programs began rotating residents. These findings raise awareness regarding the potential for residency programs to contribute to improved patient care outside of the operating room as well as through direct resident involvement in procedures.

The "Hip Fracture" Bundle-Experiences, Challenges, and Opportunities

Introduction:

With growing popularity and success of alternative-payment models (APMs) in elective total joint arthroplasties, there has been recent discussion on the probability of implementing APMs for geriatric hip fractures as well.

Significance:

Despite the growing interest, little is known about the drawbacks and challenges that will be faced in a stipulated “hip fracture” bundle.

Results:

Given the varying intricacies and complexities of hip fractures, a “one-size-fits-all” bundled payment may not be an amenable way of ensuring equitable reimbursement for participating physicians and hospitals.

Conclusions:

Health-policy makers need to advocate for better risk-adjustment methods to prevent the creation of financial disincentives for hospitals taking care of complex, sicker patients. Hospitals participating in bundled care also need to voice concerns regarding the grouping of hip fractures undergoing total hip arthroplasty to ensure that trauma centers are not unfairly penalized due to higher readmission rates associated with hip fractures skewing quality metrics. Physicians also need to consider the launch of better risk-stratification protocols and promote geriatric comanagement of these patients to prevent occurrences of costly adverse events.

Surgeon Reimbursement Unchanged as Hospital Charges and Reimbursements Increase for Total Joint Arthroplasty

BACKGROUND

Despite increasing demands on physicians and hospitals to increase value and reduce unnecessary costs, reimbursement for healthcare services has been under downward pressure for several years. This study aimed to analyze the trend in hospital charges and payments relative to corresponding surgeon charges and payments in a Medicare population for total hip (THA) and knee arthroplasty (TKA).

METHODS

The 5% Medicare sample database was used to capture hospital and surgeon charges and payments related to 56,228 patients who underwent primary THA and 117,698 patients who underwent primary TKA between 2005 and 2014. Two values were calculated: (1) the charge multiplier (CM), the ratio of hospital to surgeon charges and (2) the payment multiplier (PM), the ratio of hospital to surgeon payments. Year-to-year variation and regional trends in patient demographics, Charlson Comorbidity Index, length of stay (LOS), CM, and PM were evaluated.

RESULTS

Hospital charges were significantly higher than surgeon charges and increased substantially for both THA (CM increased from 8.7 to 11.5, P < .0001) and TKA (CM increased from 7.9 to 11.4, P < .0001). PM followed a similar trend, increasing for both THA and TKA (P < .0001). LOS decreased significantly for both THA and TKA (P < .0001), while Charlson Comorbidity Index remained stable. Both CM (r² = 0.84 THA, 0.90 TKA) and PM (r² = 0.75 THA, 0.84 TKA) were strongly negatively associated with LOS.

CONCLUSION

Hospital charges and payments relative to surgeon charges and payments have increased substantially for THA and TKA despite stable patient complexity and decreasing LOS.

Are current DRG-based bundled payment models for lumbar fusions risk-adjusting adequately? An analysis of Medicare beneficiaries

BACKGROUND CONTEXT

Current bundled payment programs in spine surgery, such as the bundled payment for care improvement rely on the use of diagnosis-related groups (DRG) to define payments. However, these DRGs may not be adequate enough to appropriately capture the large amount of variation seen in spine procedures. For example, DRG 459 (spinal fusion except cervical with major comorbidity or complication) and DRG 460 (spinal fusion except cervical without major comorbidity or complication) do not differentiate between the type of fusion (anterior or posterior), the levels/extent of fusion, the use of interbody/graft/BMP, indication of surgery (primary vs. revision) or even if the surgery was being performed for a vertebral fracture.

PURPOSE

We carried out a comprehensive analysis to report the factors responsible for cost-variation in a bundled payment model for spinal fusions.

STUDY DESIGN

Retrospective review of a 5% national sample of Medicare claims from 2008 to 2014 (SAF5).

