Do Aggregate Socioeconomic Status Factors Predict Outcomes for Total Knee Arthroplasty in a Rural Population?

Impacts of neighborhood deprivation on septic and aseptic revision total knee arthroplasty outcomes: A comprehensive analysis using the area deprivation index

BACKGROUND

Community deprivation has been linked to poor health outcomes following primary total knee arthroplasty (pTKA), but few studies have explored revision TKA (rTKA). The present study analyzed implications of neighborhood deprivation on rTKA outcomes by characterizing relationships between Area Deprivation Index (ADI) and (1) non-home discharge disposition (DD), (2) hospital length of stay (LOS), (3) 90-day emergency department (ED) visits, (4) 90-day hospital readmissions, and (5) the effect of race on these healthcare outcomes.

METHODS

A total of 1,434 patients who underwent rTKA between January 2016 and June 2022 were analyzed. Associations between the ADI and postoperative healthcare resource utilization outcomes were evaluated using multivariate logistic regression. Mediation effect was estimated using a nonparametric bootstrap resampling method.

RESULTS

Greater ADI was associated with non-home DD (p < 0.001), LOS ≥ 3 days (p < 0.001), 90-day ED visits (p = 0.015), and 90-day hospital readmission (p = 0.002). Although there was no significant difference in ADI between septic and aseptic patients, septic patients undergoing rTKA were more likely to experience non-home discharge (p < 0.001), prolonged LOS (p < 0.001), and 90-day hospital readmission (p = 0.001). The effect of race on non-home DD was found to be mediated via ADI (p = 0.038). Similarly, results showed the effect of race on prolonged LOS was mediated via ADI (p = 0.01).

CONCLUSION

A higher ADI was associated with non-home discharge, prolonged LOS, 90-day ED visits, and 90-day hospital readmissions. The impacts of patient race on both non-home discharge and prolonged LOS were mediated by ADI. This index allows clinicians to better understand and address disparities in rTKA outcomes.

Racial and Ethnic Disparities in Primary Total Knee Arthroplasty Outcomes: A Systematic Review and Meta-Analysis of Two Decades of Research

Racial disparities in outcomes following total knee arthroplasty (TKA) remain persistent. This systematic review and meta-analysis aims to comprehensively synthesize data between 2000-2020. An electronic search of studies was performed on PubMed, SCOPUS, and the Cochrane Library databases from January 1, 2000, and December 31, 2020. Random effects models were used to report unadjusted and adjusted estimates for a comprehensive list of care outcomes in TKA. 63 studies met PRISMA criteria. Black patients report greater odds of in-hospital mortality (odds ratio [OR]: 1.37, 95% CI: 1.00-1.59 (p = 0.049); adjusted OR [aOR]: 1.34, 95% CI: 1.09-1.64), in-hospital complications (OR: 1.31, 95% CI: 1.27-1.35), 30-day complications (aOR: 1.19, 95% CI: 1.07-1.33), infection (OR: 1.11, 95% CI: 1.07-1.16; aOR: 1.30, 95% CI: 1.16-1.46), bleeding (OR: 1.33, 95% CI: 1.03-1.71; aOR: 1.47, 95% CI: 1.23-1.75), peripheral vascular events (PVE) (aOR: 1.46, 95% CI: 1.11-1.92), length of stay (LOS) (OR: 1.20, 95% CI: 1.08-1.34), extended-LOS (aOR: 1.89, 95% CI: 1.53-2.33), discharge disposition (OR: 1.59, 95% CI: 1.29-1.96; aOR: 1.96, 95% CI: 1.70-2.25), 30-day (OR: 1.20, 95% CI: 1.13-1.27; aOR: 1.17 95% CI: 1.09-1.26) and 90-day (OR: 1.46, 95% CI: 1.17-1.82) readmission compared to White patients. Disparities in bleeding, extended-LOS, discharge disposition, PVE, and 30-day readmission were observed in Asian patients. Hispanic patients experienced disparities in extended LOS and discharge disposition, while Native-American patients had disparities in bleeding outcomes. Persistent racial disparities in TKA outcomes highlight a need for standardized outcome measures and comprehensive data collection across multiple racial groups to ensure greater healthy equity.

How Does the Physician Patient Fare After Primary Total Hip and Knee Arthroplasty?

Background

Physician patients requiring surgery present with occupational risks and personality traits that may affect outcomes. This study compared implant survivorship, complications, and clinical outcomes of physicians undergoing primary total hip arthroplasty (THA) or total knee arthroplasty (TKA).

Methods

A retrospective review of our institutional total joint registry identified 185 physicians undergoing primary THA (n = 94) or TKA (n = 91). Physicians were matched 1:2 with nonphysician controls according to age, sex, body mass index, joint (hip or knee), and surgical year. Physician type (medical, n = 132 vs surgical, n = 53) subanalysis was performed. Implant survivorship was assessed via Kaplan-Meier methods. Clinical outcomes were evaluated by Harris hip scores and Knee Society Scores. Mean follow-up was 5 years.

Results

There was no significant difference in 5-year implant survivorship free of any reoperation (P > .5) or any revision (P > .2) between physician and nonphysician patients after THA and TKA. Similarly, the 90-day complication risk was not significantly different after THA or TKA (P = 1.0 for both). Physicians and nonphysicians demonstrated similar improvement in Harris hip scores (P = .6) and Knee Society Scores (P = .4). When comparing physician types, there was no difference in implant survivorship (P > .4), complications (P > .6), or patient reported outcomes (P > .1).

Conclusions

Physician patients have similar implant survivorship, complications, and clinical outcomes when compared to nonphysicians after primary THA and TKA. Physicians should feel reassured that their profession does not appear to increase risks when undergoing lower extremity total joint arthroplasty.

The Utility of the Area Deprivation Index in Assessing Complications After Total Joint Arthroplasty

Background

Vulnerable populations, including patients from a lower socioeconomic status, are at an increased risk for infection, revision surgery, mortality, and complications after total joint arthroplasty (TJA). An effective metric to quantify and compare these populations has not yet been established in the literature. The Area Deprivation Index (ADI) provides a composite area-based indicator of socioeconomic disadvantage consisting of 17 U.S. Census indicators, based on education, employment, housing quality, and poverty. We assessed patient risk factor profiles and performed multivariable regressions of total complications at 30 days, 90 days, and 1 year.

Methods

A prospectively collected database of 3,024 patients who underwent primary elective total knee arthroplasty or total hip arthroplasty performed by 3 fellowship-trained orthopaedic surgeons from January 1, 2015, through December 31, 2021, at a tertiary health-care center was analyzed. Patients were divided into quintiles (ADI ≤20 [n = 555], ADI 21 to 40 [n = 1,001], ADI 41 to 60 [n = 694], ADI 61 to 80 [n = 396], and ADI 81 to 100 [n = 378]) and into groups based on the national median ADI, ≤47 (n = 1,896) and >47 (n = 1,128).

Results

Higher quintiles had significantly more females (p = 0.002) and higher incidences of diabetes (p < 0.001), congestive heart failure (p < 0.001), chronic obstructive pulmonary disease (p < 0.001), hypertension (p < 0.001), substance abuse (p < 0.001), and tobacco use (p < 0.001). When accounting for several confounding variables, all ADI quintiles were not associated with increased total complications at 30 days, but age (p = 0.023), female sex (p = 0.019), congestive heart failure (p = 0.032), chronic obstructive pulmonary disease (p = 0.001), hypertension (p = 0.003), and chronic kidney disease (p = 0.010) were associated. At 90 days, ADI > 47 (p = 0.040), female sex (p = 0.035), and congestive heart failure (p = 0.001) were associated with increased total complications.

Conclusions

Balancing intrinsic factors, such as patient demographic characteristics, and extrinsic factors, such as social determinants of health, may minimize postoperative complications following TJA. The ADI is one tool that can account for several extrinsic factors, and can thus serve as a starting point to improving patient education and management in the setting of TJA.

