Racialized Inequities in Knee Arthroplasty Receipt After Osteoarthritis Diagnosis in the US Military Health System.

OBJECTIVE: The goal was to evaluate institutional inequities in the US Military Health System in knee arthroplasty receipt within three years of knee osteoarthritis diagnosis when accounting for other treatments received (eg, physical therapy, medications). METHODS: In this retrospective observational cohort study, medical record data of patients (n = 29,734) who received a primary osteoarthritis diagnosis in the US Military Health System between January 2016 and January 2020 were analyzed. Data included receipt of physical therapy one year before diagnosis and up to three years after diagnosis, prediagnosis opioid and nonopioid prescription receipt, health-related factors associated with levels of racism, and the primary outcome, knee arthroplasty receipt within three years after diagnosis. RESULTS: In a generalized additive model with time-varying covariates, Asian and Pacific Islander (incidence rate ratio [IRR] 0.58, 95% confidence interval [CI] 0.45-0.74), Black (IRR 0.52, 95%CI 0.46-0.59), and Latine (IRR 0.66, 95%CI 0.52-0.85) patients experienced racialized inequities in knee arthroplasty receipt, relative to white patients (all P < 0.001). CONCLUSIONS: In the present sample, Asian and Pacific Islander, Black, and Latine patients were significantly less likely to receive a knee arthroplasty, relative to white patients. Taken together, system-level resources are needed to identify and address mechanisms underlying institutional inequities in knee arthroplasty receipt, such as factors related to systemic and structural, institutional, and personally mediated racism.

Experiences with and perception of patient-reported outcome measurement in patients undergoing knee and hip replacement in Germany.

BACKGROUND: Patient-reported outcome measures - PROMs - have been developed to provide an assessment of patients' physical function, symptoms, and health-related quality of life. With patient-centered care becoming increasingly important, several national strategies have been initiated for PROM measurement. However, Germany is only at the beginning of this process. The objective of this study is to assess patients' experience with and perception of completing PROMs in patients undergoing knee and hip replacement in Germany. METHODS: This study used survey data from patients undergoing hip or knee replacement surgery in a hospital in Germany. Before surgery, patients completed a PROMs survey. After at least 6 months, patients were re-contacted to fill in a questionnaire about their experiences with and perception of the PROMs data collection. RESULTS: Most patients either agreed or totally agreed that the time to fill in the questionnaire was appropriate (89%), that the purpose of the PROMs collection was clear (85%), that the questionnaire's content applied to their appointment (73%), and that this systematic assessment was beneficial (81%). The corresponding proportions were 54% for feeling productive while waiting and 50% for feeling that the information in the questionnaire affected the patient-doctor interaction positively. Only few significant associations were found between patient characteristics and the favorability of patients' ratings. There were no significant differences between hip and knee replacement surgery patients regarding the favorability rating on any survey question. CONCLUSIONS: The results of this study suggest that PROMs collection in the context of hip and knee replacement surgery is practicable and partly also perceived beneficial by patients. Orthopedic procedures could serve as a starting point for broader use and routine PROMs collection in Germany.

Race Associated With Increased Complication Rates After Total Knee Arthroplasty.

BACKGROUND: Racial and ethnic disparities have been suggested to be associated with poor outcomes after total knee arthroplasty (TKA). While socioeconomic disadvantage has been studied, analyses of race as the primary variable are lacking. Therefore, we examined the potential differences between Black and White TKA recipients. Specifically, we assessed 30-day and 90-day, as well as 1 year: (1) emergency department visits and readmissions; (2) total complications; (3) as well as risk factors for total complications. METHODS: A consecutive series of 1,641 primary TKAs from January 2015 to December 2021 at a tertiary health care system were reviewed. Patients were stratified according to race, Black (n = 1,003) and White (n = 638). Outcomes of interest were analyzed using bivariate Chi-square and multivariate regressions. Demographic variables such as sex, American Society of Anesthesiologists classification, diabetes, congestive heart failure, chronic pulmonary disease, and socioeconomic status based on Area Deprivation Index were controlled for across all patients. RESULTS: The unadjusted analyses found that Black patients had an increased likelihood of 30-day emergency department visits and readmissions (P < .001). However, in the adjusted analyses, Black race was demonstrated to be a risk factor for increased total complications at all-time points (P ≤ .0279). Area Deprivation Index was not a risk for cumulative complications at these time points (P ≥ .2455). CONCLUSION: Black patients undergoing TKA may be at increased risk for complications with more risk factors including higher body mass index, tobacco use, substance abuse, chronic obstructive pulmonary disease, congestive heart failure, hypertension, chronic kidney disease, and diabetes and were thus, "sicker" initially than the White cohort. Surgeons are often treating these patients at the later stages of their diseases when risk factors are less modifiable, which necessitates a shift to early, preventable public health measures. While higher socioeconomic disadvantage has been associated with higher rates of complications, the results of this study suggest that race may play a greater role than previously thought.