OUTCOME MEASURES

To understand the independent marginal cost impact of various patient-level, geographic-level, and procedure-level characteristics on 90-day costs for patients undergoing spinal fusions under DRG 459 and 460.

METHODS

The 2008 to 2014 Medicare 5% standard analytical files (SAF) were used to retrieve patients undergoing spinal fusions under DRG 459 and DRG 460 only. Patients with missing gender, age, and/or state-level data were excluded. Only those patients who had complete data, with regard to payments/costs/reimbursements, starting from day 0 of surgery up to 90 days postoperatively were included to prevent erroneous collection. Multivariate linear regression models were built to assess the independent marginal cost impact (decrease/increase) of each patient-level, state-level, and procedure-level characteristics on the average 90-day cost while controlling for other covariates.

RESULTS

A total of 21,367 patients (DRG-460=20,154; DRG-459=1,213) were included in the study. The average 90-day cost for all lumbar fusions was $31,716±$18,124, with the individual 90-day payments being $54,607±$30,643 (DRG-459) and $30,338±$16,074 (DRG-460). Increasing age was associated with significant marginal increases in 90-day payments (70-74 years: +$2,387, 75-79 years: +$3,389, 80-84 years: +$2,872, ≥85: +$1,627). With regards to procedure-level factors-undergoing an anterior fusion (+$3,118), >3 level fusion (+$5,648) vs. 1 to 3 level fusion, use of interbody device (+$581), intraoperative neuromonitoring (+$1,413), concurrent decompression (+$768) and undergoing surgery for thoracolumbar fracture (+$6,169) were associated with higher 90-day costs. Most individual comorbidities were associated with higher 90-day costs, with malnutrition (+$12,264), CVA/stroke (+$5,886), Alzheimer's (+$4,968), Parkinson's disease (+$4,415), and coagulopathy (+$3,810) having the highest marginal 90-day cost-increases. The top five states with the highest marginal cost-increase, in comparison to Michigan (reference), were Maryland (+$12,657), Alaska (+$11,292), California (+$10,040), Massachusetts (+$8,800), and the District of Columbia (+$8,315).

CONCLUSIONS

Under the proposed DRG-based bundled payment model, providers would be reimbursed the same amount for lumbar fusions regardless of the surgical approach (posterior vs. anterior), the extent of fusion (1-3 level vs. >3 level), use of adjunct procedures (decompressions) and cause/indication of surgery (fracture vs. degenerative pathology), despite each of these factors having different resource utilization and associated costs. When defining and developing future bundled payments for spinal fusions, health-policy makers should strive to account for the individual patient-level, state-level, and procedure-level variation seen within DRGs to prevent the creation of a financial dis-incentive in taking care of sicker patients and/or performing more extensive complex spinal fusions.

Physiatry as a Leader for Postacute Care in Integrated Healthcare Systems

Because health care is being moved to a higher level of accountability, there has been a focus on improving outcomes through improving postacute care. The issues of cost and readmissions to acute care settings are very important, but the focus on patient function has not been foremost. Because of the fact that most postacute care needs are based on functional limitations and that physiatrists are well versed in transitions of care, rehabilitation of patients back to community settings, team building, and leadership, it is appropriate for rehabilitation medicine to take a leadership role in the planning and development of postacute care services in the new integrated healthcare systems that are becoming prevalent in healthcare. This review discusses some of the issues in postacute care, the growth of the integrated health system model, and how there are opportunities and challenges for physiatric leadership to help develop these new models of care.