Level of Evidence

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

Social Determinants of Health Disparities Increase the Rate of Complications After Total Knee Arthroplasty

BACKGROUND

Few studies have investigated whether social determinants of health disparities (SDHD), which include economic, social, education, health care, and environmental factors, identified through International Classification of Diseases (ICD) codes are associated with increased odds for poor health outcomes. We aimed to investigate the association between SDHD, identified through this novel methodology, as well as postoperative complications following total knee arthroplasty (TKA).

METHODS

Using a national insurance claims database, a retrospective cohort analysis was performed. Patients were selected using Current Procedural Terminology and ICD codes for primary TKA between 2010 and 2019. Patients were stratified into 2 groups using ICD codes, those who had SDHD and those who did not, and propensity matched 1:1 for age, sex, a comorbidity score, and other comorbidities. After matching, 207,844 patients were included, with 103,922 patients in each cohort. Odds ratios (ORs) for 90-day medical and 2-year surgical complications were obtained using multivariable logistical regressions.

RESULTS

In patients who have SDHD, multivariable analysis demonstrated higher odds of readmission (OR): 1.12; P = .013) and major and minor medical complications (OR: 2.09; P < .001) within 90-days as well as higher odds of revision surgery (OR: 1.77; P < .001) and periprosthetic joint infection (OR: 1.30; P < .001) within 2-years.

CONCLUSION

The SDHD are an independent risk factor for revision surgery and periprosthetic joint infection after TKA. In addition, SDHD is also an independent risk factor for all-cause hospital readmissions and both minor and major complications.

LEVEL OF EVIDENCE

III.

Concentrated Economic Disadvantage Predicts Resource Utilization After Total Knee Arthroplasty

BACKGROUND

The Index of Concentration at the Extremes (ICE), a measure of geographic socioeconomic polarization, predicts several health outcomes but has not been evaluated concerning total knee arthroplasty (TKA). This study evaluates ICE as a predictor of post-TKA resource utilization.

METHODS

Using the Healthcare Cost and Utilization Project's New York State database from 2016 to 2017, we retrospectively evaluated 57,426 patients ≥50 years undergoing primary TKA. The ICE values for extreme concentrations of income and race were calculated using United States Census Bureau data with the formula ICEi = (Pi-Di)/Ti where Pi, Di, and Ti are the number of households in the most privileged extreme, disadvantaged extreme, and total population in zip code i, respectively. Extremes of privilege and disadvantage were defined as ≥$150,000 versus <$25,000 for income and non-Hispanic White versus non-Hispanic Black for race. Association of ICE values, demographics, and comorbidities with 90-day readmission and 90-day emergency department (ED) visits was examined using multivariable analysis.

RESULTS

Overall 90-day readmission and ED visit rates were 12.8% and 9.4%, respectively. On multivariable analysis, the lowest ICEIncome quintile (concentrated poverty) predicted 90-day readmission (odds ratio 1.17, 95% confidence interval 1.05 to 1.30, P = .005) and 90-day ED visit (odds ratio 1.22, 95% confidence interval 1.08 to 1.38, P = .001). The ICERace was not predictive of either outcome.

CONCLUSION

Patients in communities with the lowest ICEIncome values use more inpatient and ED resources after primary TKA. Incorporating ICEIncome into risk-adjusted payment models may help align incentives for equitable care.

Does interaction occur between risk factors for revision total knee arthroplasty?

INTRODUCTION

Several risk factors for revision TKA have previously been identified, but interactions between risk factors may occur and affect risk of revision. To our knowledge, such interactions have not been previously studied. As patients often exhibit multiple risk factors for revision, knowledge of these interactions can help improve risk stratification and patient education prior to TKA.

MATERIALS AND METHODS

The State Inpatient Databases (SID), part of the Healthcare Cost and Utilization Project (HCUP), were queried to identify patients who underwent TKA between January 1, 2006 and December 31, 2015. Risk factors for revision TKA were identified, and interactions between indication for TKA and other risk factors were analyzed.

RESULTS

Of 958,944 patients who underwent TKA, 33,550 (3.5%) underwent revision. Age, sex, race, length of stay, Elixhauser readmission score, urban/rural designation, and indication for TKA were significantly associated with revision (p < 0.05). Age was the strongest predictor (p  < 0.0001), with younger patients exhibiting higher revision risk. Risks associated with age were modified by an interaction with indication for TKA (p < 0.0001). There was no significant interaction between sex and indication for TKA (p = 0.535) or race and indication for TKA (p = 0.187).

CONCLUSIONS

Age, sex, race, length of stay, Elixhauser readmission score, urban/rural designation, and indication for TKA are significantly associated with revision TKA. Interaction occurs between age and indication.

The Benefit in Patient-Reported Outcomes After Total Knee Arthroplasty was Comparable Across Income Quartiles

BACKGROUND

Few studies have assessed how socioeconomic status (SES) influences patient-reported outcomes (PROMs) after total knee arthroplasty (TKA). This study evaluated the impact of patient median ZIP code income levels on PROMs after TKA.

METHODS

We retrospectively reviewed patients at our institution undergoing primary, unilateral TKA from 2017 to 2020. Patients who did not have one-year postoperative PROMs were excluded. Patients were stratified based on the quartile of their home ZIP code median income from United States Census Bureau data. There were 1,267 patients included: 98 in quartile 1 (median income ≤ $46,308) (7.7%); 126 in quartile 2 (median income $46,309-$57,848) (10.0%); 194 in quartile 3 (median income $57,849-$74,011) (15.7%); and 849 in quartile 4 (median income ≥ $74,012) (66.4%). We collected baseline demographic data, 2-year outcomes, and PROMs preoperatively, as well as at 12 weeks and one year, postoperatively.

RESULTS

The Knee Injury and Osteoarthritis Outcome Score for Joint Replacement was significantly higher in quartile 4 preoperatively (P < .001), 12 weeks postoperatively (P < .001), and one year postoperatively (P < .001). There were no significant differences in delta improvements of Knee Injury and Osteoarthritis Outcome Score for Joint Replacement from preoperative to 12 weeks or one year postoperatively. There were no significant differences in lengths of stay, discharge dispositions, readmissions, or revisions.

CONCLUSION

Patients from lower income areas have slightly worse knee function preoperatively and worse outcomes following TKA. However, improvements in PROMs throughout the first year postoperatively are similar across income quartiles, suggesting that patients from lower income quartiles achieve comparable therapeutic benefits from TKA.

LEVEL III EVIDENCE

Retrospective Cohort Study.

What is the Impact of Social Deprivation on Mental and Physical Health Before and After Primary Total Knee Arthroplasty?

Background

The purpose of the present study was to investigate the relationship between socioeconomic status and Patient-Reported Outcomes Measurement Information System Global Health (PROMIS-GH) scores before and after primary total knee arthroplasty (TKA). We hypothesized that patients with greater social deprivation would have lower PROMIS-GH scores at 3 months and 1 year following primary TKA.

Methods

We retrospectively reviewed data from patients who underwent unilateral primary TKA and completed PROMIS-GH preoperatively and at 3 months (n = 257) or 1 year (n = 154) postoperatively. Area Deprivation Index (ADI), calculated from 9-digit zip codes, was used to measure social deprivation. Participants were grouped into quartiles by ADI score. Minimal clinically important difference in PROMIS-GH mental (PROMIS-MH) and physical health (PROMIS-PH) component scores were compared between ADI groups.

Results

Participants in the highest ADI quartile (most disadvantaged) had significantly lower PROMIS-MH and PROMIS-PH scores at every time point relative to the lowest ADI quartile (least disadvantaged) (P < .05 for all). Both ADI groups experienced significant improvements in PROMIS-PH following TKA (P < .001 for all), but not in PROMIS-MH (P > .05 for all) at 3-months and 1-year postoperatively. Magnitude of improvement in PROMIS-PH and rates of achievement of minimal clinically important difference did not significantly differ between ADI groups (P > .05 for all).

