Ten-Year Trends and Independent Risk Factors for Unplanned Readmission Following Elective Total Joint Arthroplasty at a Large Urban Academic Hospital

Reliability and validity of the two-minute step test in patients with total knee arthroplasty

PURPOSE

To investigate the test-retest reliability and concurrent validity of 2MST for assessing the physical performance of patients with total knee arthroplasty (TKA).

MATERIALS AND METHODS

Fifty-one patients with TKA, aged more than 18 years, of both sexes, and underwent a primary TKA at least six months ago, were included in this study. The intraclass correlation coefficient (ICC) and 95% confidence interval (CI), standard error of measurement (SEM), and minimum detectable change at the 95% confidence level (MDC95) were used to determine the reliability of 2MST. In the validity, the correlations of the 2MST between the six-minute walk test (6MWT) and the two-minute walk test (2MWT) were assessed.

RESULTS

The reliability of 2MST was excellent (ICC = 0.97, SEM = 2.76, MDC95 = 7.6). There was a moderate correlation between 2MST and 6MWT (r = 0.586; p = 0.000), as well as between 2MST and 2MWT (r = 0.633; p = 0.000).

CONCLUSIONS

2MST proved to be a reliable and valid physical performance test in patients with TKA. 2MST can be used to evaluate the physical performance of TKA patients.ClinicalTrials.gov Identifier: NCT05064943.

Billing rules / global period affect postoperative follow-up practices following total hip arthroplasty

BACKGROUND

Total hip arthroplasty (THA) is a common procedure following which postoperative visits are important to optimize outcomes. The associated global billing period includes the 90 postoperative days (or approximately 13 weeks), during which professional billing is included with the surgery itself. The current study assessed clinical practice patterns relative to the global billing period.

METHODS

Using the PearlDiver M91Ortho dataset, the incidence and timing of Evaluation and Management (E&M) codes in the 26 weeks following THA were assessed. The follow-up visits within and beyond the global billing period, and those conducted by surgeons versus non-surgeon advanced practice providers (APPs) were determined.

RESULTS

77,843 THAs were identified. Follow-up visits peaked at postoperative weeks 3, 7, and 14. The greatest week-to-week variation in the number of follow-ups was from weeks 13 to 14 immediately following the global billing period (representing a greater than 4-fold increase in visits.) During the first 13 postop weeks, 73.8% of patients were seen by orthopedic surgeons (as opposed to APPs). In the following 13 weeks, a significantly greater percentage of visits were with surgeons (86.8%, p<0.0001).

CONCLUSIONS

Following the THA global billing period, there was marked increase in the number of follow-ups and transition to a greater percentage being performed by the surgeons. These results provide interesting insight into the potential impact of the billing structure on how practice is pursued.

Does Your Patient Need to Lose Weight? Weight Change Before and After Total Hip Arthroplasty Does Not Affect Health Care Utilization and Achievement of the Minimal Clinically Important Difference

BACKGROUND

Despite the potential negative impact of preoperative obesity on total hip arthroplasty (THA) outcomes, the association between preoperative and postoperative weight change and outcomes is much less understood. Therefore, this study aimed to determine the impact of preoperative and postoperative weight change and preoperative body mass index (BMI) on health care utilization, satisfaction, and achievement of minimal clinically important difference (MCID) for Hip Disability and Osteoarthritis Outcome Score Physical Function Short-Form (HOOS PS) and HOOS Pain.

METHODS

Patients who underwent primary elective unilateral THA between January 2016 and December 2019 were included (N = 2,868). Multivariable logistic regression assessed the association between BMI and preoperative and postoperative weight change on outcomes while controlling for demographic characteristics.

RESULTS

There was no association between preoperative weight change and prolonged length of stay (> 3 days), 90-day readmission, nonhome discharge, patient dissatisfaction at 1 year, or achievement of HOOS Pain or HOOS PS MCID. Postoperative weight loss was an independent risk factor for patient dissatisfaction at 1 year but was not associated with achievement of either HOOS Pain or HOOS PS MCID at 1-year postoperative. Preoperative obesity classes I to III were independent risk factors for nonhome discharge. Nevertheless, preoperative obesity class I and class II were associated with an increased probability of reaching HOOS Pain MCID. Preoperative BMI was not associated with an increased risk of patient dissatisfaction.

CONCLUSIONS

Preoperative weight change does not appear to influence health care utilization, satisfaction, or achievement of MCID in pain and function following THA. Postoperative weight loss may play a role as a risk factor for dissatisfaction following THA. Additionally, patients who had a higher baseline BMI may be more likely to see improvement in pain following THA. Therefore, when counseling obese patients for THA, surgeons must balance the risk of perioperative complications with the expectation of greater improvements in pain.

Hemiarthroplasty through SuperPATH versus hemiarthroplasty through conventional approaches in patients with femoral neck fractures: a systematic review and meta-analysis of randomized controlled trials

The aim was to conduct a systematic review of literature and meta-analysis of randomized controlled trials (RCTs) comparing short-term outcomes of bipolar hemiarthroplasty (HA) through SuperPATH and bipolar HA through conventional approaches (CAs) in patients with femoral neck fractures. The following PICO question was formulated: In human participants with femoral neck fractures, are the short-term outcomes of SuperPATH HA better than the short-term outcomes of CAs HA? The following databases were searched until 25 August 2023: PubMed, CNKI, CENTRAL of The Cochrane Library, Clinical trials, and Google Scholar. Quality assessment of the RCTs was performed, according to the Cochrane's Risk of Bias 2 tool and the recommendations of the GRADE system. Furthermore, we evaluated publication bias with funnel plots. Mean differences (MDs) with 95% confidence intervals (CIs) were calculated for continuous variables using the Hartung-Knapp-Sidik-Jonkman method and a random effects model. Nine RCTs with overall 762 patients were included in this meta-analysis. All 9 RCTs were rated with a moderate risk of bias. The quality of evidence of the outcome parameters was rated moderate to very low. The funnel plots were overall broadly symmetrical, possibly indicating low to moderate publication bias. SuperPATH had a longer operation time compared to CAs (MD = 21.79, 95% CI 12.57 to 31.02). SuperPATH decreased incision length (MD = - 4.50; 95% CI - 5.80 to - 3.20), intraoperative blood loss (MD = - 103.96, 95% CI - 150.27 to - 55.66), postoperative drainage volume (MD = - 137.30, 95% CI - 178.74 to - 95.86), time to mobilization (MD = - 3.86; 95% CI - 5.96 to - 1.76), pain VAS ≤ 1 week postoperatively (MD = - 1.81; 95% CI - 2.17 to - 1.45), and hospitalization time (MD = - 4.05; 95% CI - 4.96 to - 3.15). SuperPATH improved HHS ≤ 1 week postoperatively (MD = 11.10; 95% CI 1.65 to 20.54) and HHS 3 months postoperatively (MD = 6.33; 95% CI 3.97 to 8.69). There was no difference in pain VAS 1-3 months postoperatively (MD = - 0.08; 95% CI - 0.22 to 0.05) and HHS 6 months postoperatively (MD = 0.44; 95% CI - 0.11 to 1.00). This is the first meta-analysis comparing SuperPATH HA with CAs HA in patients with femoral neck fractures. SuperPATH HA was superior in the early short-term functional outcome (HHS) compared to CAs HA, reaching minimal clinically important differences. Furthermore, SuperPATH HA showed significantly better results in incision length, blood loss, time to mobilization, pain intensity (VAS), and hospitalization time than CAs HA.