Trajectories of functional performance and muscle strength recovery differ after total knee and total hip replacement: a performance-based, longitudinal study

Total joint replacement is indicated to alleviate pain and disability associated with hip and knee osteoarthritis. Arthroplasty outcomes are typically reported together, or anecdotal comparisons are made between total knee arthroplasty (TKA) and total hip arthroplasty (THA) recovery. Limited data quantifies differences in recovery trajectories, especially with respect to performance-based outcomes. Seventy-nine people undergoing total knee or THA were followed over 6 months. Functional performance was measured using the stair climb test, timed-up-and-go test, and 6-min walk test. Surgical limb isometric strength was also measured. All outcomes significantly declined 1 month after surgery. Participants in the TKA group showed a greater decline in climbing stairs (P < 0.001), timed-up-and-go (P = 0.01), and 6-min walk distance (P < 0.01). Further, the TKA group lost more strength (P < 0.001) and were weaker than those after THA (P < 0.001). Differences in postoperative outcomes between groups at 3 and 6 months were also observed. The TKA group experiences a greater decline in measured outcomes than the THA group, and muscle strength and functional recovery occurred differently in each group. These findings should be considered in rehabilitation priorities after arthroplasty surgery.

Surgeon Mean Operative Times in Total Knee Arthroplasty in a Variety of Settings in a Health System

BACKGROUND

High-quality care is essential in total joint arthroplasty. Multiple initiatives such as centers of excellence, patient optimization, and alternative payment models have demonstrated improved outcomes and decreased cost. Many studies have shown that longer operative times (OTs) are associated with increased frequency of postoperative complications. These findings often come from large data sets and may not accurately represent the average OT of individual surgeons. The purpose of this study was to determine the hospital and patient-related factors that influence OT.

METHODS

This retrospective study reviewed OT of 6003 total knee arthroplasty cases performed by 41 surgeons at 4 hospitals in a single health-care system. Mean OT was calculated for each surgeon. The effect of surgeon, hospital-, and patient-related factors on OT was assessed.

RESULTS

Among the 41 surgeons, the mean OT was 105 ± 25 minutes. Two community hospitals had significantly faster OT compared with the tertiary care academic hospital. Surgeons' OT for morbidly obese patients was significantly longer compared with normal, overweight, and obese patients. Surgeon volume, surgeon experience, trainee presence, and American Society of Anesthesiologists status did not significantly affect surgical time.

CONCLUSIONS

Operative time was influenced by hospital-related (tertiary, community) and patient-related (morbid obesity vs lower body mass index groups) factors. However, specific surgeon factors (surgical volume, experience), surgical team factors (presence or absence of trainee), and patient factors (American Society of Anesthesiologists status) did not significantly alter the OT. Additional studies of larger health systems are needed to examine additional patient, surgeon, and hospital factors which may influence the OT.

Deep Learning Preoperatively Predicts Value Metrics for Primary Total Knee Arthroplasty: Development and Validation of an Artificial Neural Network Model

BACKGROUND

The objective is to develop and validate an artificial neural network (ANN) that learns and predicts length of stay (LOS), inpatient charges, and discharge disposition before primary total knee arthroplasty (TKA). The secondary objective applied the ANN to propose a risk-based, patient-specific payment model (PSPM) commensurate with case complexity.

METHODS

Using data from 175,042 primary TKAs from the National Inpatient Sample and an institutional database, an ANN was developed to predict LOS, charges, and disposition using 15 preoperative variables. Outcome metrics included accuracy and area under the curve for a receiver operating characteristic curve. Model uncertainty was stratified by All Patient Refined comorbidity indices in establishing a risk-based PSPM.

RESULTS

The dynamic model demonstrated "learning" in the first 30 training rounds with areas under the curve of 74.8%, 82.8%, and 76.1% for LOS, charges, and discharge disposition, respectively. The PSPM demonstrated that as patient comorbidity increased, risk increased by 2.0%, 21.8%, and 82.6% for moderate, major, and severe comorbidities, respectively.

CONCLUSION

Our deep learning model demonstrated "learning" with acceptable validity, reliability, and responsiveness in predicting value metrics, offering the ability to preoperatively plan for TKA episodes of care. This model may be applied to a PSPM proposing tiered reimbursements reflecting case complexity.

Defining and Optimizing Value in Total Joint Arthroplasty From the Patient, Payer, and Provider Perspectives

BACKGROUND

The purpose of this study is to define value in bundled total joint arthroplasty (TJA) from the differing perspectives of the patient, payer/employer, and hospital/provider.