The Effect of COVID-19 on Elective Total Knee Arthroplasty Utilization, Patient Comorbidity Burden, and Complications in the United States: A Nationwide Analysis.

INTRODUCTION: Total knee arthroplasty (TKA) is one of the highest volume elective procedures done nationwide. Elective surgery was suspended because of the COVID-19 pandemic. The utilization trends, comparison of patient demographics, and postoperative outcomes in 2020 have yet to be evaluated substantially. We compared temporal trends in procedural volume, patient demographics, and postoperative complications of elective TKA in 2019 and 2020. METHODS: Using a multicenter, nationwide representative sample, a retrospective query of the 2019 to 2020 American College of Surgeon's National Surgery Quality Improvement Program database was conducted for patients undergoing elective TKA. Temporal trends in utilization, demographics, and length of stay were compared pre-COVID-19 (2019 to 2020Q1) with post-COVID-19 (2020Q2 to Q4). Postoperative outcomes were compared by calendar year (2019 versus 2020). Linear regression was used to evaluate changes in procedural volume over time. A significance threshold of P < 0.05 was used. RESULTS: A total of 121,415 patients underwent elective TKA in 2019 (N = 72,002) and 2020 (N = 49,413), a 31.4% decline. The proportion of hospital-defined "outpatient" TKAs in 2020 was significantly greater than that in 2019 (41.5% versus 25.5%; P < 0.001). Elective TKA utilization declined by 65.1% in 2020Q2 and never returned to prepandemic baseline in 2020Q3 to Q4. The average length of stay was shorter in 2020 (1.56 versus 1.87 days; P < 0.001). The proportion of same-day discharge increased each quarter from 2019Q1 to Q4 (6.2% to 8.6%) to 2020Q1 to Q4 (8.7% to 17.1%). Total complication rates were similar in 2019 (4.84%) versus 2020 (4.75%); P = 0.430. The 30-day mortality (0.08% versus 0.07%; P = 0.858), revision surgery (1.0% versus 1.0%; P = 0.940), and readmission (2.8% versus 2.6%; P = 0.053) rates were no different between 2019 and 2020. CONCLUSION: Elective TKA declined during the second quarter of 2020. A large proportion of surgeries were transitioned to outpatient with rates of same-day discharge increasing over the study period, despite no change in complication, mortality, and readmission rates. Patient outcomes were not compromised despite pandemic restrictions for elective surgery. LEVEL OF EVIDENCE: Level III.

Practice Management Strategies Among Current Members of the American Association of Hip and Knee Surgeons.

BACKGROUND: A survey was conducted at the 2021 Annual Meeting of the American Association of Hip and Knee Surgeons (AAHKS) to evaluate current practice management strategies among AAHKS members. METHODS: An application was used by AAHKS members to answer both multiple-choice and yes or no questions. Specific questions were asked regarding the impact of COVID-19 pandemic on practice patterns. RESULTS: There was a dramatic acceleration in same day total joint arthroplasty with 85% of AAHKS members performing same day total joint arthroplasty. More AAHKS members remain in private practice (46%) than other practice types, whereas fee for service (34%) and relative value units (26%) are the major form of compensation. At the present time, 93% of practices are experiencing staffing shortages, and these shortages are having an impact on surgical volume. CONCLUSION: This survey elucidates the current practice patterns of AAHKS members. The pandemic has had a significant impact on some aspects of practice activity. Future surveys need to monitor changes in practice patterns over time.