Conclusions

Socially disadvantaged patients benefit equally from primary TKA but are more likely to have persistently lower 1-year postoperative PROMIS-GH scores relative to less disadvantaged patients. Social deprivation should be accounted for when using PROMIS-GH to assess clinical outcomes for research and quality measures.

Level of Evidence

IV, retrospective cohort study.

Socioeconomic Challenges in the Rural Patient Population in Need of Total Joint Arthroplasty

Many challenges exist for the rural patient in need of joint arthroplasty. Optimization for surgery is more difficult due to factors such as deprivation, education, employment, household income, and access to proper surgical institutions. Rural individuals have less access to primary care and even less access to surgical specialists, creating a distinct subset of patients who endure higher costs, poorer outcomes, and lack of care. Reducing socioeconomic disparities in rural communities will require policy initiatives addressing the components of socioeconomic status (income, education, and occupation). Hopefully remote patient technologies can help with access and timely addressing of modifiable risk factors.

Racial Disparities in Rates of Revision and use of Modern Features in Total Knee Arthroplasty, a National Registry Study

BACKGROUND

The purpose of our study was to investigate the association of race and ethnicity with rates of modern implant use and postoperative outcomes in total knee arthroplasty (TKA) using the American Academy of Orthopaedic Surgeons American Joint Replacement Registry.

METHODS

Adult TKAs from 2012 to 2020 were queried from the American Joint Replacement Registry. A total of 1,121,457 patients were available for analysis for surgical features and 1,068,210 patients for analysis of outcomes. Mixed-effects multivariable logistic regression models were used to examine the association of race with each individual surgical feature (unicompartmental knee arthroplasty (UKA) and robotic-assisted TKA (RA-TKA)) and 30- and 90-day readmission. A proportional subdistribution hazard model was used to model the risk of revision TKA.

RESULTS

On multivariate analyses, compared to White patients, Black (odds ratio (OR): 0.52 P < .0001), Hispanic (OR 0.75 P < .001), and Native American (OR: 0.69 P = .0011) patients had lower rates of UKA, while only Black patients had lower rates of RA-TKA (OR = 0.76 P < .001). White (hazard ratio (HR) = 0.8, P < .001), Asian (HR = 0.51, P < .001), and Hispanic-White (HR = 0.73, P = .001) patients had a lower risk of revision TKA than Black patients. Asian patients had a lower revision risk than White (HR = 0.64, P < .001) and Hispanic-White (HR = 0.69, P = .011) patients. No significant differences existed between groups for 30- or 90-day readmissions.

CONCLUSION

Black, Hispanic, and Native American patients had lower rates of UKA compared to White patients, while Black patients had lower rates of RA-TKA compared to White, Asian, and Hispanic patients. Black patients also had higher rates of revision TKA than other races.

The Impact of Surgeon Variability on Patient-Reported Outcome Measures, Length of Stay, Discharge Disposition, and 90-Day Readmission in TKA

BACKGROUND

Studies involving total knee arthroplasty (TKA) have focused on patient-related factors as drivers of outcomes. Although some studies have investigated surgeon and/or surgery-level factors (i.e., approach, volume), the measure of variance in postoperative outcomes across surgeons following TKA has not been determined. The aim of the current study was to evaluate the relationship between the surgeon and 1-year patient-reported outcome measures, the length of stay, the discharge disposition, and 90-day readmission after TKA, as well as the differences in these variables among surgeons.

METHODS

Data were prospectively collected for 5,429 patients who underwent TKA at a large health-care system with 36 surgeons between 2016 and 2018. Likelihood ratio tests were performed to investigate the relationship between surgeon and the 1-year Knee injury and Osteoarthritis Outcome Score (KOOS)-Pain subscale, KOOS-Physical Function Shortform (KOOS-PS), KOOS for Joint Replacement (KOOS-JR), patient acceptable symptom state (PASS), length of stay, discharge disposition, and 90-day readmission. The minimal clinically important difference (MCID) was used to assess meaningful outcomes. Variable importance was determined by the Akaike information criterion (AIC) increase, using ordinal and binary-response mixed-effect models.

RESULTS

There was a significant association between surgeon and KOOS-Pain (p < 0.001), KOOS-PS (p = 0.001), KOOS-JR (p < 0.001), PASS (p = 0.024), length of stay (p < 0.001), discharge disposition (p < 0.001), and 90-day readmission (p < 0.001). When modeling 1-year KOOS-Pain (AIC increase, 15.6), KOOS-PS (AIC increase, 6.8), KOOS-JR (AIC increase, 13.5), PASS (AIC increase, 1.9), length of stay, and discharge disposition, the surgeon variable contributed more to the 1-year outcome than some patient-level factors (e.g., body mass index, Charlson Comorbidity Index). The difference between the highest and lowest median probabilities of attaining the same value for the KOOS-Pain (11.2%), KOOS-PS (9.4%), KOOS-JR (11.8%), PASS (5.9%), length of stay (46.6%), discharge disposition (22.8%), and readmission (13.1%) indicated surgeon-level variability.

CONCLUSIONS

Surgeon-related factors may be stronger contributors to the 1-year patient-reported outcome measures and length of stay than patient characteristics emphasized in the literature. Current findings have suggested variability in patient-reported outcome measures, length of stay, discharge location, and 90-day readmission among surgeons. Surgeon variability should be considered when model-fitting in the setting of TKA.

LEVEL OF EVIDENCE

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

Neighborhood Socioeconomic Disadvantages Associated With Prolonged Lengths of Stay, Nonhome Discharges, and 90-Day Readmissions After Total Knee Arthroplasty

BACKGROUND

Low socioeconomic status and neighborhood context has been linked to poor health care outcomes after total knee arthroplasty (TKA). The area deprivation index (ADI) addresses this relationship by ranking neighborhoods by socioeconomic disadvantage. We examined the following relationships of the ADI among TKA recipients: (1) patient demographics, (2) lengths of stay (LOS), (3) nonhome discharges, and (4) 90-day readmissions, emergency department visits, and reoperations.

METHODS

We reviewed a consecutive series of primary TKAs from 2018 through 2020 at a tertiary health care system. A total of 3928 patients who had complete ADI data were included. A plurality of patients (14.9%) were categorized within ADI 31-40, below the national median ADI of 47. Associations between the national ADI decile and 90-day postoperative health care utilization metrics were evaluated using multivariate regressions (adjusted for patient demographics and comorbidities).

RESULTS

The 91-100 ADI cohort was disproportionately African American, female, younger, and smokers. Compared with ADI 31-40 (reference), the ADI 61-70 cohort was associated with higher odds of LOS ≥3 days (odds ratio [OR] = 1.6 [1.08-2.36], P = .019) and nonhome discharges (OR = 1.73 [1.08-2.75], P = .021). The ADI 91-100 cohort was associated with the highest odds of prolonged LOS (OR = 2.27; [1.47-3.49], P < .001), nonhome discharges (OR = 3.49 [2.11-5.78], P < .001), and all-cause readmissions (OR: 1.79, [1.02-3.14], P = .044). No significant associations were found between the ADI and 90-day emergency department visits or reoperations (P > .05).

CONCLUSION

A higher ADI was associated with prolonged LOS, nonhome discharge status, and 90-day readmissions after TKA. This index highlights potential areas of intervention for assessing health care outcomes.

Understanding factors affecting 30-day unplanned readmissions for patients undergoing total knee arthroplasty (TKA): the ACT Transition from Hospital to Home Orthopaedics Survey

OBJECTIVES

The aim of this study was to investigate factors associated with unplanned 30-day readmissions following a total knee arthroplasty (TKA), including association with post-hospital syndrome, patient enablement and transition from hospital to home.