METHODS

Demographic, psychosocial, clinical, financial, and patient-reported outcomes (PROs) data from 2017 to 2018 elective TJA cases at a multihospital academic health system were queried. Value was defined as improvement in PROs (preoperatively to 1 year postoperatively) for patients, improvement in PROs per $1000 of bundle cost for payers, and the normalized sum of improvement in PROs and hospital bundle margin for providers. Bivariate analysis was used to compare high value vs low value (>50th percentile vs <50th percentile). Multivariate analysis was performed to identify predictors.

RESULTS

A total of 280 patients had PRO data, of which 71 had Medicare claims data. Diabetes (odds ratio [OR], 0.45; P = .02) predicted low value for patients; female gender (OR, 0.25), hypertension (OR, 0.17), pulmonary disease (OR, 0.12), and skilled nursing facility discharge (OR, 0.17) for payers (P ≤ .03 for all); and pulmonary disease (OR, 0.16) and skilled nursing facility discharge (OR, 0.19) for providers (P ≤ .04 for all).

CONCLUSION

This is the first article to define value in TJA under a bundle payment model from multiple perspectives, providing a foundation for future studies analyzing value-based TJA.

Ninety-day and one-year healthcare utilization and costs after knee arthroplasty

OBJECTIVES

This study examined ninety-day and one-year postoperative healthcare utilization and costs following total knee arthroplasty (TKA) from the health sector and patient perspectives.

DESIGN

This study relied on: 1) patient-reported medical resource utilization data from diaries in the Knee Arthroplasty Pain Coping Skills Training (KASTPain) trial; and 2) Medicare fee schedules. Medicare payments, patient cost-sharing, and patient time costs were estimated. Generalized linear mixed models were used to identify baseline predictors of costs.

RESULTS

In the first ninety days following TKA, patients had an average of 29.7 outpatient visits and 6% were hospitalized. Mean total costs during this period summed to $3,720, the majority attributed to outpatient visit costs (84%). Over the year following TKA, patients had an average of 48.9 outpatient visits, including 33.2 for physical therapy. About a quarter (24%) of patients were hospitalized. Medical costs were incurred at a decreasing rate, from $2,428 in the first six weeks to $648 in the last six weeks. Mean total medical costs across all patients over the year were $8,930, including $5,328 in outpatient costs. Total costs were positively associated with baseline Charlson comorbidity score (P < 0.01). Outpatient costs were positively associated with baseline Charlson comorbidity score (P = 0.03) and a bodily pain burden summary score (P < 0.01). Mean patient cost-sharing summed to $1,342 and time costs summed to $1,346.

CONCLUSIONS

Costs in the ninety days and year after TKA can be substantial for both healthcare payers and patients. These costs should be considered as payers continue to explore alternative payment models.

Refining risk adjustment for bundled payment models in cervical fusions-an analysis of Medicare beneficiaries

BACKGROUND CONTEXT

The current Bundled Payment for Care Improvement model relies on the use of "Diagnosis Related Groups" (DRGs) to risk-adjust reimbursements associated with a 90-day episode of care. Three distinct DRG groups exist for defining payments associated with cervical fusions: (1) DRG-471 (cervical fusions with major comorbidity/complications), (2) DRG-472 (with comorbidity/complications), and (3) DRG-473 (without major comorbidity/complications). However, this DRG system may not be entirely suitable in controlling the large amounts of cost variation seen among cervical fusions. For instance, these DRGs do not account for area/location of surgery (upper cervical vs. lower cervical), type of surgery (primary vs. revision), surgical approach (anterior vs. posterior), extent of fusion (1-3 level vs. >3 level), and cause/indication of surgery (fracture vs. degenerative pathology).

PURPOSE

To understand factors responsible for cost variation in a 90-day episode of care following cervical fusions.

