Utilization of Total Joint Arthroplasty by Rural-Urban Designation in Patients With Osteoarthritis in a Universal Coverage System.

BACKGROUND: Utilization of total joint arthroplasty (TJA) is affected by differences linked to sex, race, and socioeconomic status; there is little information about how geographic variation contributes to these differences. We sought to determine whether discrepancies in TJA utilization exist in patients diagnosed with osteoarthritis (OA) based upon urban-rural designation in a universal coverage system. METHODS: We conducted a cohort study using data from a US-integrated healthcare system (2015 to 2019). Patients aged ≥50 years who had a diagnosis of hip or knee OA were included. Total hip arthroplasty and total knee arthroplasty utilization (in respective OA cohorts) was evaluated by urban-rural designation (urban, mid, and rural). Incidence rate ratios (IRRs) for urban-rural regions were modeled using multivariable Poisson regressions. RESULTS: The study cohort included 93,642 patients who have hip OA and 275,967 patients who had knee OA. In adjusted analysis, utilization of primary total hip arthroplasty was lower in patients living in urban areas (IRR = 0.87, 95% confidence interval = 0.81 to 0.94) compared to patients in rural regions. Similarly, total knee arthroplasty was used at a lower rate in urban areas (IRR = 0.88, 95% confidence interval = 0.82 to 0.95) compared with rural regions. We found no differences in the hip and knee groups within the mid-region. CONCLUSIONS: In hip and knee OA patients enrolled in a universal coverage system, we found patients living in urban areas had lower TJA utilization compared to patients living in rural areas. Further research is needed to determine how patient location contributes to differences in elective TJA utilization. LEVEL OF EVIDENCE: III.

Temporal Trends in Deep Surgical Site Infections After Six Orthopaedic Procedures Over a 12-year Period Within a US-based Healthcare System.

INTRODUCTION: Centers of excellence and bundled payment models have driven perioperative optimization and surgical site infection (SSI) prevention with decolonization protocols and antibiotic prophylaxis strategies. We sought to evaluate time trends in the incidence of deep SSI and its causative organisms after six orthopaedic procedures in a US-based integrated healthcare system. METHODS: We conducted a population-level time-trend study using data from Kaiser Permanente's orthopaedic registries. All patients who underwent primary anterior cruciate ligament reconstruction (ACLR), total knee arthroplasty (TKA), elective total hip arthroplasty (THA), hip fracture repair, shoulder arthroplasty, and spine surgery were identified (2009 to 2020). The annual incidence of 90-day deep SSI was identified according to the National Healthcare Safety Network/Centers for Disease Control and Prevention guidelines with manual chart validation for identified infections. Poisson regression was used to evaluate annual trends in SSI incidence with surgical year as the exposure of interest. Annual trends in overall incidence and organism-specific incidence were considered. RESULTS: The final study sample was composed of 465,797 primary orthopaedic procedures. Over the 12-year study period, a decreasing trend in deep SSI was observed for ACLR and hip fracture repair. Although there was variation in incidence rates for specific operative years for TKA, elective THA, shoulder arthroplasty, and spine surgery, no consistent decreasing trends over time were found. Decreasing rates of Staphylococcus aureus infections over time after hip fracture repair, shoulder arthroplasty, and spine surgery and decreasing trends in antibiotic resistance after elective THA and spine surgery were also observed. Increasing trends of polymicrobial infections were observed after TKA and Cutibacterium acnes after elective THA. CONCLUSIONS: The overall incidence of deep SSI after six orthopaedic procedures was rare. Decreasing SSI rates were observed for ACLR and hip fracture repair within our US-based healthcare system. Polymicrobial infections after TKA and Cutibacterium acnes after elective THA warrant closer surveillance. LEVEL OF EVIDENCE: IV.

Association Between Race/Ethnicity and Total Joint Arthroplasty Utilization in a Universally Insured Population.