DESIGN, SETTING AND PARTICIPANTS

A cross-sectional written survey of public and private patients attending a 6-week follow-up appointment after TKA at one of four clinical services in the Australian Capital Territory (ACT) between 1 February 2018 and 31 January 2019. Multiple logistic regression analyses were used to measure associations between patient, hospital and transitional care factors with unplanned 30-day readmissions, while controlling for known confounders.

RESULTS

Of the 380 participants who completed the survey (n=380, 54% of TKAs undertaken over the study period), 3.4% (n=13; 95% CI: 1.8 to 5.8) were subsequently readmitted within 30 days of discharge after a primary hospitalisation. Public patients were significantly more likely to be readmitted within 30 days compared with private patients (adjusted OR=6.31, 95% CI: 1.59 to 25.14, p=0.009), and patients who attended rehabilitation were significantly less likely to be readmitted within 30 days of discharge than those who did not (adjusted OR=0.16, 95% CI: 0.04 to 0.57, p=0.005). There were no associations between post-hospital syndrome or patient enablement and 30-day readmissions in this study.

CONCLUSION

Reasons underlying the difference in unplanned readmission rates for public versus private patients need to be explored, including differences in surgical waiting times and the consequences for impairment and disease complexity. Strategies to foster increased participation post-surgical rehabilitation programmes need to be developed as an avenue to mitigate the burden of unplanned 30-day readmissions on individuals and health systems.

Black and Hispanic Patients Do Not Stay Longer After Primary Total Knee Arthroplasty: Results From an Urban Center Serving a Predominantly Minority Cohort

INTRODUCTION

Previous reports identified minority race/ethnicity to be an independent risk factor for prolonged length of stay (LOS); however, these cohorts consisted of predominantly White patients. This study sought to evaluate minority status as an independent risk factor for prolonged LOS after primary total knee arthroplasty (TKA) in a predominantly Hispanic and Black cohort.

METHODS

This was a retrospective study using an institutional database of patients who underwent primary TKA between the years 2016 and 2019. Demographic and socioeconomic data, smoking, body mass index (BMI), medical comorbidities, discharge disposition, and 30-day readmission rates were collected. Patients were first categorized into racial/ethnic groups (Hispanic, Black, or White). An univariate analysis was performed comparing patient characteristics between racial/ethnic groups using the Wilcoxon rank sum, chi-squared, and Fisher exact tests. We then categorized patients into two groups-normal LOS (discharged on postoperative day 1 to 2) and prolonged LOS (discharged after postoperative day 2). An univariate analysis was again performed comparing patient characteristics between LOS groups using Wilcoxon rank sum, chi-squared, and Fisher exact tests. After identifying risk factors markedly associated with LOS, a multivariate logistic regression analysis was performed to identify independent risk factors for prolonged LOS.

RESULTS

A total of 3,093 patients were included-47.9% Hispanic and 38.3% Black. Mean LOS was 2.9 ± 1.6 days. An univariate analysis found race/ethnicity, age, low socioeconomic status (SES), discharge disposition, insurance type, weekday of surgery, BMI >40, smoking, increased American Society of Anesthesiologists (ASA)/Charlson Comorbidity Index (CCI) and several medical comorbidities to be associated with prolonged LOS (P < 0.05). A multivariate logistic regression analysis found Black and Hispanic patients were less likely to have prolonged LOS after adjusting for associated risk factors. White race/ethnicity, nonhome discharge, low SES, weekday of surgery, smoking, BMI >40, and increased ASA and CCI were identified as independent risk factors for prolonged LOS (P < 0.05). The overall 30-day readmission rate was 3.6%, with no notable difference between racial/ethnic and LOS groups (P = 0.98 and P = 0.78).

CONCLUSION

In contrast to previous reports, our study found that after adjusting for associated risk factors, minority patients do not have prolonged LOS after primary TKA in an urban, socioeconomically disadvantaged, predominantly minority patient cohort. White race/ethnicity, nonhome discharge, low SES, weekday of surgery, smoking, BMI >40, increased CCI, and ASA were all found to be independent risk factors for prolonged LOS. These findings highlight the need to further investigate the role of race/ethnicity on LOS after primary TKA using large-scale, randomized controlled trials with equally represented patient cohorts.

Patient-reported outcomes of a short hospital stay after total knee replacement in a regional public hospital: a prospective cohort treated 2018-2019

BACKGROUND

Patient-reported outcomes and satisfaction following short length of stay (LoS) after total knee arthroplasty (TKA) in the Australian regional context remain unexplored. This study reports complications, outcomes and satisfaction of patients discharged from an enhanced recovery protocol (ERP), 6 weeks after TKA in a regional hospital.

METHODS

Prospective recruitment occurred between 2018 and 2019. Demographics, intraoperative data, complications and emergency department (ED) presentations were retrieved from hospital records. Complications were graded for severity using a published scale. Knee range of motion (ROM), timed up-and-go (TUG), 6-min walk test (6MWT) and Oxford Knee Scores (OKS) were assessed preoperatively and 6 weeks postoperatively. Patient satisfaction was assessed via questionnaire at the postoperative follow-up.

RESULTS

One hundred patients/117 primary TKAs were prospectively included. Median LoS was 2 days (interquartile range 1-3 days) with 74.4% and 88.4% of patients satisfied with their knee and LoS, at 6 weeks respectively. Twenty-seven patients presented to the ED a total of 37 times with complication severity of Grade III or less, and 10 patients were readmitted. Significant improvements in objective and subjective outcomes were observed, however only change in median OKS exceeded the minimal clinically important difference (MCID) threshold.

CONCLUSION

An enhanced recovery protocol after TKA in a regional hospital can achieve a median LoS of 2 days without compromising patient-reported outcomes and objective functional measures, whilst maintaining a high level of patient satisfaction with both the surgery and LoS. Further work is required to better optimize management of largely low-grade complications in this patient population.

Temporal Association of Pain Catastrophizing and Pain Severity Across the Perioperative Period: A Cross-Lagged Panel Analysis After Total Knee Arthroplasty

OBJECTIVE

Although numerous studies show that preoperative pain catastrophizing is a risk factor for pain after total knee arthroplasty (TKA), little is known about the temporal course of the association between perioperative pain catastrophizing and pain severity. The present study investigated temporal changes and their dynamic associations between pain catastrophizing and pain severity before and after TKA.

DESIGN

A secondary data analysis of a larger observational parent study featuring prospective repeated measurement over 12 months.

SETTING

Dual-site academic hospital.

SUBJECTS

A total of 245 individuals who underwent TKA.

METHODS

Participants completed pain catastrophizing and pain severity questionnaires at baseline, 6 weeks, and 3, 6, and 12 months after TKA. Cross-lagged panel analysis was conducted with structural equation modeling including age, sex, race, baseline anxiety, and depressive symptoms as covariates.

RESULTS

Reduction in pain catastrophizing from baseline to 6 weeks after TKA was associated with lower pain severity at 3 months after TKA (standardized β = 0.14; SE = 0.07, P = 0.046), while reduction in pain severity at 6 weeks after TKA was not associated with pain catastrophizing at 3 months after TKA (P = 0.905). In the chronic postsurgical period (>3 months), pain catastrophizing at 6 months after TKA predicted pain severity at 12 months after TKA (β = 0.23, P = 0.009) with controlling for auto-correlation and covariates, but not vice versa.

CONCLUSIONS

We provide evidence that changes in pain catastrophizing from baseline to 6 weeks after TKA are associated with subsequent pain severity. Future studies are warranted to determine whether targeting pain catastrophizing during the perioperative period may improve clinical outcomes for individuals undergoing TKA.

Comparison of Area Deprivation Index, Socioeconomic Parameters, and Preoperative Demographics With Postoperative Emergency Department Visits After Total Knee Arthroplasty

BACKGROUND

This study aims to determine if socioeconomic (SE) parameters, primarily area deprivation index (ADI), relate to postoperative emergency department (ED) visits after total knee arthroplasty (TKA).