STUDY DESIGN

Retrospective study of a 5% national sample of Medicare claims from 2008 to 2014 5% Standard Analytical Files (SAF5).

OUTCOME MEASURES

To calculate the independent marginal cost impact of various patient-level, geographic-level, and procedure-level characteristics on 90-day reimbursements for patients undergoing cervical fusions under DRG-471, DRG-472, and DRG-473.

METHODS

The 2008 to 2014 Medicare SAF5 was queried using DRG codes 471, 472, and 473 to identify patients receiving a cervical fusion. Patients undergoing noncervical fusions (thoracolumbar), surgery for deformity/malignancy, and/or combined anterior-posterior fusions were excluded. Patients with missing data and/or those who died within 90 days of the postoperative follow-up period were excluded. Multivariate linear regression modeling was performed to assess the independent marginal cost impact of DRG, gender, age, state, procedure-level factors (including cause/indication of surgery), and comorbidities on total 90-day reimbursement.

RESULTS

Following application of inclusion/exclusion criteria, a total of 12,419 cervical fusions were included. The average 90-day reimbursement for each DRG group was as follows: (1) DRG-471=$54,314±$32,643, (2) DRG-472=$28,535±$17,271, and (3) DRG-473=$18,492±$10,706. The risk-adjusted 90-day reimbursement of a nongeriatric (age <65) female, with no major comorbidities, undergoing a primary 1- to 3-level anterior cervical fusion for degenerative cervical spine disease was $14,924±$753. Male gender (+$922) and age 70 to 84 (+$1,007 to +$2,431) was associated with significant marginal increases in 90-day reimbursements. Undergoing upper cervical surgery (-$1,678) had a negative marginal cost impact. Among other procedure-level factors, posterior approach (+$3,164), >3 level fusion (+$2,561), interbody (+$667), use of intra-operative neuromonitoring (+$1,018), concurrent decompression/laminectomy (+$1,657), and undergoing fusion for cervical fracture (+$3,530) were associated higher 90-day reimbursements. Severe individual comorbidities were associated with higher 90-day reimbursements, with malnutrition (+$15,536), CVA/stroke (+$6,982), drug abuse/dependence (+$5,059), hypercoagulopathy (+$5,436), and chronic kidney disease (+$4,925) having the highest marginal cost impacts. Significant state-level variation was noted, with Maryland (+$8,790), Alaska (+$6,410), Massachusetts (+$6,389), California (+$5,603), and New Mexico (+$5,530) having the highest reimbursements and Puerto Rico (-$7,492) and Iowa (-$3,393) having the lowest reimbursements, as compared with Michigan.

CONCLUSIONS

The current cervical fusion bundled payment model fails to employ a robust risk adjustment of prices resulting in the large amount of cost variation seen within 90-day reimbursements. Under the proposed DRG-based risk adjustment model, providers would be reimbursed the same amount for cervical fusions regardless of the surgical approach (posterior vs. anterior), the extent of fusion, use of adjunct procedures (decompressions), and cause/indication of surgery (fracture vs. degenerative pathology), despite each of these factors having different resource utilization and associated reimbursements. Our findings suggest that defining payments based on DRG codes only is an imperfect way of employing bundled payments for spinal fusions and will only end up creating major financial disincentives and barriers to access of care in the healthcare system.

Simulating Episode-Based Bundled Payments for Cranial Neurosurgical Procedures

BACKGROUND

Episode-based bundled payments were introduced by Medicare in 2013 as the Bundled Payments for Care Improvement (BPCI) in order to improve care coordination and cost efficiency. BPCI has not yet been applied to cranial neurosurgical procedures.

OBJECTIVE

To determine projected values of episode-based bundled payments when applied to common cranial neurosurgical procedures using retrospective data from a large database.

METHODS

We performed a large retrospective observational study using the MarketScan administrative database to project bundled payment payments for 4 groups of common cranial neurosurgical procedures.