Survivability of Titanium Implant Materials: In Vitro Simulated Inflammatory and Infectious Environment

Titanium-based implants utilized in total joint arthroplasties could restore primary musculoskeletal function to patients suffering from osteoarthritis and other conditions. Implants are susceptible to failure stemming from aseptic loosening and infection at the joint site, eventually requiring revision surgery. We hypothesized that there might be a feedback loop by which metal degradation particles and ions released from the implant decrease cell viability and increase immune response, thereby creating biochemical conditions that increase the corrosion rate and release more metal ions. This study focused on the synergistic process through cell viability assays and electrochemical tests. From the results, inflammatory conditions from ion release resulting in cell death would further increase the corrosion rate at the metal implant site. The synergistic interaction in the implant surroundings in which infectious conditions produce Ti ions that contribute to more infection, creating a potential cycle of accelerating corrosion.

Health and Socioeconomic Risk Factors for Unplanned Hospitalization Following Ambulatory Unicompartmental Knee Arthroplasty: Development of a Patient Selection Tool Using Machine Learning

BACKGROUND

Identifying ambulatory surgical candidates at risk for adverse surgical outcomes can optimize outcomes. The purpose of this study was to develop and internally validate a machine learning (ML) algorithm to predict contributors to unexpected hospitalizations after ambulatory unicompartmental knee arthroplasty (UKA).

METHODS

A total of 2,521 patients undergoing UKA from 2006 to 2018 were retrospectively evaluated. Patients admitted overnight postoperatively were identified as those who had a length of stay ≥ 1 day were analyzed with four individual ML models (ie, random forest, extreme gradient boosting, adaptive boosting, and elastic net penalized logistic regression). An additional model was produced as a weighted ensemble of the four individual algorithms. Area under the receiver operating characteristics (AUROC) compared predictive capacity of these models to conventional logistic regression techniques.

RESULTS

Of the 2,521 patients identified, 103 (4.1%) required at least one overnight stay following ambulatory UKA. The ML ensemble model achieved the best performance based on discrimination assessed via internal validation (AUROC = 87.3), outperforming individual models and conventional logistic regression (AUROC = 81.9-85.7). The variables determined most important by the ensemble model were cumulative time in the operating room, utilization of general anesthesia, increasing age, and patient residency in more urban areas. The model was integrated into a web-based open-access application.

CONCLUSION

The ensemble gradient-boosted ML algorithm demonstrated the highest performance in identifying factors contributing to unexpected hospitalizations in patients receiving UKA. This tool allows physicians and healthcare systems to identify patients at a higher risk of needing inpatient care after UKA.

Risk Factors and Predictors for Functional Outcome and Complication Rate in Total Hip Arthroplasty through Minimally Invasive and Conventional Approaches: A Systematic Review and Meta-Regression Analysis of 41 Randomized Controlled Trials

OBJECTIVE

To investigate and identify risk factors and predictors for the difference in functional outcome and complications between total hip arthroplasty (THA) through minimally invasive and conventional approaches, using a meta-regression analysis of randomized controlled trials (RCTs).

METHODS

A systematic review of the literature up to 31 July 2022 was performed. A meta-regression was conducted based on a random effects meta-analysis using the Hartung-Knapp-Sidik-Jonkman method.

RESULTS

A total of 41 RCTs with 3607 patients were found. The following predictors of HHS ≥ 6 months postoperatively were identified: patient age (predictor estimate = 0.14; p < 0.01), avascular necrosis of the femoral head (predictor estimate = -0.03; p = 0.04); incision length (predictor estimate = -0.82; p < 0.01). The following predictors of complication rate were identified: osteoarthritis (predictor estimate = 0.02; p = 0.02); femoral neck fracture (predictor estimate = -0.02; p = 0.02); SuperPATH (predictor estimate = -1.72; p < 0.01).

CONCLUSIONS

Patient age, avascular necrosis of the femoral head, and incision length were identified as predictors of the effect size of the HHS ≥ 6 months postoperatively; and osteoarthritis, femoral neck fracture, and SuperPATH as predictors of the effect size of the complication rate. Based on these findings, we recommend that more frequent use of minimally invasive THA in elderly patients should be considered.

LEVEL OF EVIDENCE I

a systematic review of all relevant randomized controlled trials. Registered in PROSPERO on 10 August 2022 (CRD42022350287).

SuperPATH-Current Status of Evidence and Further Investigations: A Scoping Review and Quality Assessment

BACKGROUND

SuperPATH is a novel minimally invasive technique for hip replacement that is gaining increasing attention. The aim of this review was to determine the nature, extent, and quality of current research evidence on SuperPATH and to identify areas for further investigations.

METHODS

A bibliometric search was conducted in PubMed up to 1 August 2023 using the search term "SuperPATH". Data extraction and quality assessment were performed for relevant articles.

RESULTS

The bibliometric search yielded 51 articles on SuperPATH, 9 of which were meta-analyses, 11 were randomized controlled trials (RCTs), 4 were prospective non-RCTs, 12 were retrospective comparative studies, 11 were case series, and 4 were other article types. Most articles were published between 2015 and 2023, with a steady increase in publications per year. The articles originated from 13 countries, of which China was the most productive (35%). The quality assessment of the meta-analyses showed that 22.2% were of moderate quality, 66.7% were of low quality, and 11.1% were of critically low quality. The quality assessment of the RCTs showed that 36.4% had a low risk of bias (RoB), 27.2% revealed some concerns, and 36.4% had a high RoB. All studies were evaluated for content and taken into account in the formulation of recommendations and conclusions.

CONCLUSIONS

The SuperPATH evidence varies from low to high quality. There is a steady increase in SuperPATH publications in the English-language literature and an uneven distribution of the article origins, with most articles coming from China. Consistent terminology should be used in the future, referring to the surgical approach as the direct superior approach (DSA) and to the surgical technique as SuperPATH. This review provides further concrete suggestions for future investigations and recommendations to improve study quality.

Medicaid Patients Undergo Total Joint Arthroplasty at Lower-Volume Hospitals by Lower-Volume Surgeons and Have Poorer Outcomes

BACKGROUND

Medicaid insurance coverage among patients undergoing total hip arthroplasty (THA) or those undergoing total knee arthroplasty (TKA) has been associated with worse postoperative outcomes compared with patients without Medicaid. Surgeons and hospitals with lower annual total joint arthroplasty (TJA) volume have also been associated with worse outcomes. This study sought to characterize the associations between Medicaid insurance status, surgeon case volume, and hospital case volume and to assess the rates of postoperative complications compared with other payer types.

METHODS

The Premier Healthcare Database was queried for all adult patients who underwent primary TJA from 2016 to 2019. Patients were divided on the basis of their insurance status: Medicaid compared with non-Medicaid. The distribution of annual hospital and surgeon case volume was assessed for each cohort. Multivariable analyses were performed accounting for patient demographic characteristics, comorbidities, surgeon volume, and hospital volume to assess the 90-day risk of postoperative complications by insurance status.

RESULTS

Overall, 986,230 patients who underwent TJA were identified. Of these, 44,370 (4.5%) had Medicaid. Of the patients undergoing TJA, 46.4% of those with Medicaid were treated by surgeons performing ≤100 TJA cases annually compared with 34.3% of those without Medicaid. Furthermore, a higher percentage of patients with Medicaid underwent TJA at lower-volume hospitals performing ≤500 cases annually, 50.8% compared with 35.5% for patients without Medicaid. After accounting for differences among the 2 cohorts, patients with Medicaid remained at increased risk for postoperative deep vein thrombosis (adjusted odds ratio [OR], 1.16; p = 0.031), pulmonary embolism (adjusted OR, 1.39; p < 0.001), periprosthetic joint infection (adjusted OR, 1.35; p < 0.001), and 90-day readmission (adjusted OR, 1.25; p < 0.001).