METHODS

We retrospectively reviewed 2655 patients who underwent TKA in a health system of 4 hospitals. The primary outcome was an ED visit within 90 days, which was divided into those with and without readmission. SE parameters including ADI as well as preoperative demographics were analyzed. Univariable and multiple logistic regressions were performed determining risk of 90-day postoperative ED visits, as well as once in the ED, risks for readmission.

RESULTS

436 patients (16.4%) presented to the ED within 90 days. ADI was not a risk factor. The multiple logistic regression demonstrated men, Medicare or Medicaid, and preoperative ED visits were consistently risk factors for a postoperative ED visit with and without readmission. Preoperative anticoagulation was only a risk factor for ED visits with readmission. Among patients who visited the ED, if the patient was Caucasian, a lower BMI, or higher American Society of Anesthesiologists score, they were likely to be readmitted.

CONCLUSION

The study demonstrated that the percentage of early ED returns after TKA was high and that ADI was not a predictor for 90-day postoperative ED visit. The only SE factor that may contribute to this phenomenon was insurance type. Once in the ED, race, preoperative ED visits, preoperative anticoagulation, BMI, gender, and preoperative American Society of Anesthesiologists score contributed to a risk of readmission. The study supports hospitals' mission to provide equal access health care.

Higher body mass index is associated with larger postoperative improvement in patient-reported outcomes following total knee arthroplasty

BACKGROUND

Total knee arthroplasty is known to successfully alleviate pain and improve function in endstage knee osteoarthritis. However, there is some controversy with regard to the influence of obesity on clinical benefits after TKA. The aim of this study was to investigate the impact of body mass index (BMI) on improvement in pain, function and general health status following total knee arthroplasty (TKA).

METHODS

A single-centre retrospective analysis of primary TKAs performed between 2006 and 2016 was performed. Data were collected preoperatively and 12-month postoperatively using WOMAC score and EQ-5D. Longitudinal score change was compared across the BMI categories identified by the World Health Organization.

RESULTS

Data from 1565 patients [mean age 69.1, 62.2% women] were accessed. Weight distribution was: 21.2% BMI < 25.0 kg/m2, 36.9% BMI 25.0-29.9 kg/m2, 27.0% BMI 30.0-34.9 kg/m2, 10.2% BMI 35.0-39.9 kg/m2, and 4.6% BMI ≥ 40.0 kg/m2. All outcome measures improved between preoperative and 12-month follow-up (p < 0.001). In pairwise comparisons against normal weight patients, patients with class I-II obesity showed larger improvement on the WOMAC function and total score. For WOMAC pain improvements were larger for all three obesity classes.

CONCLUSIONS

Post-operative improvement in joint-specific outcomes was larger in obese patients compared to normal weight patients. These findings suggest that obese patients may have the greatest benefits from TKA with regard to function and pain relief one year post-op. Well balanced treatment decisions should fully account for both: Higher benefits in terms of pain relief and function as well as increased potential risks and complications. Trial registration This trial has been registered with the ethics committee of Eastern Switzerland (EKOS; Project-ID: EKOS 2020-00,879).

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Does racial background influence outcomes following total joint arthroplasty?

BACKGROUND

The purpose of this study is to assess whether racial differences influence patient-reported outcome measures (PROMs) following primary total hip (THA) and knee (TKA) arthroplasty.

METHODS

We retrospectively reviewed patients who underwent primary THA or TKA from 2016 to 2020 with available PROMs. Both THA and TKA patients were separated into three groups based on their ethnicity: Caucasian, African-American, and other races. Patient demographics, clinical data, and PROMs at various time-periods were collected and compared. Demographic differences were assessed using chi-square and ANOVA. Univariate ANCOVA was utilized to compare outcomes and PROMs while accounting for demographic differences.

RESULTS

This study included 1999 THA patients and 1375 TKA patients. In the THA cohort, 1636 (82%) were Caucasian, 177 (9%) were African-American, and 186 (9%) were of other races. In the TKA cohort, 864 (63%) were Caucasian, 236 (17%) were African-American, and 275 (20%) were of other races. Surgical-time significantly differed between the groups that underwent THA (88.4vs.100.5vs.96.1; p < 0.001) with African-Americans requiring the longest operative time. Length-of-stay significantly differed in both THA (1.5vs.1.9vs.1.8; p < 0.001) and TKA (2.1vs.2.5vs.2.3; p < 0.001) cohorts, with African-Americans having the longest stay. Caucasians reported significantly higher PROM scores compared to non-Caucasians in both cohorts. All-cause emergency-department (ED) visits, 90-day postoperative events (readmissions&revisions), and discharge-disposition did not statistically differ in both cohorts.

CONCLUSION

Non-Caucasian patients demonstrated lower PROM scores when compared to Caucasian patients following TJA although the differences may not be clinically relevant. LOS was significantly longer for African-Americans in both THA and TKA cohorts. Further investigation identifying racial disparity interventions is warranted.

LEVEL OF EVIDENCE

Prognostic Level III.

Factors Affecting Hospital Length of Stay following Total Knee Replacement: A Retrospective Analysis in a Regional Hospital

In an effort to reduce hospital length of stay (LoS) following total knee arthroplasty (TKA), patient management strategies have evolved over time. The aims of this study were threefold: first, to quantify the reduction in LoS for TKA in a regional hospital; second, to identify the patient, surgical and management factors associated with hospital LoS; and lastly, to assess the change in complications incidence and hospital readmission as a function of LoS. A retrospective chart review was conducted on a consecutive series of primary and revision TKAs from January 2012 to March 2018. Factors describing patient demographics, as well as preoperative, intraoperative, surgical, and postoperative management, were extracted from paper and electronic medical records by a team of reviewers. Multivariate linear regression was performed to assess the association between these factors and LoS. In total, 362 procedures were included, which were reduced to 329 admissions once simultaneous bilateral procedures were taken into account. Median LoS reduced significantly (p = 0.001) from 6 to 2 days over the period of review. A stepwise regression analysis identified patient characteristics (age, gender, comorbidities, discharge barriers), perioperative management (anesthesia type), surgical characteristics (approach, alignment method), and postoperative management (mobilization timing, postoperative narcotic use, complication prior to discharge) as factors explaining 58.3% of the variance in LoS. Representation to emergency (6%) and hospital readmission (3%) remained low for the reviewed period. Efforts to reduce hospital LoS following TKA within a regional hospital setting can be achieved over time without significant increases in the rate or severity of complications or representation to acute care and subsequent readmission. The findings establish the role of patient, surgical and management factors in the context of agreed discharge criteria between care providers.

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.

Smoking, unemployment, female sex, obesity, and medication use yield worse outcomes in patellofemoral arthroplasty

PURPOSE

The purpose of this study was to identify effects of psychosocial and demographic factors on patellofemoral arthroplasty (PFA) outcomes.

METHODS

Patients who underwent PFA by a single surgeon between 2002 and 2013 (min. 2 year follow-up) were included. Knee Society scores (KSS), UCLA, and Tegner Scores were prospectively collected in a designated arthroplasty registry. Patient records were retrospectively reviewed and univariate and multivariate statistical analyses were performed to assess the effect of psychosocial factors and demographic variables including patient sex, BMI, smoking and medication use, psychiatric history, and employment status on improvement between pre- and post-operative scores.

RESULTS

Seventy-four knees in 55 patients (88% female) with a mean age of 51.8 (SD 8.8) and mean follow-up of 46.5 (SD 26.9) months were included. Patients showed significant improvement in all functional outcomes (p < 0.001). Mean improvement in KSS-F scores and median improvement in Tegner scores was greater in males compared to females (37.8 vs 16.1, p = 0.007; 3.0 vs 2.0, p = 0.07, respectively). Smokers showed less improvement in KSS-P compared to non-smokers (17.2 vs 30.0, p = 0.028). Retired or employed patients had a greater mean improvement in KSS-F and median improvement in Tegner Scores compared to those were unemployed or on work disability (p = 0.022, p = 0.01). Patients who reported using opioids and/or anti-depressants pre-operatively showed less improvement in UCLA scores (p = 0.006). Obese patients showed less improvement in both KSS-F and Tegner score compared to non-obese patients (p = 0.009, p = 0.004).