RESULTS

We identified 15 276 procedures that met our inclusion criteria. We observed significant variability between groups, with 90-d bundle projected payments ranging from $ 58,200 for craniotomy for meningioma to $ 102,073 for craniotomy for malignant glioma. We also found significant variability in projected bundled payments within each class of operation. On average, payment for the index hospitalization accounted for 85% of projected payments for a 30-d bundle and 70.5% of projected payments for a 90-d bundle. Multivariable analysis showed that hospital readmission, discharge to postacute care facilities, venous-thrombo-embolism, medical comorbidities, adjuvant therapies, and payer status significantly contributed to projected cranial bundle payments.

CONCLUSION

For the first time, to our knowledge, we project the values of episode-based bundled payments for common vascular and tumor cranial operations. As previously identified in orthopedic procedures, there is significant variability in total bundle payments within each cranial procedure. Compared to spine and orthopedic procedures, postdischarge care significantly impacts total bundle payments in cranial neurosurgery.

Value-Based Care Has Not Resulted in Biased Patient Selection: Analysis of a Single Center's Experience in the Care for Joint Replacement Bundle

BACKGROUND

Bundled reimbursement models for total knee arthroplasty (TKA) by the Center for Medicare and Medicaid Services have resulted in an effort to decrease the cost of care. However, these models may incentivize bias in patient selection to avoid excess cost of care. We sought to determine the impact of the Comprehensive Care for Joint Replacement (CJR) model at a single center.

METHODS

This is a retrospective review of primary TKA patients from July 2015 to December 2017. Patients were stratified by whether or not their surgery was performed before or after implementation of the CJR bundle. Patient demographic data including age, sex, and body mass index were collected in addition to Elixhauser comorbidities and American Society of Anesthesiologists score. In-hospital outcomes were then examined including surgery duration, length of stay, discharge disposition, and direct cost of care.

RESULTS

A total of 1248 TKA patients (546 Medicare and 702 commercial insurance) were evaluated, with 27.0% undergoing surgery before the start of the bundle. Compared to patients following implementation of the bundle, there was no significant difference in age, gender, or body mass index. However, pre-CJR Medicare patients were more likely to have fewer Elixhauser comorbidities (P < .001), prolonged length of stay (P < .001), and greater discharges to inpatient facilities (P = .019). There was no significant difference in direct hospital costs or operative service time comparing pre-bundle and post-bundle patients.

CONCLUSION

Implementation of the bundled reimbursement model did not result in biased patient selection at our institution; importantly, it also did not result in decreased hospital costs despite apparent improvement in value-based outcome metrics. This should be taken into consideration as future adaptations to reimbursement are made by the Center for Medicare and Medicaid Services.

No Changes in Patient Selection and Value-Based Metrics for Total Hip Arthroplasty After Comprehensive Care for Joint Replacement Bundle Implementation at a Single Center

BACKGROUND

Alternative payment models for total hip arthroplasty (THA) were initiated by the Center for Medicare and Medicaid Services to decrease overall healthcare cost. The associated shift of financial risk to participating institutions may negatively influence patient selection to avoid high cost of care ("cherry picking," "lemon dropping"). This study evaluated the impact of the Comprehensive Care for Joint Replacement (CJR) model on patient selection, care delivery, and hospital costs at a single care center.

METHODS

Patients undergoing a primary THA from 2015-2017 were stratified by insurance type (Medicare and commercial insurance) and whether care was provided before (pre-CJR) or after (post-CJR) CJR bundle implementation. Patient age, gender, and body mass index, Elixhauser comorbidities and American Society of Anesthesiologists scores, were analyzed. Delivery of care variables including surgery duration, discharge disposition, length of stay, and direct hospital costs were compared pre- and post-CJR.

RESULTS

A total of 751 THA patients (273 Medicare and 478 commercial Insurance) were evaluated pre-CJR (29%) and post-CJR (71%). Patient demographics were similar (age, gender, BMI); however, commercially insured patients had less comorbidities pre-CJR (P = .033). Medicare patient post-CJR length of stay (P = .010) was reduced with a trend toward discharge to home (P = .019). Surgical time, operating room service time, 90-day readmissions and direct hospital costs were similar pre- and post-CJR.