CONCLUSIONS

Patients with Medicaid were more likely to undergo TJA performed by lower-volume surgeons at lower-volume hospitals and had higher rates of postoperative complications compared with patients without Medicaid. Future research should assess socioeconomic status, insurance, and postoperative outcomes in this vulnerable patient population seeking arthroplasty care.

LEVEL OF EVIDENCE

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

Hospital Readmissions After Total Joint Arthroplasty: An Updated Analysis and Implications for Value-Based Care

BACKGROUND

While risk factors have been published for readmissions following primary total joint arthroplasty, little is known about the etiology of those costly adverse events. In this study, we sought to identify the reasons for 30-day readmission following primary total joint arthroplasty in a contemporary national patient sample.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program was queried to identify 367,199 patients who underwent primary total knee (TKA) or hip arthroplasty (THA) between 2011 and 2018. The primary outcomes were the annual rates of 30-day readmissions and the causes of those readmissions.

RESULTS

The 30-day readmission rate trended downward from 4.5% in 2011 to 3.3% in 2018. Medical complications accounted for 52.6% and 38.5% of readmissions following TKA and THA, respectively. Diseases of the circulatory system, abnormal laboratory values, and diseases of the digestive system were the leading causes of medical readmissions. Surgical complications accounted for 37.7% and 50.7% of readmissions following TKA and THA, respectively. Surgical site infections/wound disruption and venous thromboembolism were the leading two causes of surgical readmissions for THA and TKA. Prosthetic complications-namely dislocations and periprosthetic fractures-were the third leading cause of surgical readmissions for THA. For TKA, musculoskeletal conditions-namely pain and hematoma-were the third leading cause of surgical readmissions.

CONCLUSION

Medical complications accounted for half of all TKA readmissions and more than a third of THA readmissions. This could penalize institutions participating in value-based payment programs or dissuade others who are considering participation in such programs.

Hospital Revenue, Cost, and Contribution Margin in Inpatient Versus Outpatient Primary Total Joint Arthroplasty

BACKGROUND

Removal of primary total knee arthroplasty (TKA) and primary total hip arthroplasty (THA) from the inpatient-only list has financial implications for both patients and institutions. The aim of this study was to evaluate and compare financial parameters between patients designated for inpatient versus outpatient total joint arthroplasty.

METHODS

We reviewed all patients who underwent TKA or THA after these procedures were removed from the inpatient-only list. Patients were statistical significance into cohorts based on inpatient or outpatient status, procedure type, and insurance type. This included 5,284 patients, of which 4,279 were designated inpatient while 1,005 were designated outpatient. Patient demographic, perioperative, and financial data including per patient revenues, total and direct costs, and contribution margins (CMs) were collected. Data were compared using t-tests and Chi-squared tests.

RESULTS

Among Medicare patients receiving THA, CM was 89.1% lower for the inpatient cohort when compared to outpatient (P < .001), although there was no statistical significance difference between cohorts for TKA (P = .501). Among patients covered by Medicaid or Government-managed plans, CM was 120.8% higher for inpatients receiving THA (P < .001) when compared to outpatients and 136.3% higher for inpatients receiving TKA (P < .001).

CONCLUSION

Our analyses showed that recent costs associated with inpatient stay inconsistently match or outpace additional revenue, causing CM to vary drastically depending on insurance and procedure type. For Medicare patients receiving THA, inpatient surgery is financially disincentivized leaving this vulnerable patient population at a risk of losing access to care.

LEVEL III EVIDENCE

Retrospective Cohort Study.

The effect of different insert design congruencies on the kinematics of a mobile bearing TKA: A cadaveric study

Introduction

Total knee arthroplasty has proved to be a safe, effective and reproducible surgical treatment for patients with serious/advanced degenerative joint disease of the knee, but the optimal results after these implants can be achieved only if the joint kinematics and kinetics are carefully respected and not significantly altered after the replacement. In order to enhance the capability of matching the healthy configuration, therefore, different prosthesis models in terms of constraints and designs are available for the surgeons to choose among. As an example of this variety, mobile bearing models allow the surgeon to choose among different insert designs in terms of geometry and relative biomechanical approaches, with the relative performances depending on which one is adopted.This article aims to analyse the effect of different levels of congruency of mobile bearing inserts through an experimental activity performed on an ultra-congruent insert design, also referred as deep-dished.

Methods

The experimental activity followed the same protocol used in a previous study focused on the effect of symmetricity/asymmetricity (in order to allow a comparison among the results obtained), i.e. it analysed passive squat on 5 cadaveric knee specimens; internal-external rotations of femur and tibial insert respect to the tibia tray were thus measured via a motion capture system in order to compare the insert-femur relative rotation among the different congruency configurations.

Results

The overall knee kinematic (in terms of flexion-extension and internal-external rotation ranges of motion) with an ultra-congruent insert did not differ from the ones found for the other inserts; the insert-femur rotation values, instead, returned to be between the ones obtained with the other two inserts.

Conclusion

In terms of adaptability to tibio-femoral rotation, therefore, this insert represents a valid option for the surgeon seeking for an intermediate solution among the opposed approaches of the other two.

Physical and Mental Demand During Total Hip Arthroplasty

This study compared differences in (1) task duration; (2) biometric parameters (ie, caloric energy expenditure, heart rate); and (3) subjective measures of mental as well as physical demand of robotic-assisted total hip arthroplasty (THA) and manual THA. A total of 12 THAs were performed on 6 cadaveric specimens by two surgeons using a wearable technology to track biometric parameters and taking a questionnaire to compare the physical and mental demands. The results of our study suggest that as compared with manual techniques, robotic assistance for THA may reduce mental and physical fatigue.

Spinal Compared with General Anesthesia in Contemporary Primary Total Hip Arthroplasties

BACKGROUND

The specific advantages of spinal anesthesia compared with general anesthesia for primary total hip arthroplasty (THA) remains unknown. Therefore, this study aimed to investigate the pain control, length of stay, and postoperative outcomes associated with spinal anesthesia compared with general anesthesia in a large cohort of primary THAs from a single, high-volume academic institution.

METHODS

We retrospectively identified 13,730 primary THAs (11,319 patients) from 2001 to 2016 using our total joint registry. Of these cases, 58% had general anesthesia and 42% had spinal anesthesia. The demographic characteristics were similar between groups, with mean age of 64 years, 51% female, and mean body mass index (BMI) of 31 kg/m 2 . Data were analyzed using an inverse probability of treatment weighted model based on a propensity score that accounted for numerous patient and operative factors. The mean follow-up was 6 years.

RESULTS

Patients treated with spinal anesthesia had lower Numeric Pain Rating Scale (NPRS) scores (p < 0.001) and required fewer postoperative oral morphine equivalents (OMEs) at all time points evaluated (p < 0.001). Patients treated with spinal anesthesia also had shorter hospital length of stay (p = 0.02), fewer altered mental status events (odds ratio [OR], 0.7; p = 0.02), and fewer intensive care unit (ICU) admissions (OR, 0.7; p = 0.01). There was no difference in the incidence of deep vein thrombosis (p = 0.8), pulmonary embolism (p = 0.4), 30-day readmissions (p = 0.17), 90-day readmissions (p = 0.18), all-cause revisions (p = 0.17), or all-cause reoperations (p = 0.14).