Study on feasibility of the partial meniscal allograft transplantation.

Since the meniscus is an important stabilizing structure of the knee joint and has a significant role in load-bearing and shock absorption, so the complete structural and functional reconstructions of the teared menisci should be done not only after partial meniscectomy but also post total meniscectomy. So far, animal experiments and good clinical practice have showed that TMAT after total meniscectomy has partially solved the problem of structural and functional reconstructions after total meniscectomy. However, partial meniscectomy will also lead to accelerated knee degeneration, and its proportion is much higher than that of patients with total meniscectomy. Herein, the feasibility of PMAT after partial meniscectomy was investigated for the first time by using the 40% posterior horn meniscectomy model of the medial meniscus in Beagle dogs, and also for the first time, TMAT group and the total meniscectomy group were used as control groups. Compared with the TMAT, the transcriptomics evaluation, scanning electron microscope observation, histological regeneration and structure, biomechanical property, inflammation environment, and the knee function post PMAT were more similar to that of normal meniscus was first reported. This study provides a PMAT scheme with clinical translational value for the complete structural and functional reconstruction of the patients with partial meniscectomy and fills the gap in the field of teared meniscus therapy on the basis of quite well clinical applications of the meniscus repair and the TMAT.

Shape of the association between preoperative hemoglobin level and postoperative outcomes in patients undergoing primary arthroplasty.

BACKGROUND: The shape of the association between preoperative hemoglobin level and outcomes after primary arthroplasty has not been adequately described. This study aimed to characterize the association between preoperative hemoglobin level and important outcomes after primary hip and knee arthroplasty and how this association is influenced by other key confounders. METHODS: Using de-identified, population-based health administrative data for Ontario housed at ICES, we identified all primary hip and knee arthroplasty procedures performed in Ontario between April 2007 and March 2017. Preoperative hemoglobin level, age, sex, Charlson Comorbidity Index score, American Society of Anesthesiologists score, preadmission living status, Hospital-patient One-year Mortality Risk (HOMR) score, and serum sodium and creatinine levels were extracted. All relevant postoperative outcomes that could be measured accurately were identified. We performed multivariable logistic regression and restricted cubic splines analyses. RESULTS: A total of 188 176 patients clustered within 532 surgeons were studied. The adjusted likelihood of transfusion increased notably and progressively when the preoperative hemoglobin level was below 135 g/L; duration of surgery, patient age and HOMR score amplified this association. Risk of postoperative admission to critical care showed a linear association with preoperative hemoglobin level. Risks of unplanned 30-day emergency department visit, 30-day readmission and 1-year all-cause mortality showed curvilinear associations with baseline hemoglobin level, with risks being notably greater as the level deviated from 137 g/L to 141 g/L. CONCLUSION: Preoperative hemoglobin levels, both high and low, were independently significantly associated with primary arthroplasty outcomes, and levels at which outcome risks started to increase exceeded threshold values commonly used to define "normal." Preoperative hemoglobin level should be considered in future bundled payment models that aim to account for case-mix when grading postarthroplasty outcomes.

Comparing Postoperative Readmission Rates Between Veterans Receiving Total Knee Arthroplasty in the Veterans Health Administration Versus Community Care.