CONCLUSION

There was no differential patient selection after CJR bundle implementation and value-based metrics (surgical time, operating room service time) were not affected. Patients were discharged sooner and more often to home. However, overall direct hospital expenses remained unchanged revealing that any cost savings were for insurance providers, not participating hospitals.

The cost of implanting a cemented versus cementless total knee arthroplasty

Aims

The aim of this study was to compare the actual cost of a cemented and cementless total knee arthroplasty (TKA) procedure.

Materials and Methods

The cost of operative time, implants, cement, and cementing accessories were included in the overall cost of the TKA procedure. Operative time was determined from a previously published study comparing cemented and cementless implants of the same design. The cost of operative time, implants, cement, and cementing accessories was determined from market and institutional data.

Results

Mean operative time for cemented TKA was 11.6 minutes longer for cemented TKA than cementless TKA (93.7 minutes (sd 16.7) vs 82.1 minutes (sd 16.6); p = 0.001). Using a conservative published standard of $36 per minute for operating theatre time cost, the total time cost was $418 higher for cementing TKA. The cost of cement and accessories ranged from $170 to $625. Overall, the calculated cost of cemented TKA is $588 to $1043, depending on technique. The general increased charge for cementless TKA implants over cemented TKA implants was $366.

Conclusion

The overall procedural cost of implanting a cementless TKA is less than implanting a cemented TKA. Cost alone should not be a barrier to using cementless TKA. Cite this article: Bone Joint J 2019;101-B(7 Supple C):61–63

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.

Modifying Patient Expectations Can Enhance Total Hip Arthroplasty Postoperative Satisfaction

BACKGROUND

A better understanding of patient expectations within the perioperative setting will enable clinicians to better tailor care to the needs of the total hip arthroplasty (THA) recipient. Such an approach will promote patient-centered decision-making and optimize recovery times while enhancing mandated hospital quality metrics. In the present study, we preoperatively and postoperatively surveyed THA candidates to elucidate the relationship between patient expectations and length of stay (LOS).

METHODS

This is a multi-institutional prospective study among THA candidates. Patients were surveyed regarding discharge planning 1 week preoperatively and postoperatively to capture perioperative patient expectations and correlate with inpatient LOS.

RESULTS

In total, 93 THAs performed by 6 high-volume orthopedic surgeons at 2 medical centers. Our results demonstrated that patients of male gender and commercial insurance had significantly (P < .05) shorter LOS. Shorter LOS patients demonstrated significantly higher levels of LOS acceptance ("very comfortable" rate in same-day discharge: 75.0% and next-day discharge: 63.8%; 2 days: 40.7%; 3+ days: 42.9%; P < .05) and a higher likelihood to participate in SDD programs. Postoperatively, patients with a shorter LOS had more acceptance to their LOS, albeit not statistically significant (P = .20).

CONCLUSION

Our results suggest that guiding patient expectations within the perioperative setting is an essential component for successful and timely discharge after THA. Having clear and transparent discussion with the surgical team regarding the perioperative course can improve a THA candidate's understanding and buy-in with the postoperative plan, regardless of LOS. Finally, inpatient LOS does not appear to affect patient satisfaction.

LEVEL OF EVIDENCE

Level II, prospective observational study.

‘Bundle busters’

Aims

The Bundled Payments for Care Improvement (BPCI) initiative has identified pathways for improving the value of care. However, patient-specific modifiable and non-modifiable risk factors may increase costs beyond the target payment. We sought to identify risk factors for exceeding our institution’s target payment, the so-called ‘bundle busters’.