INTRODUCTION: Previous studies have documented racial and ethnic disparities in total joint arthroplasty (TJA) utilization in the United States. A potential mediator of healthcare disparities is unequal access to care, and studies have suggested that disparities may be ameliorated in systems of universal access. The purpose of this study was to assess whether racial/ethnic disparities in TJA utilization persist in a universally insured population of patients enrolled in a managed healthcare system. METHODS: This retrospective cohort study used data from a US integrated healthcare system (2015 to 2019). Patients aged 50 years and older with a diagnosis of hip or knee osteoarthritis were included. The outcome of interest was utilization of primary total hip arthroplasty and/or total knee arthroplasty, and the exposure of interest was race/ethnicity. Incidence rate ratios (IRRs) were modeled using multivariable Poisson regression controlling for confounders. RESULTS: There were 99,548 patients in the hip analysis and 290,324 in the knee analysis. Overall, 10.2% of the patients were Black, 20.5% were Hispanic, 9.6% were Asian, and 59.7% were White. In the multivariable analysis, utilization of primary total hip arthroplasty was significantly lower for all minority groups including Black (IRR, 0.55, 95% confidence interval [CI], 0.52-0.57, P < 0.0001), Hispanic (IRR, 0.63, 95% CI, 0.60-0.66, P < 0.0001), and Asian (IRR, 0.64, 95% CI, 0.61-0.68, P < 0.0001). Similarly, utilization of primary total knee arthroplasty was significantly lower for all minority groups including Black (IRR, 0.52, 95% CI, 0.49-0.54, P < 0.0001), Hispanic (IRR, 0.72, 95% CI, 0.70-0.75, P < 0.0001), and Asian (IRR, 0.60, 95% CI, 0.57-0.63, P < 0.0001) (all in comparison with White as reference). CONCLUSIONS: In this study of TJA utilization in a universally insured population of patients enrolled in a managed healthcare system, disparities on the basis of race and ethnicity persisted. Additional research is required to determine the reasons for this finding and to identify interventions which could ameliorate these disparities.

Modular Tibial Stem Use and Risk of Revision for Aseptic Loosening in Cemented Primary Total Knee Arthroplasty.

BACKGROUND: Modular tibial stem extensions in total knee arthroplasty (TKA) are designed to reduce the risk of aseptic loosening of the tibial base plate. However, these implants add significant cost and an evaluation of their effectiveness in reducing this risk of loosening has not been studied in a large cohort. We sought to evaluate modular tibial stem utilization in primary TKA. METHODS: We conducted a cohort study using our integrated healthcare system's Total Joint Replacement Registry. Patients who underwent cemented primary TKA were identified (2009-2019). Propensity scores were used to 1:1 match patients without to those with a stem extension. Cox proportional-hazards regression was used to evaluate the risk for revision due to aseptic loosening. RESULTS: Ten thousand four hundred seventy six TKA with a modular tibial stem were matched to 10,476 TKA without a tibial stem. Stem utilization associated with a lower risk of revision for loosening across all postoperative follow-up (hazard ratio = 0.38, 95% confidence interval = 0.17-0.85). CONCLUSION: In a matched cohort study, we observed presence of a stem extension was associated with a lower risk of revision for aseptic loosening. Further study to identify specific risk factors for aseptic loosening and confirm the findings presented here are warranted. LEVEL OF EVIDENCE: Level III.

The Association of Race/Ethnicity and Total Knee Arthroplasty Outcomes in a Universally Insured Population.

BACKGROUND: Prior studies have documented racial/ethnic disparities in the United States for total knee arthroplasty (TKA) outcomes. One factor cited as a potential mediator is unequal access to care. We sought to assess whether racial/ethnic disparities persist in a universally insured TKA population. METHODS: A US integrated health system's total joint replacement registry was used to identify elective primary TKA (2000-2016). Racial/ethnic differences in revision and 90-day postoperative events (readmission, emergency department [ED] visit, infection, venous thromboembolism, and mortality) were analyzed using Cox proportional hazard and logistic regression with adjustment for confounders. RESULTS: Of 129,402 TKA, 68.8% were white, 16.2% were Hispanic, 8.4% were black, and 6.6% were Asian. Compared to white patients, Hispanic patients had lower risks of septic revision (hazard ratio [HR] = 0.69, 95% confidence interval [CI] = 0.57-0.83) and infection (odds ratio [OR] = 0.42, 95% CI = 0.30-0.59), but a higher likelihood of ED visit (OR = 1.28, 95% CI = 1.22-1.34). Black patients had higher risks of aseptic revision (HR = 1.61, 95% CI = 1.42-1.83), readmission (OR = 1.13, 95% CI = 1.02-1.24), and ED visit (OR = 1.31, 95% CI = 1.23-1.39). Asian patients had lower risks of aseptic revision (HR = 0.67, 95% CI = 0.54-0.83), septic revision (HR = 0.78, 95% CI = 0.60-0.99), readmission (OR = 0.89, 95% CI = 0.79-1.00), and venous thromboembolism (OR = 0.59, 95% CI = 0.45-0.78). CONCLUSION: We observed differences in TKA outcome, even within a universally insured population. While lower risks in some outcomes were observed for Asian and Hispanic patients, the higher risks of aseptic revision and readmission for black patients and ED visit for black and Hispanic patients warrant further research to determine reasons for these findings to mitigate disparities. LEVEL OF EVIDENCE: Level III.