BACKGROUND: There are growing concerns that Veterans' increased use of Veterans Health Administration (VA)-purchased care in the community may lead to lower quality of care. OBJECTIVE: We compared rates of hospital readmissions following elective total knee arthroplasties (TKAs) that were either performed in VA or purchased by VA through community care (CC) at both the national and facility levels. METHODS: Three-year cohort study using VA and CC administrative data from the VA's Corporate Data Warehouse (October 1, 2016-September 30, 2019). We obtained Medicare data to capture readmissions that were paid by Medicare. We used the Centers for Medicare and Medicaid Services (CMS) methods to identify unplanned, 30-day, all-cause readmissions. A secondary outcome, TKA-related readmissions, identified readmissions resulting from complications of the index surgery. We ran mixed-effects logistic regression models to compare the risk-adjusted odds of all-cause and TKA-related readmissions between TKAs performed in VA versus CC, adjusting for patients' sociodemographic and clinical characteristics. PRINCIPAL FINDINGS: Nationally, the odds of experiencing an all-cause or TKA-related readmission were significantly lower for TKAs performed in VA versus CC (eg, the odds of experiencing an all-cause readmission in VA were 35% of those in CC. At the facility level, most VA facilities performed similarly to their corresponding CC providers, although there were 3 VA facilities that performed worse than their corresponding CC providers. CONCLUSIONS: Given VA's history in providing high-quality surgical care to Veterans, it is important to closely monitor and track whether the shift to CC for surgical care will impact quality in both settings over time.

Female reproductive factors and risk of joint replacement arthroplasty of the knee and hip due to osteoarthritis in postmenopausal women: a nationwide cohort study of 1.13 million women.

OBJECTIVES: Previous studies of the relationships between female reproductive factors and osteoarthritis (OA) have shown conflicting results. In this study, we aimed to explore the relationships between reproductive factors and joint replacement arthroplasty of the knee (TKRA) and hip (THRA) in a large nationwide population-based cohort of postmenopausal Korean women. METHODS: We included 1,134,680 subjects who participated in national health examinations in 2009 in the study. The study outcomes were incident THRA or TKRA due to severe hip or knee OA. The relationships between reproductive factors and THRA or TKRA were evaluated using a multivariable-adjusted proportional hazards model. RESULTS: During a mean follow-up duration of 8.2 years, 1,610 incident THRA cases and 60,670 incident TKRA cases were observed. Later age at menarche, longer breastfeeding, HRT and OC use were associated with increased risk of TKRA for severe knee OA, while later age at menopause and longer reproductive span were associated with decreased risk. With regard to THRA for severe hip OA, later menarche, longer breastfeeding, HRT more than 5 years, and OC use more than 1 year were associated with higher risk. The associations between reproductive factors and severe OA were more pronounced in underweight and younger subjects. CONCLUSION: We found that shorter estrogen exposure was associated with higher risk of TKRA due to severe knee OA, and such associations were more pronounced in underweight and younger subjects. The association between shorter estrogen exposure and THRA was not robust.

Costs of Joint Replacement in Osteoarthritis: A Study Using the National Joint Registry and Clinical Practice Research Datalink Data Sets.

OBJECTIVE: To estimate the costs of primary hip and knee replacement in individuals with osteoarthritis up to 2 years postsurgery, compare costs before and after the surgery, and identify predictors of hospital costs. METHODS: Patients age ≥18 years with primary planned hip or knee replacements and osteoarthritis in England between 2008 and 2016 were identified from the National Joint Registry and linked with Hospital Episode Statistics data containing inpatient episodes. Primary care data linked with hospital outpatient records were also used to identify patients age ≥18 years with primary hip or knee replacements between 2008 and 2016. All health care resource use was valued using 2016/2017 costs, and nonparametric censoring methods were used to estimate total 1-year and 2-year costs. RESULTS: We identified 854,866 individuals undergoing hip or knee replacement. The mean censor-adjusted 1-year hospitalization costs for hip and knee replacement were £7,827 (95% confidence interval [95% CI] 7,813, 7,842) and £7,805 (95% CI 7,790, 7,818), respectively. Complications and revisions were associated with up to a 3-fold increase in 1-year hospitalization costs. The censor-adjusted 2-year costs were £9,258 (95% CI 9,233, 9,280) and £9,452 (95% CI 9,430, 9,475) for hip and knee replacement, respectively. Adding primary and outpatient care, the mean total hip and knee replacement 2-year costs were £11,987 and £12,578, respectively. CONCLUSION: There are significant costs following joint replacement. Revisions and complications accounted for considerable costs and there is a significant incentive to identify best approaches to reduce these.