Patients and Methods

Using our data warehouse and Centers for Medicare and Medicaid Services (CMS) data we identified all 412 patients who underwent total joint arthroplasty and qualified for our institution’s BPCI model, between July 2015 and May 2017. Episodes where CMS payments exceeded the target payment were considered ‘busters’ (n = 123). Risk ratios (RRs) were calculated using a modified Poisson regression analysis.

Results

An increased risk of exceeding the target payment was significantly associated with increasing age (adjusted RR 1.04, 95% confidence interval (CI) 1.01 to 1.06) and body mass index (adjusted RR 1.03, 95% CI 1.003 to 1.06). Eight comorbid risk factors were also identified (all p < 0.05), only two of which were considered to be potentially modifiable (diabetes with complications and preoperative anaemia). An American Society of Anesthesiologist physical status classification system (ASA) score ≥ 3 (adjusted RR 2.3, 95% CI 1.67 to 3.18) and Charlson Comorbidity Index (CCI) ≥ 3 (adjusted RR 1.94, 95% CI 1.45 to 2.60) were risk factors for bundle busting.

Conclusion

Non-modifiable preoperative risk factors can increase costs and exceed the target payment. Future bundled payment models should incorporate the stratification of risk. Cite this article: Bone Joint J 2019;101-B(7 Supple C):64–69

The Cost Effectiveness of Dilute Betadine Lavage for Infection Prophylaxis in Total Joint Arthroplasty

BACKGROUND

This article presents a break-even analysis for intraoperative Betadine lavage for the prevention of infection in total hip arthroplasty (THA) and total knee arthroplasty (TKA).

METHODS

Protocol costs, baseline infection rates after arthroplasty, and average revision costs were obtained from institutional records and the literature. The break-even analysis determined the absolute risk reduction (ARR) in infection rate required for cost effectiveness.

RESULTS

At our institutional price of $2.54, dilute (0.35%) Betadine lavage would be cost effective if initial infection rates of both TKA (1.10%) and THA (1.63%) have an ARR of 0.01%. At a hypothetical lowest cost of $0.50, the ARR is so low as to be immediately cost effective. At a hypothetical high price of $40.00, Betadine is cost effective with ARRs of 0.16% (TKA) and 0.13% (THA).

CONCLUSION

Intraoperative Betadine lavage, at typical institutional prices, can be highly cost effective in reducing infection after joint arthroplasty.

Should Medical Severity-Diagnosis Related Group Classification Be Utilized for Reimbursement? An Analysis of Elixhauser Comorbidities and Cost of Care

BACKGROUND

The Center for Medicare and Medicaid Services (CMS) classifies reimbursement for total hip arthroplasty (THA) and total knee arthroplasty (TKA) based on Medical Severity-Diagnosis Related Groups (MS-DRGs) 469 (with major complication/comorbidity) and 470 (without major complication/comorbidity). The validated Elixhauser comorbidity index includes 31 variables that may be associated with MS-DRG 469. However, we hypothesized that these comorbidities may not be the most predictive of increased cost of care.

METHODS

Elixhauser comorbidities were retrospectively examined for 1243 TKAs and 897 THAs from 2013 to 2017 at a single center. Comorbidities were investigated in univariable analysis and significant variables associated with MS-DRG 469, and cost of care was further investigated in a multivariable regression to determine which were most predictive of the increased complexity classification assigned by CMS vs true increased cost of care.

RESULTS

Thirty-nine patients (1.8%) were classified as MS-DRG 469. Univariable and multivariable logistic analysis revealed that coagulopathy, electrolyte disorders, neurodegenerative disorders, and psychosis were significantly associated with an increased complexity classification. These 4 comorbidities were also associated with increased cost of care; however, 13 additional comorbidities were also predictive of increased cost but not MS-DRG classification.

CONCLUSIONS

Patient comorbidities have been shown to increase complications and cost of care for arthroplasty patients. To date, however, the only risk adjustment provided has been the 469 DRG code. This study demonstrates little correlation to the current system with the most expensive diagnoses. Consequently, an expansion of the current risk adjustment system for THA and TKA provided by CMS appears greatly needed.