CONCLUSIONS

In this large, single-institution study, we found that spinal anesthesia was associated with reduced pain scores and OME use postoperatively. Furthermore, spinal anesthesia resulted in fewer altered mental status events and ICU admissions. These data favor the use of spinal anesthesia in primary THAs.

LEVEL OF EVIDENCE

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

Incidence, patterns and risk factors for readmission following knee arthroplasty in China: A national retrospective cohort study

BACKGROUND

Limited data exist on readmission following knee arthroplasty (KA) in countries without well-established referral or extended care systems. This study aimed to investigate the incidence, patterns and risk factors for readmission following KA in China.

MATERIAL AND METHODS

In this national retrospective cohort study, we reviewed 167,265 primary KAs registered in the Hospital Quality Monitoring System in China between 2013 and 2018. Readmissions after KA within 30 and 90 days were evaluated. The causes for readmission were identified and classified as surgical or medical. The potential risk factors of readmission were assessed using multivariable logistic regression.

RESULTS

4017 (2.4%) patients readmitted within 30 days, and 7258 (4.3%) patients readmitted within 90 days. The readmission rate exhibited a downward trend during the period from 2013 to 2018 (2.7%-2.3% for 30-day readmission; 4.5%-4.2% for 90-day readmission). Surgical causes contributed to 54.3% readmissions within 30 days and 47.3% readmissions within 90 days. Wound infection/complication, joint pain, and thromboembolism were the most frequently reported reasons for surgical readmission. Older age, male sex, single marital status, non-osteoarthritis indication, a high comorbidity index, non-provincial hospitals, low hospital volume, and longer length of stay were associated with an increased risk of readmission. The geographic regions of hospitals contributed greatly to the variety of readmissions.

CONCLUSION

The readmission rate following KA decreased from 2013 to 2018. Surgery-related causes, especially wound infection/complication and pain, accounted for a large proportion. Both patient and hospital factors were associated with readmissions. Improved primary care and targeted measures are needed to help further prevent readmissions and optimize resource utilization.

Bicompartmental, medial and patellofemoral knee replacement might be able to maintain unloaded knee kinematics

INTRODUCTION

Unicompartmental knee arthroplasty (UKA) and total knee arthroplasty (TKA) are standard procedures for treating knee joint arthritis. Neither UKA nor TKA seems to be optimally suited for patients with bicompartmental osteoarthritis that affects only the medial and patellofemoral compartments. A bicompartmental knee arthroplasty (BKA) was designed for this patient group. This study aimed to compare the effectiveness of a BKA and TKA in restoring the kinematics of the knee joint.

MATERIALS AND METHODS

In this in vitro study, three types of knee arthroplasties (BKA, posterior cruciate ligament-retaining, and posterior cruciate ligament-resecting TKA) were biomechanically tested in six freshly frozen human cadaveric specimens. Complete three-dimensional kinematics was analyzed for each knee arthroplasty during both passive and loaded conditions in a validated knee kinematics rig. Infrared motion capture cameras and retroreflective markers were used for recording data.

RESULTS

No significant differences could be found between the three types of arthroplasties. However, similar kinematic changes between BKA and a native knee joint were documented under passive conditions. However, in a weight-bearing mode, a significant decrease in femoral rotation during the range of motion was found in arthroplasties compared to the native knee, probably caused by contraction of the quadriceps femoris muscle, which leads to a decrease in the anterior translation of the tibia.

CONCLUSIONS

Kinematics similar to that of the natural knee can be achieved by BKA under passive conditions. However, no functional advantage of BKA over TKA was detected, which suggests that natural knee kinematics cannot be fully imitated by an arthroplasty yet. Further prospective studies are required to determine the anatomic and design factors that might affect the physiologic kinematics.

Length of Stay Increases 90-day Readmission Rates in Patients Undergoing Primary Total Joint Arthroplasty

Postoperative length of stay (LOS) of 1 day compared with that of 2 to 4 days after primary total knee arthroplasty (TKA) or total hip arthroplasty (THA) and 90-day readmissions.

Clinical Outcomes, Health Care Costs and Prognostic Factors for Total Knee Arthroplasty: A Multilevel Analysis of a National Cohort Study Using Administrative Claims Data

Total knee arthroplasty (TKA) is one of the most frequent orthopaedic surgeries. The purpose of this study was to determine the 30-day postoperative mortality rate, total episode-of-care costs, and prognostic factors associated with these outcomes, for adult patients who underwent TKA in Colombia's contributory health care system. A retrospective cohort study of all adult patients enrolled in Colombia's contributory health system, who underwent TKA between January 1, 2012 and November 30, 2015 was performed. Thirty-day postoperative mortality rates, 30-day ICU admissions rates, 30-day hospital readmission rates, 1-year arthroplasty revision rates, and total episode-of-care costs were estimated. Multilevel, generalized linear models were generated, to determine the prognostic factors associated with outcomes presented. A total of 12,453 patients were included. The 30-day mortality rate was 0.13 per 100 surgeries and the ICU admissions rate at 30 days postoperative was 4.44 per 100 surgeries. The 30-day hospital readmission rate was 4.28 per 100 surgeries and the 1-year arthroplasty revision rate was 1.22 per 100 surgeries. The prognostic factors associated with mortality were age, Charlson Index, and type of insurer. The prognostic factors associated with hospital readmission were age category, Charlson Index, and geographic region; younger age and higher Charlson Index were found to be associated with a higher 1-year arthroplasty revision rate. The median of total episode-of-care costs was USD$ 6,190.07 (interquartile range: 2,299-7,282). The multivariate model found that age, the Charlson Index, the Atlantic region, and type of insurer were associated with the costs incurred by the health system. For patients undergoing TKA in Colombia, age, the Charlson Index, insurers, and geographic region are associated with mortality, ICU admissions, 30-day hospital readmissions, 1-year arthroplasty revisions, and total costs incurred by the health system.

Pre-Operative Predictors for Discharge to Post-Acute Care Facilities After Total Knee Arthroplasty

BACKGROUND

Joint replacement surgery is in increasing demand and is the most common inpatient surgery for Medicare beneficiaries. The venue for post-operative rehabilitation, including early outpatient therapy after surgery, influences recovery and quality of life. As part of a comprehensive total joint program at Kaiser Permanente Colorado, we developed and validated a predictive model to anticipate and plan the disposition for rehabilitation of our patients after total knee arthroplasty (TKA).

METHODS

We analyzed data for TKA patients who completed a pre-operative Total Knee Risk Assessment in 2017 (the model development cohort) or during the first 6 months of 2018 (the model validation cohort). The Total Knee Risk Assessment, which is used to guide disposition for rehabilitation, included questions in mobility, social, and environment domains. Multivariable logistic regression was used to predict discharge to post-acute care facilities (PACFs) (ie, skilled nursing facilities or acute rehabilitation centers).

RESULTS

Data for a total of 1481 and 631 patients who underwent TKA were analyzed in the development and validation cohorts, respectively. Ninety-three patients (6.3%) in the development cohort and 22 patients (3.5%) in the validation cohort were discharged to PACFs. Eight risk factors for discharge to PACFs were included in the final multivariable model. Patients with a diagnosis of neurological disorder and with a mobility/balance issue had the greatest chance of discharge to PACFs.