Day-case unicompartmental knee arthroplasty: a literature review and development of a novel hospital pathway.

INTRODUCTION: We have seen unparalleled changes in our healthcare systems globally as a result of the COVID-19 pandemic. As we strive to regenerate our full capacity elective services in order to contest the increasing demand for lower limb arthroplasty, this pandemic has allowed us a rare opportunity to revise and develop novel elective arthroplasty pathways intended to improve patient care and advance healthcare efficiency. We present an extensive evidence-based review of the approaches used to achieve day-case unicompartmental arthroplasty (UKA) as well as the development of a day-case UKA care pathway in a UK NHS institution based on the evidence provided in the literature. METHODS: An extensive search of the literature was performed for articles that reported on readmission or complication rates ≥30 days postoperatively following day-case UKA. FINDINGS: Fifteen manuscripts reporting the results of day-case UKA, defined as discharged on the same calendar day of surgery, were included in our review. Mean reported complication rates for day-case and inpatient UKA within the follow-up periods were 4.05% and 6.52%, respectively. Mean readmission rates were 2.71% and 4.36% for day-case and inpatient UKA, respectively. The mean rate of successful same-day discharge was 92.45%. CONCLUSION: We introduce our institutional Elective Day Surgery Arthroplasty Pathway (EDSAP) founded upon the evidence presented in the literature. Stringent patient selection complimented by a well-defined day-case arthroplasty pathway is fundamental for successful commencement of day-case UKA in the NHS.

Arthroscopic Partial Meniscectomy versus Physical Therapy for Degenerative Meniscal Tear: a Systematic Review.

BACKGROUND: Meniscal tears are commonly observed in patients with knee osteoarthritis (OA), however, clinical significance of such lesions detected by magnetic resonance imaging is in many cases unclear. This study aimed to determine the clinical effectiveness of arthroscopic partial meniscectomy (APM) compared with non-operative care in patients with knee OA. METHOD: We used existing systematic reviews with updates of latest studies. Three randomized controlled studies were selected, where two studies compared the effects of APM plus physical therapy (PT) with PT alone and one compared APM alone and PT alone. While 1 study exclusively included OA patients, 2 studies included 21.1 and 12% of patients with no radiographic OA. Patients with knee locking were unanimously excluded. RESULTS: Upon comparison of APM plus PT and PT alone, there was no significant difference observed in knee function, physical activity, or adverse events. Knee pain was observed to be significantly lower in the APM plus PT group at 6 months, but there was no difference between the two groups at 12 and 24 months. With respect to the comparison between APM alone and PT alone, PT was non-inferior based on the criteria for knee function during 24 months; however, knee pain was significantly reduced in the APM alone group. CONCLUSIONS: Our study showed that knee pain was significantly improved in the APM group compared to non-operative care group at 6 months and over 24 months. Our result was based on only 3 randomized controlled trials (RCTs) revealing a significant knowledge gap, hence demanding more high-quality RCTs in OA patients. TRIAL REGISTRATION: PROSPERO Identifier: CRD42020215965.

Indirect impact of Covid-19 on hospital care pathways in Italy.

Earlier in 2020, seven Italian regions, which cover 62% of the Italian population, set up the Mimico-19 network to monitor the side effects of the restrictive measures against Covid-19 on volumes and quality of care. To this aim, we retrospectively analysed hospital discharges data, computing twelve indicators of volume and performance in three clinical areas: cardiology, oncology, and orthopaedics. Weekly indicators for the period January-July 2020 were compared with the corresponding average for 2018-2019; comparisons were performed within 3 sub-periods: pre-lockdown, lockdown, and post-lockdown. The weekly trend of hospitalisations for ST-segment elevation myocardial infarction (STEMI) showed a 40% reduction, but the proportion of STEMI patients with a primary PTCA did not significantly change from previous years. Malignant neoplasms surgery volumes differed substantially by site, with a limited reduction for lung cancer (< 20%) and greater declines (30-40%) for breast and prostate cancers. The percentage of timely surgery for femoral neck in the elderly remained constantly higher than the previous 2 years whereas hip and knee replacements fell dramatically. Hospitalisations have generally decreased, but the capacity of a timely and effective response in time-dependent pathways of care was not jeopardized throughout the period. General trends did not show important differences across regions, regardless of the different burden of Covid-19. Preventive and primary care services should adopt a pro-active approach, moving towards the identification of at-risk conditions that were neglected during the pandemic and timely addressing patients to the secondary care system.