CONCLUSION

Psychosocial factors influence the degree of improvement following PFA. Although patients showed overall improvement compared to their baseline scores, obese patients, smokers, unemployed/work disabled, and pre-operative use of opioids and/or anti-depressants were risk factors for decreased improvement… The consideration of psychosocial variables are clinically important when assessing a patient's candidacy for PFA and improve pre-operative patient selection and counselling.

LEVEL OF EVIDENCE

Level IV.

Patient outcomes after total hip arthroplasty in extreme elderly patients older than 80 years

BACKGROUND

While extreme elderly patients (age 80 and above) benefit from joint replacement, there is controversy about whether their physical function improves as much as younger individuals following total hip arthroplasty.

METHODS

We completed a retrospective cohort study comparing extreme elderly total hip arthroplasty (THA) patients to younger patients. We obtained data from a large institutional repository of 2327 consecutive THAs performed from April 2011 through July 2016 at an American academic medical centre. We performed multivariate regression analyses to determine associations between age group and clinically significant improvement in the Patient-Reported Outcome Measurement Information System (PROMIS)-10 physical component summary (PCS) score. Secondary outcomes included the magnitude of PCS change, length of stay (LOS), and facility discharge.

RESULTS

There were 187 THAs (8.0%) in patients age ⩾ 80 years compared to 2140 THA procedures in patients < age 80. Extreme elderly patients had similar adjusted odds of achieving clinically significant PCS improvement after THA (p = 0.528) and there were no statistical differences in adjusted postoperative PCS score improvements between the cohorts. Extreme elderly patients were associated with a 0.68 day longer adjusted LOS (p < 0.001) and demonstrated higher adjusted odds of facility discharge following THA (OR 8.96, p < 0.001).

CONCLUSIONS

Compared to younger patients, extreme elderly individuals had similar adjusted postoperative functional outcomes following THA but utilised substantially more resources in the form of increased time in the hospital and higher rates of facility discharges.

Development and Validation of a Model for Predicting Rehabilitation Care Location Among Patients Discharged Home After Total Knee Arthroplasty

BACKGROUND

Demand for joint replacement is increasing, with many patients receiving postsurgical physical therapy (PT) in non-inpatient settings. Clinicians need a reliable tool to guide decisions about the appropriate PT setting for patients discharged home after surgery. We developed and validated a model to predict PT location for patients in our health system discharged home after total knee arthroplasty.

METHODS

We analyzed data for patients who completed a preoperative total knee risk assessment in 2017 (model development cohort) or during the first 6 months of 2018 (model validation cohort). The initial total knee risk assessment, to guide rehabilitation disposition, included 28 variables in mobility, social, and environment domains, and on patient demographics and comorbidities. Multivariable logistic regression was used to identify factors that best predict discharge to home health service (HHS) vs home with outpatient PT. Model performance was assessed by standard criteria.

RESULTS

The development cohort included 259 patients (19%) discharged to HHS and 1129 patients (81%) discharged to home with outpatient PT. The validation cohort included 609 patients, with 91 (15%) discharged to HHS. The final model included age, gender, motivation for outpatient PT, and reliable transportation. Patients without motivation for outpatient PT had the highest probability of discharge to HHS, followed by those without reliable transportation. Model performance was excellent in the development and validation cohort, with c-statistics of 0.91 and 0.86, respectively.

CONCLUSION

We developed and validated a predictive model for total knee arthroplasty PT discharge location. This model includes 4 variables with accurate prediction to guide patient-clinician preoperative decision making.

Do Medicare's Patient-Reported Outcome Measures Collection Windows Accurately Reflect Academic Clinical Practice?

BACKGROUND

The Comprehensive Care for Joint Replacement (CJR) mandates collection of patient-reported outcome measures (PROMs) for eligible total hip and total knee arthroplasty (THA and TKA) procedures during specific time periods that may not be attainable within routine academic practice.

METHODS

We performed a retrospective analysis of prospectively collected PROM data from a 2017 cohort of primary THA and TKA patients who completed the Patient-Reported Outcomes Measurement Information System-10 global health survey in preoperative or postoperative time periods. The primary outcome was completion rates of Patient-Reported Outcomes Measurement Information System-10 per the CJR collection periods (90-0 days preoperative and 270-365 days postoperative) compared to an extended postoperative collection period of 270-396 days. Bivariate analysis and logistic regression were used to analyze the association between survey completion rates and patient characteristics.

RESULTS

Of the 860 primary THAs and TKAs in 2017, 725 (84.3%) had preoperative surveys completed 90-0 days before surgery. Among the 725 patients, 215 (29.7%) completed postoperative surveys within the CJR timeline of 270-365 days. Completion increased by 120 additional surveys (+16.5%) in the additional postoperative time period of 270-396 days (P < .001). No patient or procedural factors significantly correlated with a higher likelihood of postoperative PROM completion (P > .05 for all covariates).

CONCLUSION

In an academic clinical practice, completion rates of postoperative PROMs as part of routine clinical practice within the CJR mandated period was low for THA and TKA patients. CJR may consider additional time beyond 365 days to improve PROM completion rates.

Effect modifiers for patient-reported outcomes in operatively and nonoperatively treated patients with adult symptomatic lumbar scoliosis: a combined analysis of randomized and observational cohorts

OBJECTIVE

Adult symptomatic lumbar scoliosis (ASLS) is a common and disabling condition. The ASLS-1 was a multicenter, dual-arm study (with randomized and observational cohorts) examining operative and nonoperative care on health-related quality of life in ASLS. An aim of ASLS-1 was to determine patient and radiographic factors that modify the effect of operative treatment for ASLS.

METHODS

Patients 40-80 years old with ASLS were enrolled in randomized and observational cohorts at 9 North American centers. Primary outcomes were the differences in mean change from baseline to 2-year follow-up for the SRS-22 subscore (SRS-SS) and the Oswestry Disability Index (ODI). Analyses were performed using an as-treated approach with combined cohorts. Factors examined were prespecified or determined using regression tree analysis. For each potential effect modifier, subgroups were created using clinically relevant cutoffs or via regression trees. Estimates of within-group and between-group change were compared using generalized linear mixed models. An effect modifier was defined as a treatment effect difference greater than the minimal detectable measurement difference for both SRS-SS (0.4) and ODI (7).

RESULTS

Two hundred eighty-six patients were enrolled and 256 (90%) completed 2-year follow-up; 171 received operative treatment and 115 received nonoperative treatment. Surgery was superior to nonoperative care for all effect subgroups considered, with the exception of those with nearly normal pelvic incidence-lumbar lordosis (PI-LL) match (≤ 11°). Male patients and patients with more (> 11°) PI-LL mismatch at baseline had greater operative treatment effects on both the SRS-SS and ODI compared to nonoperative treatment. No other radiographic subgroups were associated with treatment effects. High BMI, lower socioeconomic status, and poor mental health were not related to worse outcomes.

CONCLUSIONS

Numerous factors previously related to poor outcomes with surgery, such as low mental health, lower socioeconomic status, and high BMI, were not related to outcomes in ASLS in this exploratory analysis. Those patients with higher PI-LL mismatch did improve more with surgery than those with normal alignment. On average, none of the factors considered were associated with a worse outcome with operative treatment versus nonoperative treatment. These findings may guide future prospective analyses of factors related to outcomes in ASLS care.

Preoperative Patient Factors Affecting Length of Stay following Total Knee Arthroplasty: A Systematic Review and Meta-Analysis

BACKGROUND

Total knee arthroplasty (TKA) yields substantial improvements in quality of life for patients with severe osteoarthritis. Previous research has shown that TKA outcomes are inferior in patients with certain demographic and clinical factors. Length of stay (LOS) following TKA is a major component of costs incurred by healthcare providers. It is hypothesized that patient-related factors may influence LOS following TKA. The purpose of this systematic review and meta-analysis is to investigate these factors.