CONCLUSION

This validated predictive model for discharge disposition following TKA may be used as a tool in shared decision-making and discharge planning for patients undergoing TKA.

Effects of total knee arthroplasty for primary knee osteoarthritis on postural balance: A systematic review

BACKGROUND

Knee osteoarthritis is often related to physical function impairment. Although total knee arthroplasty is considered effective for advanced cases of knee osteoarthritis, its effects on postural balance is a topic of debate.

RESEARCH QUESTION

What are the effects of total knee arthroplasty for primary knee osteoarthritis on postural balance compared to preoperative status and/or to healthy controls?.

METHODS

Longitudinal studies (with more than 1-month follow-up) assessing postural balance measures (either clinical-based such as balance scales or laboratory-based such as postural sway) were considered eligible and selected in a 2-phase process. Six main electronic databases were searched, complemented by 3 grey literature sources. The risk of bias was evaluated using the Joanna Briggs Institute Critical Appraisal Tools.

RESULTS

A total of 19 studies were included for qualitative synthesis, of which 14 had low and 5 had a moderate risk of bias. The follow-up period ranged from 1-24 months. Most studies (n = 11) presented comparisons to preoperative status only. From these, 7 studies reported relevant improvements in postural balance, 2 reported partial improvements, and 2 no improvements. The remaining studies (n = 8) presented comparisons to healthy controls and, although improvements following total knee arthroplasty were consistently observed, only one study reported postural balance measures comparable to that of controls.

CONCLUSIONS

The majority of studies reported relevant improvements (especially in clinical-based measures) compared to preoperative evaluations, although inconsistencies were found possibly due to variability in studies' populations, assessment tools, and follow-up times. Despite this, persistent deficits in postural balance were commonly observed when compared to healthy controls.

SIGNIFICANCE

This evidence synthesis could better inform clinicians and researchers about the therapeutic effects and limitations of total knee arthroplasty concerning postural balance. Standardization of assessment tools is recommended to strengthen the certainty of cumulative evidence.

From Winners to Losers: The Methodology of Bundled Payments for Care Improvement Advanced Disincentivizes Participation in Bundled Payment Programs

BACKGROUND

The Bundled Payments for Care Improvement (BPCI) initiative improved quality and reduced costs following total hip (THA) and knee arthroplasty (TKA). In October 2018, the BPCI-Advanced program was implemented. The purpose of this study is to compare the quality metrics and performance between our institution's participation in the BPCI program with the BPCI-Advanced initiative.

METHODS

We reviewed a consecutive series of Medicare primary THA and TKA patients. Demographics, medical comorbidities, discharge disposition, readmission, and complication rates were compared between BPCI and BPCI-Advanced groups. Medicare claims data were used to compare episode-of-care costs, target price, and margin per patient between the cohorts.

RESULTS

Compared to BPCI patients (n = 9222), BPCI-Advanced patients (n = 2430) had lower rates of readmission (5.8% vs 3.8%, P = .001) and higher rate of discharge to home (72% vs 78%, P < .001) with similar rates of complications (4% vs 4%, P = .216). Medical comorbidities were similar between groups. BPCI-Advanced patients had higher episode-of-care costs ($22,044 vs $18,440, P < .001) and a higher mean target price ($21,154 vs $20,277, P < .001). BPCI-Advanced patients had a reduced per-patient margin compared to BPCI ($890 loss vs $1459 gain, P < .001), resulting in a $2,138,670 loss in the first three-quarters of program participation.

CONCLUSION

Despite marked improvements in quality metrics, our institution suffered a substantial loss through BPCI-Advanced secondary to methodological changes within the program, such as the exclusion of outpatient TKAs, facility-specific target pricing, and the elimination of different risk tracks for institutions. Medicare should consider adjustments to this program to keep surgeons participating in alternative payment models.

Single-Stage Bilateral Total Hip Arthroplasty in an Ambulatory Surgical Center: A Report of Three Cases

In recent years, there has been increased interest in transitioning total joint arthroplasty procedures from inpatient settings to ambulatory surgical centers to decrease costs and eliminate the need for hospital stays. In addition, simultaneous bilateral total hip arthroplasty (THA) has been found to be favorable in certain patient populations when compared with staged bilateral THA. In this study, we report the results of a series of three patients who underwent single-stage bilateral THA in a free-standing ambulatory surgical center with excellent short-term outcomes and no 90-day complications.

The local concentration of Ca2+ correlates with BMP7 expression and osseointegration in patients with total hip arthroplasty

BACKGROUND

A successful osseointegration of total hip arthroplasty (THA) relies on the interplay of implant surface and bone marrow microenvironment. This study was undertaken to investigate the impact of perioperative biochemical molecules (Ca²⁺, Mg²⁺, Zn²⁺, VD, PTH) on the bone marrow osteogenetic factors (BMP2, BMP7, Stro-1⁺ cells) in the metaphyseal region of the femoral head, and further on the bone mineral density (BMD) of Gruen R3.

METHODS

Bone marrow aspirates were obtained from the discarded metaphysis region of the femoral head in 51 patients with THA. Flow cytometry was used to measure the Stro-1⁺ expressing cells. ELISA was used to measure the concentrations of bone morphologic proteins (BMP2 and BMP7) and the content of TRACP5b in serum. TRAP staining was used to detect the osteoclast activity in the hip joint. The perioperative concentrations of the biochemical molecules above were measured by radioimmunoassay. The BMD of Gruen zone R3 was examined at 6 months after THA, using dual-energy X-ray absorptiometry (DEXA).

RESULTS

Our data demonstrated that the concentration of Ca²⁺ was positively correlated with BMP7 expression, and with the postoperative BMD of Gruen zone R3. However, the concentration of Mg²⁺ had little impact on the R3 BMD, although it was negatively correlated with the expression of BMP7. Osteoclast activity in hip joint tissue of patients with femoral neck fractures was increased. Compared with the patients before THA, the levels of TRACP5b in serum of patients after THA were decreased. The data also suggested that the other biochemical molecules, such as Zn²⁺, VD, and PTH, were not significantly correlated with any bone marrow osteogenetic factors (BMP2, BMP7, Stro-1⁺ cells). The postoperative R3 BMD of patients of different gender and age had no significant difference.

CONCLUSIONS

These results indicate the local concentration of Ca²⁺ may be an indicator for the prognosis of THA patients.

The Removal of Total Hip and Total Knee Arthroplasty From the Inpatient-Only List Increases the Administrative Burden of Surgeons and Continues to Cause Confusion

BACKGROUND

Several studies have shown that the removal of total knee arthroplasty (TKA) from the Centers for Medicare and Medicaid Services (CMS) inpatient-only (IPO) list has caused confusion among surgeons, hospitals, and patients. The purpose of this study is to determine whether similar confusion was present after CMS recently removed total hip arthroplasty (THA) from the IPO list.

METHODS

We surveyed the American Association of Hip and Knee Surgeons membership via an online web-based questionnaire in February 2020. The 12-question form asked about practice type and the impact that having both THA and TKA removed from the IPO list has had on each surgeon's practice. Responses were tabulated and descriptive statistics of each question reported.

RESULTS

Of the 2847 American Association of Hip and Knee Surgeons members surveyed, 419 responded (14.7% response rate). Three hundred forty-one surgeons (81%) stated that changes to IPO status have increased their practice's administrative burden. Fifty-four percent of surgeons reported that they have needed to obtain preauthorization or appeal a denial of preauthorization for an inpatient total joint arthroplasty at least monthly, while 257 surgeons (61%) have had patients contact their office regarding an unexpected copayment. Despite the commitment of CMS to waiving certain audits for 2 years, 43 respondents (10%) stated they had undergone an audit regarding a patient's inpatient status.