Lumbar Spine Fusion Patients See Similar Improvements in Physical Activity Level to Non-Spine Fusion Patients Following Total Hip Arthroplasty.

BACKGROUND: The impact of prior lumbar spinal fusion on the change in physical activity level following total hip arthroplasty (THA) has not been thoroughly examined. Therefore, we sought to compare the change in physical activity level following THA for patients with and without a history of lumbar spine fusion. METHODS: Patients who underwent primary elective THA were identified using an integrated healthcare system's Total Joint Replacement Registry (2010-2013). Prior lumbar spine fusion was identified using the healthcare system's Spine Registry. Physical activity was self-reported by patients and measured in min/wk. Generalized linear models were used to evaluate the association between prior spine fusion and the change in physical activity from 1 year pre-THA to 1-2 years post-THA. RESULTS: Of 11,416 THAs, 90 (0.8%) had a history of lumbar spinal fusion. Patients with a prior lumbar fusion had a median physical activity level of 28 min/wk prior to THA compared to 45 min/wk in the patients with no history of lumbar spinal fusion. One year after THA, patients with a history of lumbar spinal fusion reported a median of 120 min/wk of physical activity compared to 150 min/wk for patients without a history of lumbar spinal fusion. The difference in physical activity level change between groups was not statistically significant (estimate = -23.1, 95% confidence interval -62.1 to 15.9, P = .246). CONCLUSION: Patients with prior lumbar fusion were found to have lower self-reported physical activity levels than patients without spine fusion both before and after THA surgery. However, both groups saw the same degree of improvement in physical activity level following THA. These findings may help in counseling patients who have had a prior lumbar spine fusion and in setting appropriate expectations prior to THA.

Association of Race and Ethnicity with Total Hip Arthroplasty Outcomes in a Universally Insured Population.

BACKGROUND: Prior studies have documented racial and ethnic disparities in total hip arthroplasty (THA) outcomes in the U.S. The purpose of this study was to assess whether racial/ethnic disparities in THA outcomes persist in a universally insured population of patients enrolled in an integrated health-care system. METHODS: A U.S. health-care system total joint replacement registry was used to identify patients who underwent elective primary THA between 2001 and 2016. Data on patient demographics, surgical procedures, implant characteristics, and outcomes were obtained from the registry. The outcomes analyzed were lifetime revision (all-cause, aseptic, and septic) and 90-day postoperative events (infection, venous thromboembolism, emergency department [ED] visits, readmission, and mortality). Racial/ethnic differences in outcomes were analyzed with use of multiple regression with adjustment for socioeconomic status and other potential confounders. RESULTS: Of 72,755 patients in the study, 79.1% were white, 8.2% were black, 8.5% were Hispanic, and 4.2% were Asian. Compared with white patients, lifetime all-cause revision was lower for black (adjusted hazard ratio [HR], 0.79; 95% confidence interval [CI], 0.66 to 0.94; p = 0.007), Hispanic (adjusted HR, 0.73; 95% CI, 0.61 to 0.87; p = 0.002), and Asian (adjusted HR, 0.49; 95% CI, 0.37 to 0.66; p < 0.001) patients. Ninety-day ED visits were more common among black (adjusted odds ratio [OR], 1.15; 95% CI, 1.05 to 1.25; p = 0.002) and Hispanic patients (adjusted OR, 1.18; 95% CI, 1.08 to 1.28; p < 0.001). For all other postoperative events, minority patients had similar or lower rates compared with white patients. CONCLUSIONS: In contrast to prior research, we found that minority patients enrolled in a managed health-care system had rates of lifetime reoperation and 90-day postoperative events that were generally similar to or lower than those of white patients, findings that may be related to the equal access and/or standardized protocols associated with treatment in the managed care system. However, black and Hispanic patients still had higher rates of 90-day ED visits. Further research is required to determine the reasons for this finding and to identify interventions that could reduce unnecessary ED visits. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.