METHODS

Three databases (PubMed, Embase, and OVID Medline) were searched using variants of the terms "total knee arthroplasty" and "length of stay". Studies were screened and data abstracted in duplicate. The primary outcome was the effect of prognostic variables on LOS following TKA. Meta-analysis was performed using the Review Manager (RevMan) software (version 5.3. Copenhagen: The Nordic Cochrane Center, The Cochrane Collaboration, 2014).

RESULTS

A total of 68 studies met all inclusion criteria for this review. These studies comprised 21,494,459 patients undergoing TKA with mean age 66.82 years (range, 15-95 years) and 63.8% (12,165,160 of 19,060,572 reported) females. The mean MINORS score was 7, suggesting that studies had a low quality of evidence. Mean LOS following TKA has steadily decreased over the past 4 decades, partially because of the implementation of fast-track programs. Demographic factors associated with increased LOS were age >70 years (mean difference [MD] = 0.81; 95% confidence interval [CI] = 0.38-1.24), female gender (MD = 0.32; 95% CI = 0.29-0.48), body mass index >30 (MD = 0.09; 95% CI = 0.01-0.16), and non-White race (MD = 0.20; 95% CI = 0.10-0.29). Clinical factors associated with increased LOS were American Society of Anesthesiologists score 3-4 vs 1-2 (MD = 1.12; 95% CI = 0.58 to 1.66), Charlson Comorbidity Index > 0 vs 0 (MD = 0.77; 95% CI = 0.32 to 1.22), and preoperative hemoglobin < 130 g/L (MD = 0.66; 95% CI = 0.34 to 0.98).

CONCLUSION

This systematic review and meta-analysis showed that increased age, female gender, body mass index ≥ 30, non-White race, American Society of Anesthesiologists > 2, Charlson Comorbidity Index > 0, and preoperative hemoglobin < 130 g/L were predictors of increased LOS. Mean LOS has steadily decreased over the past decades with the implementation of perioperative "fast-track" programs. Future research should investigate the benefits of preoperative risk factor modification on LOS, in addition to novel surgical approaches, anesthetic adjuvants, and physiotherapy modifications.

LEVEL OF EVIDENCE

IV, systematic review, and meta-analysis of level III and IV evidence.

Preoperative Weight Loss for Morbidly Obese Patients Undergoing Total Knee Arthroplasty: Determining the Necessary Amount

BACKGROUND

Many surgeons require or request weight loss among morbidly obese patients (those with a body mass index [BMI] of ≥40 kg/m) before undergoing total knee arthroplasty. We sought to determine how much weight reduction was necessary to improve operative time, length of stay, discharge to a facility, and physical function improvement.

METHODS

Using a retrospective review of cohort data that were prospectively collected from 2011 to 2016 at 1 tertiary institution, we identified 203 patients who were morbidly obese at least 90 days before the surgical procedure and had their BMI measured again at the immediate preoperative visit. All heights and weights were clinically measured. We used logistic and linear regression models that adjusted for preoperative age, sex, year of the surgical procedure, bilateral status, physical function (Patient-Reported Outcomes Measurement Information System [PROMIS]-10 physical component score [PCS]), mental function (PROMIS-10 mental component score [MCS]), and the Charlson Comorbidity Index.

RESULTS

Of the 203 patients in the study, 41% lost at least 5 pounds (2.27 kg) before the surgical procedure, 29% lost at least 10 pounds (4.54 kg), and 14% lost at least 20 pounds (9.07 kg). Among morbidly obese patients, losing 20 pounds before a total knee arthroplasty was associated with lower adjusted odds of discharge to a facility (odds ratio [OR], 0.28 [95% confidence interval (CI), 0.09 to 0.94]; p = 0.039), lower odds of extended length of stay of at least 4 days (OR, 0.24 [95% CI, 0.07 to 0.88]; p = 0.031), and an absolute shorter length of stay (mean difference, -0.87 day [95% CI, -1.39 to -0.36 days]; p = 0.001). There were no differences in operative time or PCS improvement. Losing 5 or 10 pounds was not associated with differences in any outcome.

CONCLUSIONS

Losing at least 20 pounds before total knee arthroplasty was associated with shorter length of stay and lower odds of facility discharge for morbidly obese patients, even while most patients remained morbidly or severely obese. Although there were no differences in operative time or physical function improvement, this has considerable implications for patient burden and cost reduction. Patients and providers may want to focus on larger preoperative weight loss targets.

LEVEL OF EVIDENCE

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

Relationship Between Baseline Patient-reported Outcomes and Demographic, Psychosocial, and Clinical Characteristics: A Retrospective Study

Introduction

Alternative payment models in total lower extremity joint replacement (TJR) increasingly emphasize patient-reported outcomes (PROs) to link the latter to value-based payments. It is unclear to what extent demographic, psychosocial, and clinical characteristics are related to PROs measured preoperatively with the commonly used Hip/Knee Osteoarthritis Outcome Scores (HOOS/KOOS) and the Veterans RAND 12-Item Health Survey (VR-12) questionnaires. We aim to identify (1) the preoperative relationship between HOOS/KOOS and VR-12 scores and several demographic, psychosocial, and clinical patient characteristics and (2) the best modifiable factors for optimization, which may result in improved baseline PROs before TJR.

Methods

All TJR cases performed in 2017 at the two highest-volume hospitals within an urban academic health system were queried. Preoperative HOOS/KOOS and VR-12 surveys were administered through an e-collection platform. VR-12 physical and mental component scores (PCS, MCS) were generated. Patient information was extracted from the electronic health record. Bivariate and multivariate regression analyses were performed. Odds ratios (ORs) and 95% confidence intervals were reported.

Results

In univariate analysis, patients with HOOS/KOOS, VR-12 PCS, and MCS in the ≤25th percentile group were more likely to have an ASA score of ≥3 compared with those with higher scores. In multivariate analysis, increased and decreased odds of low HOOS/KOOS were associated with a one-unit increase in Charlson Comorbidity Index (OR, 1.16) and VR-12 MCS (OR, 0.97), respectively. Increased odds of low baseline VR-12 PCS and MCS were associated with ASA class ≥3 (OR, 1.65 and 1.40). Decreased odds of a low MCS were associated with an increase in HOOS/KOOS (OR, 0.98) (P ≤ 0.05 for all).

Conclusion

Of the factors that are associated with low baseline PRO scores, preoperatively addressing mismanaged comorbidities, mental health, and physical function were identified as the best modifiable factors for optimization, which may result in improved baseline PROs before TJR.

Short term patient outcomes after total knee arthroplasty: Does the implant matter?

BACKGROUND

Newer implants for total knee arthroplasty (TKA) often gain market share at higher cost with little patient-reported and long-term clinical data. We compared outcomes after TKA using two different implants: DePuy PFC Sigma and Attune.

METHODS

Using a prospective data repository from an academic tertiary medical center, we analyzed 2116 TKAs (1603 Sigma and 513 Attune) from April 2011 through July 2016. Outcomes included length of surgery, length of stay, facility discharge, 90-day reoperation, range of motion (ROM) change, and patient-reported physical function (PCS).

RESULTS

There was no difference in length of surgery (Attune -2.87 min, P = 0.143). Implant type was not associated with extended LOS (>3 days) (OR 0.80, P = 0.439). There was no difference in facility discharge (OR 0.65, P = 0.103). Unadjusted 90-day reoperations were 0.3% for Sigma and 1.0% for Attune cohorts (P = 0.158). Sigma implants were associated with more ROM improvement in unadjusted analyses (+2.1 degree improvement P = 0.031). Fifty nine percent of the Sigma cohort and 49% of the Attune cohort achieved the minimal clinically important (MCID) change for PCS improvement, although there was no adjusted difference in achieving MCID (Attune OR 0.84, P = 0.435). There was no adjusted difference in absolute PCS improvement (Attune +0.12 score, P = 0.864).