CONCLUSION

The removal of THA and TKA from the IPO list continues to be an administrative burden for arthroplasty surgeons and a source of confusion among patients. CMS should provide additional guidance to address surgeons' concerns about preauthorization for inpatient stays, unexpected patient copayments, and CMS audits.

Substantial Preoperative Work Is Unaccounted for in Total Hip and Knee Arthroplasty

BACKGROUND

The Centers for Medicare and Medicaid Services has recently designated the codes for total hip and knee arthroplasty as misvalued and has asked the Relative Value Scale Update Committee (RUC) to review the work required to perform these procedures. Although other studies have reported time spent on perioperative and postoperative care, time spent on coordinating and performing preoperative care is not included in current RUC methodology and has yet to be addressed in literature.

METHODS

We prospectively tracked a consecutive series of 438 primary total hip arthroplasty and total knee arthroplasty patients by one of the 5 surgeons over a 3-month period. Each clinical staff member tracked the amount of time to perform each preoperative care task from the last clinic visit until day of surgery. Data were analyzed separately between providers and ancillary medical staff.

RESULTS

Although the current RUC review includes 40 minutes of preservice time on the day of surgery, surgeons spent an average of an additional 43.2 minutes while physician assistants and nurse practitioners spent an additional 97.9 minutes per patient on preoperative care prior to that time. Ancillary medical staff spent a mean of 110.2 minutes per patient. The most common tasks include preoperative phone calls, templating and surgical planning, and preoperative patient education classes.

CONCLUSION

Surgeons and advanced practice providers spend nearly 2 hours per arthroplasty patient on preoperative care not accounted for in current RUC methodology. As readmissions, hospital stay, and complication rates continue to decline, Centers for Medicare and Medicaid Services should consider the substantial work required during the preoperative phase to allow for these improved outcomes.

Temporal Trends and Predictors of Thirty-Day Readmissions and Emergency Department Visits Following Total Knee Arthroplasty in Ontario Between 2003 and 2016

BACKGROUND

Total knee arthroplasty (TKA) is the second most common surgery performed in Canada. Understanding and improving quality metrics associated with such high-volume procedures is of utmost importance to maximize value within the healthcare system, which is a balance between cost and quality. Although rates and predictors of hospital readmission and emergency department (ED) visits following TKA have previously been described in privatized healthcare settings, few studies have evaluated trends in length of stay (LOS), hospital readmissions, and ED visits following TKA in a universal single-payer system.

METHODS

Using data from a provincially held and validated registry, the Institute for Clinical and Evaluative Sciences, we undertook a review of all 205,152 TKAs performed in the province of Ontario, Canada, between 2003 and 2016. We determined temporal trends in utilization, LOS, readmissions, and ED visits and evaluated patient and provider predictors of hospital readmissions and ED visits using multivariate logistic regression modeling. We also grouped and described the most common reasons for readmission and ED visits based on the available International Classification of Diseases, Ninth Revision and Tenth Revision coding information.

RESULTS

LOS decreased significantly over the study period (P < .0001), from a median of 5 days (10th percentile 3 days, 90th percentile 8 days) in 2003 to a median of 3 days (10th percentile 2 days, 90th percentile 4 days) in 2016. All-cause 30-day readmissions did not change significantly over the study period, but the rate of ED visits increased significantly over time. Predictors of 30-day readmission following TKA included older age, male gender, lower income quartile, not having a postoperative visit with a primary care physician (PCP), increased comorbidities, longer LOS, urgent or revision surgery, admission to a teaching hospital, and discharge to an inpatient rehabilitation facility. Variables that predicted increased odds of an ED visit included older age, male gender, lower income quartile, not having a postop visit with a PCP, increasing comorbidities, year of surgery, longer LOS, and revision surgery. Admission to a teaching hospital and discharge to an inpatient rehabilitation facility showed a trend toward increased odds of an ED visit.

CONCLUSIONS

We identified a significant increase in ED visits following TKA in Ontario between 2003 and 2016, with no corresponding increase in hospital readmissions despite a significant temporal trend toward shorter LOS. Predictors of ED visits and readmissions were similar, including male gender, lower income, higher comorbidities, and lacking a PCP visit postoperatively. Increased rates of ED visits following TKA in Ontario represent a quality problem, as they are associated with increased cost to the public healthcare system without any substantial benefit. Interventions aimed at redirecting patients from the ED for minor postoperative concerns should be investigated, as this is likely to improve care by reducing costs, improving efficiency, and enhancing patient experience.

Patient-related risk factors for unplanned 30-day readmission following total knee arthroplasty: a narrative literature review

Osteoarthritis is a debilitating condition as well as a growing global health problem, and total knee arthroplasty (TKA) is an effective treatment for advanced disease. Unplanned 30-day hospital readmission is an indicator of complications, which is a significant financial burden on healthcare systems. We reviewed the literature to better understand the patient-related factors associated with unplanned 30-day readmission following TKA. MEDLINE and EMBASE were searched for studies reporting on patient-related risk factors for unplanned 30-day readmission following primary or revision TKA for any indication. The impact of specific medical comorbidities on increasing the risk of 30-day readmission following TKA is quite well established. The following comorbidities are strongly associated with readmission: bleeding disorder, diabetes, chronic kidney disease and dialysis, chronic immunosuppressant use and history of cancer. Other significant comorbidities include: dementia; depression; haematological (coagulopathy and anaemia), cardiovascular (atrial fibrillation, cardiovascular disease, coronary artery disease and congestive heart failure), respiratory (chronic obstructive pulmonary disease) and liver diseases; and cerebrovascular accident/transient ischaemic attack (but only in revision TKA patients). The influence of variation in sex, age and body mass index each demonstrate a more complex pattern. A systematic review and meta-analysis is required to quantify the impact of the various patient-related factors on 30-day readmission following TKA. Clinicians can use this information in preoperative decision-making.

Patient-related risk factors for unplanned 30-day readmission following total knee arthroplasty: a protocol for a systematic review and meta-analysis

BACKGROUND

Osteoarthritis is a debilitating condition as well as a growing global health problem, and total knee arthroplasty is an effective treatment for advanced stages of disease. Unplanned 30-day hospital readmission is an indicator of complications, which is a significant financial burden on healthcare systems. The objective is to perform a systematic review of patient-related factors associated with unplanned 30-day readmission following total knee arthroplasty. This information will inform future strategies to improve health outcomes after knee arthroplasty surgery.

METHODS

MEDLINE and EMBASE will be systematically searched using a comprehensive search strategy. Studies of higher quality than case series will be included, in order to optimise the quality of the findings of this review. We will include studies reporting on patient-related risk factors for unplanned 30-day readmission following primary or revision total knee arthroplasty for any indication. Case series will be excluded, as will studies reporting exclusively on intraoperative, clinician, hospital, and health system risk factors. The reference lists of selected papers will then be screened for any additional literature. Two reviewers will independently apply stringent eligibility criteria to titles, abstracts, and full texts of studies identified in the literature search. They will then extract data from the final list of selected papers according to an agreed-upon taxonomy and vocabulary of the data to be extracted. Assessment of risk of bias and quality of evidence will then take place. Finally, the effect size of each identified risk factor will be determined; meta-analysis will be performed where adequate data is available.