CONCLUSIONS

Our data show no difference in physical function and most outcomes between Sigma and Attune. Attune implants had shorter absolute LOS, but there were no differences in extended LOS.

Patient Outcomes After Total Knee Arthroplasty in Patients Older Than 80 Years

BACKGROUND

Patients aged 80 and above who suffer from end-stage osteoarthritis may benefit from total knee arthroplasty (TKA), but at high potential risk. Additionally, there is controversy about whether functional improvement in patients above age 80 is similar to younger patients. We compared functional improvement, length of stay (LOS), and facility discharge rates after TKA between this cohort and patients less than 80 years of age.

METHODS

We completed a retrospective cohort study comparing TKA patients aged 80 and above with all patients younger than 80. We utilized data from a prospectively collected institutional repository of 2308 TKAs performed from April 2011 through July 2016 at an academic medical center in the United States. We performed multivariable logistic regression to determine the association between age group and clinically significant improvement in the Patient-Reported Outcome Measurement Information System (PROMIS)-10 physical component summary (PCS) score. Secondary outcomes included the magnitude of PCS change, LOS, and facility discharge.

RESULTS

There were 175 (7.6%) TKAs in patients older than 80 years compared with 2133 TKAs in patients younger than 80. Patients over 80 had similar adjusted odds of achieving clinically significant PCS improvement following TKA (P = .366), and there was no statistical difference in adjusted postoperative PCS improvement between the 2 age groups. Age 80 and above was associated with a longer adjusted LOS and demonstrated increased odds of facility discharge (odds ratio 4.11, P < .001) after TKA.

CONCLUSION

Following TKA, patients older than 80 years demonstrate similar adjusted functional improvement in comparison to younger patients. However, older patients did require substantially more resources as they remained in the hospital longer and were discharged to rehabilitation more often.

Resident Participation is Not Associated With Worse Outcomes After TKA

BACKGROUND

Approximately one-half of all US surgical procedures, and one-third of orthopaedic procedures, are performed at teaching hospitals. However, the effect of resident participation and their level of training on patient care for TKA postoperative physical function, operative time, length of stay, and facility discharge are unclear.

QUESTIONS/PURPOSES

(1) Are resident participation, postgraduate year (PGY) training level, and number of residents associated with absolute postoperative Patient-Reported Outcomes Measurement Information System (PROMIS®-10) global physical function score (PCS), and achieving minimum clinically important difference (MCID) PCS improvement, after TKA? (2) Are resident participation, PGY, and number of residents associated with increased TKA operative time? (3) Are resident participation, PGY, and number of residents associated with increased length of stay after TKA? (4) Are resident participation, PGY, and number of residents associated with higher odds of patients being discharged to another inpatient facility, rather than to their home (facility discharge)?

METHODS

We performed a retrospective study using a longitudinally maintained institutional registry of TKAs that included 1626 patients at a single tertiary academic institution from April 2011 through July 2016. All patients who underwent primary, elective unilateral TKA were included with no exclusions. All patients were included in the operative time, length of stay, and facility discharge models. The PCS model required postoperative PCS score (n = 1417; 87%; mean, 46.4; SD, 8.5) and the MCID PCS model required pre- and postoperative PCS (n = 1333; 82%; 55% achieved MCID). Resident participation was defined as named residents being present in the operating room and documented in the operative notes, and resident PGY level was determined by the date of TKA and its duration since the resident entered the program and using the standard resident academic calendar (July - June). Multivariable regression was used to assess PCS scores, operative time, length of stay, and facility discharge in patients whose surgery was performed with and without intraoperative resident participation, accounting for PGY training level and number of residents. We defined the MCID PCS score improvement as 5 points on a 100-point scale. Adjusting variables included surgeon, academic year, age, sex, race-ethnicity, Charlson Comorbidity Index, preoperative PCS, and patient-reported mental function, BMI, tobacco use, alcohol use, and postoperative PCS time for the PCS models. We had postoperative PCS for 1417 (87%) surgeries.

RESULTS

Compared with attending-only TKAs (5% of procedures), no postgraduate year or number of residents was associated with either postoperative PCS or MCID PCS improvement (PCS: PGY-1 = -0.98, 95% CI, -6.14 to 4.17, p = 0.708; PGY-2 = -0.26, 95% CI, -2.01to 1.49, p = 0.768; PGY-3 = -0.32, 95% CI, -2.16 to 1.51, p = 0.730; PGY-4 = -0.28, 95% CI, -1.99 to 1.43, p = 0.746; PGY-5 = -0.47, 95% CI, -2.13 to 1.18, p = 0.575; two residents = 0.28, 95% CI, -1.05 to 1.62, p = 0.677) (MCID PCS: PGY-1 = odds ratio [OR], 0.30, 95% CI, 0.07-1.30, p = 0.108; PGY-2 = OR, 0.86, 95% CI, 0.46-1.62, p = 0.641; PGY-3 = OR, 0.97, 95% CI, 0.49-1.89, p = 0.921; PGY-4 = OR, 0.73, 95% CI, 0.39-1.36, p = 0.325; PGY-5 = OR, 0.71, 95% CI, 0.39-1.29, p = 0.259; two residents = OR, 1.23, 95% CI, 0.80-1.89, p = 0.337). Longer operative times were associated with all PGY levels except for PGY-5 (attending surgeon only [reference] = 85.60 minutes, SD, 14.5 minutes; PGY-1 = 100. 13 minutes, SD, 21.22 minutes, +8.44 minutes, p = 0.015; PGY-2 = 103.40 minutes, SD, 23.01 minutes, +11.63 minutes, p < 0.001; PGY-3 = 97.82 minutes, SD, 18.24 minutes, +9.68 minutes, p < 0.001; PGY-4 = 96.39 minutes, SD, 18.94 minutes, +4.19 minutes, p = 0.011; PGY-5 = 88.91 minutes, SD, 19.81 minutes, -0.29 minutes, p = 0.853) or the presence of multiple residents (+4.39 minutes, p = 0.024). There were no associations with length of stay (PGY-1 = +0.04 days, 95% CI, -0.63 to 0.71 days, p = 0.912; PGY-2 = -0.08 days, 95% CI, -0.48 to 0.33 days, p = 0.711; PGY-3 = -0.29 days, 95% CI, -0.66 to 0.09 days, p = 0.131; PGY-4 = -0.30 days, 95% CI, -0.69 to 0.08 days, p = 0.120; PGY-5 = -0.28 days, 95% CI, -0.66 to 0.10 days, p = 0.145; two residents = -0.12 days, 95% CI, -0.29 to 0.06 days, p = 0.196) or facility discharge (PGY-1 = OR, 1.03, 95% CI, 0.26-4.08, p = 0.970; PGY-2 = OR, 0.61, 95% CI, 0.31-1.20, p = 0.154; PGY-3 = OR, 0.98, 95% CI, 0.48-2.02, p = 0.964; PGY-4 = OR, 0.83, 95% CI, 0.43-1.57, p = 0.599; PGY-5 = OR, 0.7, 95% CI, 0.41-1.40, p = 0.372; two residents = OR, 0.93, 95% CI, 0.56-1.54, p = 0.766) for any PGY or number of residents.

CONCLUSIONS

Our findings should help assure patients, residents, physicians, insurers, and hospital administrators that resident participation, after adjusting for numerous patient and clinical factors, does not have any association with key medical and financial metrics, including postoperative PCS, MCID PCS, length of stay, and facility discharge. Future research in this field should focus on whether residents affect knee-specific patient-reported outcomes such as the Knee Injury and Osteoarthritis Score and additional orthopaedic procedures, and determine how resident medical education can be further enhanced without compromising patient care and safety.Level of Evidence Level III, therapeutic study.