DISCUSSION

The findings of this review and subsequent meta-analysis will aid clinicians as they seek to understand the risk factors for 30-day readmission following total knee arthroplasty. Clinicians and patients will be able to use this information to align expectations of the postoperative course, which will enhance the recovery process, and aid in the development of strategies to mitigate identified risks. Another purpose of this review is to assist policy-makers in developing quality indicators for care and provide insights into the drivers of health costs.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42019118154.

A Weighted Index of Elixhauser Comorbidities for Predicting 90-day Readmission After Total Joint Arthroplasty

BACKGROUND

Evolving reimbursement models increasingly compel hospitals to assume costs for 90-day readmission after total joint arthroplasty. Although risk assessment tools exist, none currently reach the predictive performance required to accurately identify high-risk patients and modulate perioperative care accordingly. Although unlikely to perform adequately alone, the Elixhauser index is a set of 31 variables that may lend value in a broader model predicting 90-day readmission.

METHODS

Elixhauser comorbidities were examined in 10,022 primary unilateral total joint replacements, of which 4535 were hip replacements and 5487 were knee replacements, all performed between June 2013 and January 2018 at a single tertiary referral center. Data were extracted from electronic medical records using structured query language. After randomizing to derivation (80%) and validation (20%) subgroups, predictive models for 90-day readmission were generated and transformed into a system of weights based on each parameter's relative performance.

RESULTS

We observed 497 90-day readmissions (5.0%) during the study period, which demonstrated independent associations with 14 of the 31 Elixhauser comorbidity groups. A score created from the sum of each patient's weighted comorbidities did not lose substantial predictive discrimination (area under the curve: 0.653) compared to a comprehensive multivariable model containing all 31 unweighted Elixhauser parameters (area under the curve: 0.665). Readmission risk ranged from 3% for patients with a score of 0 to 27% for those with a score of 8 or higher.

CONCLUSIONS

The Elixhauser comorbidity score already meets or exceeds the predictive discrimination of available risk calculators. Although insufficient by itself, this score represents a valuable summary of patient comorbidities and merits inclusion in any broader model predicting 90-day readmission risk after total joint arthroplasty.

LEVEL OF EVIDENCE

III.

Association Between Hospital Participation in Medicare Shared Savings Program Accountable Care Organizations and Readmission Following Major Surgery

OBJECTIVE

To evaluate the effect of Medicare Shared Savings Program accountable care organizations (ACOs) on hospital readmission after common surgical procedures.

SUMMARY BACKGROUND DATA

Hospital readmissions following surgery lead to worse patient outcomes and wasteful spending. ACOs, and their associated hospitals, have strong incentives to reduce readmissions from 2 distinct Centers for Medicare and Medicaid Services policies.

METHODS

We performed a retrospective cohort study using a 20% national Medicare sample to identify beneficiaries undergoing 1 of 7 common surgical procedures-abdominal aortic aneurysm repair, colectomy, cystectomy, prostatectomy, lung resection, total knee arthroplasty, and total hip arthroplasty-between 2010 and 2014. The primary outcome was 30-day risk-adjusted readmission rate. We performed difference-in-differences analyses using multilevel logistic regression models to quantify the effect of hospital ACO affiliation on readmissions following these procedures.

RESULTS

Patients underwent a procedure at one of 2974 hospitals, of which 389 were ACO affiliated. The 30-day risk-adjusted readmission rate decreased from 8.4% (95% CI, 8.1-8.7%) to 7.0% (95% CI, 6.7-7.3%) for ACO affiliated hospitals (P < 0.001) and from 7.9% (95% CI, 7.8-8.0%) to 7.1% (95% CI, 6.9-7.2%) for non-ACO hospitals (P < 0.001). The difference-in-differences of the 2 trends demonstrated an additional 0.52% (95% CI, 0.97-0.078%) absolute reduction in readmissions at ACO hospitals (P = 0.021), which would translate to 4410 hospitalizations avoided.

CONCLUSION

Readmissions following common procedures decreased significantly from 2010 to 2014. Hospital affiliation with Shared Savings ACOs was associated with significant additional reductions in readmissions. This emphasis on readmission reduction is 1 mechanism through which ACOs improve value in a surgical population.

A Novel Risk Calculator Predicts 90-Day Readmission Following Total Joint Arthroplasty

BACKGROUND

A reliable prediction tool for 90-day adverse events not only would provide patients with valuable estimates of their individual risk perioperatively, but would also give health-care systems a method to enable them to anticipate and potentially mitigate postoperative complications. Predictive accuracy, however, has been challenging to achieve. We hypothesized that a broad range of patient and procedure characteristics could adequately predict 90-day readmission after total joint arthroplasty (TJA).

METHODS

The electronic medical records on 10,155 primary unilateral total hip (4,585, 45%) and knee (5,570, 55%) arthroplasties performed at a single institution from June 2013 to January 2018 were retrospectively reviewed. In addition to 90-day readmission status, >50 candidate predictor variables were extracted from these records with use of structured query language (SQL). These variables included a wide variety of preoperative demographic/social factors, intraoperative metrics, postoperative laboratory results, and the 30 standardized Elixhauser comorbidity variables. The patient cohort was randomly divided into derivation (80%) and validation (20%) cohorts, and backward stepwise elimination identified important factors for subsequent inclusion in a multivariable logistic regression model.

RESULTS

Overall, subsequent 90-day readmission was recorded for 503 cases (5.0%), and parameter selection identified 17 variables for inclusion in a multivariable logistic regression model on the basis of their predictive ability. These included 5 preoperative parameters (American Society of Anesthesiologists [ASA] score, age, operatively treated joint, insurance type, and smoking status), duration of surgery, 2 postoperative laboratory results (hemoglobin and blood-urea-nitrogen [BUN] level), and 9 Elixhauser comorbidities. The regression model demonstrated adequate predictive discrimination for 90-day readmission after TJA (area under the curve [AUC]: 0.7047) and was incorporated into static and dynamic nomograms for interactive visualization of patient risk in a clinical or administrative setting.

CONCLUSIONS

A novel risk calculator incorporating a broad range of patient factors adequately predicts the likelihood of 90-day readmission following TJA. Identifying at-risk patients will allow providers to anticipate adverse outcomes and modulate postoperative care accordingly prior to discharge.

LEVEL OF EVIDENCE

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

A US hospital budget impact analysis of a skin closure system compared with standard of care in hip and knee arthroplasty

Background

Medicare’s mandatory bundle for hip and knee arthroplasty necessitates provider accountability for quality and cost of care to 90 days, and wound closure may be a key area of consideration. The DERMABOND^® PRINEO^® Skin Closure System (22 cm) combines a topical skin adhesive with a self-adhering mesh without the need for dressing changes or suture or staple removal. This study estimated the budget impact of the Skin Closure System compared to other wound closure methods for hip and knee arthroplasty.

Methods

A 90-day economic model was developed assuming 500 annual hip/knee arthroplasties for a typical US hospital setting. In current practice, wound closure methods for the final skin layer were set to 50% sutures and 50% staples. In future practice, this distribution shifted to 20% sutures, 20% staples, and 60% Skin Closure System. Health care resources included materials (eg, staplers, steri-strips, and traditional/barbed sutures), standard or premium dressings, outpatient visits, and home care visits. An Expert Panel, comprised of three orthopedic physician assistants, two orthopedic surgeons, and a home health representative, was used to inform several model parameters. Other inputs were informed by national data or literature. Unit costs were based on list prices in 2016 US dollars. Uncertainty in the model was explored through one-way sensitivity and alternative scenario analyses.

Results

The analysis predicted that use of Skin Closure System in the future practice could achieve cost savings of $56.70 to $79.62 per patient, when standard or premium wound dressings are used, respectively. This translated to an annual hospital budgetary savings ranging from $28,349 to $39,809 when assuming 500 arthroplasties. Dressing materials and postoperative health care visits were key model drivers.

Conclusions

Use of the Skin Closure System may provide cost savings within hip and knee arthroplasties due to decreases in resource utilization in the postacute care setting.

Effectiveness of a Model Bundle Payment Initiative for Femur Fracture Patients

OBJECTIVES

To analyze the effectiveness of a Bundled Payment for Care Improvement (BPCI) initiative for patients who would be included in a future potential Surgical Hip and Femur Fracture Treatment bundle.

DESIGN

Retrospective cohort.

SETTING

Single Academic Institution.

PATIENTS/PARTICIPANTS

Patients discharged with operative fixation of a hip or femur fracture (Diagnosis-Related Group codes 480-482) between January 2015 and October 2016 were included. A BPCI initiative based on an established program for BPCI total joint arthroplasty was initiated for patients with hip and femur fractures in January 2016. Patients were divided into nonbundle (care before initiative) and bundle (care with initiative) cohorts.

INTERVENTION

Application of BPCI principles.

MAIN OUTCOME MEASURES

Length of stay, location of discharge, and readmissions.

RESULTS

One hundred sixteen patients participated in the "institutional bundle," and 126 received care before the initiative. There was a trend toward decreased mean length of stay (7.3 ± 6.3 days vs. 6.8 ± 4.0 days, P = 0.457) and decreased readmission within 90 days (22.2% vs. 18.1%, P = 0.426). The number of patients discharged home doubled (30.2% vs. 14.3%, P = 0.008). There was no difference in readmission rates in bundle versus nonbundle patients based on discharged home status; however, bundle patients discharged to a skilled nursing facility trended toward less readmissions than nonbundle patients discharged to a skilled nursing facility (37.3% vs. 50.6%, P = 0.402). Mean episode cost reduction due to initiative was estimated to be $6450 using Medicare reimbursement data.

CONCLUSION

This study demonstrates the potential success of a BPCI initiative at 1 institution in decreasing postacute care facility utilization and cost of care when used for a hip and femur fracture population.

LEVEL OF EVIDENCE

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

Cost Determinants in the 90-Day Management of Isolated Ankle Fractures at a Large Urban Academic Hospital

OBJECTIVES

To determine the independent risk factors associated with increasing costs and unplanned hospital readmissions in the 90-day episode of care (EOC) for isolated operative ankle fractures at our institution.

DESIGN

Retrospective cohort study.

SETTING

Level I Trauma Center.

PATIENTS

Two hundred ninety-nine patients undergoing open reduction internal fixation for the treatment of an acute, isolated ankle fracture between 2010 and 2015.

INTERVENTION

None.

MAIN OUTCOME MEASURES

Independent risk factors for increasing 90-day EOC costs and unplanned hospital readmission rates.

RESULTS

Orthopaedic (64.9%) and podiatry (35.1%) patients were included. The mean index admission cost was $14,048.65 ± $5,797.48. Outpatient cases were significantly cheaper compared to inpatient cases ($10,164.22 ± $3,899.61 vs. $15,942.55 ± $5,630.85, respectively, P < 0.001). Unplanned readmission rates were 5.4% (16/299) and 6.7% (20/299) at 30 and 90 days, respectively, and were often (13/20, 65.0%) due to surgical site infections. Independent risk factors for unplanned hospital readmissions included treatment by the podiatry service (P = 0.024) and an American Society of Anesthesiologists score of ≥3 (P = 0.017). Risk factors for increasing total postdischarge costs included treatment by the podiatry service (P = 0.011) and male gender (P = 0.046).

CONCLUSIONS

Isolated operative ankle fractures are a prime target for EOC cost containment strategy protocols. Our institutional cost analysis study suggests that independent financial clinical risk factors in this treatment cohort includes podiatry as the treating surgical service and patients with an American Society of Anesthesiologists score ≥3, with the former also independently increasing total postdischarge costs in the 90-day EOC. Outpatient procedures were associated with about a one-third reduction in total costs compared to the inpatient subgroup.

Same-Hospital Re-Admission Rate Is Not Reliable for Measuring Post-Operative Infection-Related Re-Admission

BACKGROUND

Post-operative infections cause morbidity, consume resources, and are an important quality measure in assessing and comparing hospitals. Commonly used metrics do not account for re-admission to a different hospital. The Nationwide Readmissions Database (NRD) tracks re-admissions across United States (US) hospitals. Infection-related re-admission across US hospitals has not been studied previously.

PATIENTS AND METHODS

The 2013 NRD was queried for admissions with a primary International Classification of Diseases and Related Health Problems, 9th revision, Clinical Modification code for the most frequently performed operations. Non-elective all-cause, infection-related, and different hospital 30-day re-admission rates were calculated, using All Patient Refined Diagnosis Related Groups codes. Multi-variable logistic regression identified risk factors for re-admission.

RESULTS

Of 826,836 surviving to discharge, 39,281 (4.8%) had an unplanned re-admission within 30 days, occurring at a different hospital 20.5% of the time. The most common reason for re-admission was infection (25.1%). Orthopedic and spinal procedures were at highest risk for all-cause and infection-related different hospital re-admission. Infection-related different hospital re-admission risk factors included: Length of stay >30 days (odds ratio [OR] 2.28 [1.62-3.21], p < 0.01), age ≥65 years (OR 1.56 [1.38-1.76], p < 0.01), and Charlson Comorbidity Index >1 (OR 1.14 [1.01-1.28], p < 0.01) and differed from predictors of same-hospital infectious re-admission. Non-elective surgical procedure (OR 0.79 [0.72-0.87], p < 0.01) and initial hospitalization at a large hospital (OR 0.66 [0.59-0.74], p < 0.01) were protective.

CONCLUSION

A substantial proportion of post-operative re-admissions are missed by same-hospital re-admission data. All-cause and infection-related post-operative re-admissions to a different hospital are affected by unique patient and institution-specific factors. Re-admission reduction programs, quality metrics, and policy based on same hospital re-admission data should be updated to incorporate different hospital re-admission.

Improving Quality and Decreasing Cost by Reducing Re-admissions in Patients Undergoing Total Joint Arthroplasty

PURPOSE OF REVIEW

Total joint arthroplasty (TJA) has had an increased demand over the recent years. It is a successful procedure, and there are relatively few complications, but there is a high overall cost. There is a push to increase the quality of care, lessen complications, and decrease cost by reducing readmissions. This article will discuss the risk factors that can contribute to the complication and readmission rates following TJA.

RECENT FINDINGS

Several risk factors have been found to contribute to the complication and readmission rates following a TJA. It is important to understand these risk factors and mitigate them as much as possible in order to optimize the patient experience. There are risk factors that cannot be modified, and the treatment team as well as the patient should be made aware of these and account for them when making the decision whether to undergo elective primary TJA or not. In general, an increased number of risk factors is associated with increased complications and increased readmission rates. At our institution, we have used this knowledge to improve our outcomes and decrease costs. It is important to be mindful of risk factors for poor outcomes prior to performing TJA. This allows for the optimization of patients prior to undergoing surgery. This can lead to improved outcomes at a lower cost.