Evaluation of analgesic effect, joint function recovery and safety of meloxicam in knee osteoarthritis patients who receive total knee arthroplasty: A randomized, controlled, double-blind study.

ABSTRACT: Meloxicam is commonly administrated to control postoperative pain in orthopedic surgery, while its efficacy in total knee arthroplasty (TKA) is not clear. Therefore, this study aimed to explore the postoperative analgesic effect and tolerance of meloxicam in knee osteoarthritis (OA) patients undergoing TKA.Totally, 128 knee OA patients scheduled for TKA were enrolled in this randomized, controlled, double-blind study, then randomized into meloxicam group (N = 65) and control group (N = 63) as 1:1 ratio. Patients took meloxicam or placebo from 4 hours (h) to 72 h after TKA. Patients were followed up at 6 h, 12 h, day (D)1, D2, D3, D7, month (M)1, and M3.Pain visual analog scale score at rest was decreased in meloxicam group at 12 h, D1 and D3 compared to control group; pain visual analog scale score at flexion was reduced in meloxicam group at 6 h, 12 h, D1, D2, and D3 compared to control group. Additional and total consumption of patient-controlled analgesia were both attenuated in meloxicam group compared to control group. Furthermore, patient satisfaction score was higher on D1, D2, D3 in meloxicam group compared to control group. However, no difference of hospital for special surgery knee score score at M1 or M3 was found between the 2 groups. Moreover, the occurrence of adverse events was similar between the 2 groups.Meloxicam displays good effect on controlling postoperative pain and improving patient satisfaction, while does not affect long-term knee function recovery or safety profile in knee OA patients undergoing TKA.

Natural course of hemoglobin level after total knee arthroplasty and the benefit of tranexamic acid injection in the joint.

ABSTRACT: We retrospectively investigated the natural course of hemoglobin (Hb) level after total knee arthroplasty (TKA) and identified the benefit of tranexamic acid injection at the operation field for unilateral TKA patients who have not received blood transfusions.There were 115 cases conducted by a surgeon who performed TKA without injecting tranexamic acid and 62 cases by another surgeon with injection. During 2-weeks of hospitalization, Hb level was checked on the day of surgery and 1, 2, 3, 5, 7, 11 days after surgery.Regardless of whether whom the operator was and tranexamic acid was injected or not, the same natural course of Hb level after TKA was observed. The lowest value of Hb was shown at postoperative day 3, after which it tended to recover. In repeated measures analysis of variance test, mean difference from preoperative Hb level showed a statistically significant difference between tranexamic acid injected and noninjected groups (P = .01). In post hoc test, the differences from preoperative Hb levels were significantly lower at all measurements in surgeon with injection of tranexamic acid.When deciding whether to transfuse after TKA, it should be noted that the patient tends to show the lowest Hb level on postoperative day 3. Also, the authors emphasize that tranexamic acid injection in the joint at the operation field is an effective method to reduce the loss of Hb after TKA.

Association Between Same-Day Discharge Total Joint Arthroplasty and Risk of 90-Day Adverse Events in Patients with ASA Classification of ≥3.

BACKGROUND: Although safety in same-day discharge total joint arthroplasty (TJA) has been reported, findings are limited to healthier patients, specific surgeons, and/or specific institutions. Indications for same-day discharge TJA have expanded to include patients with multiple comorbidities; however, safety in this specific patient population remains unknown. Therefore, we sought to compare the risk of 90-day adverse events in higher-risk patients undergoing same-day discharge versus inpatient TJA. METHODS: The Kaiser Permanente Total Joint Replacement Registry was utilized to conduct a cohort study. All patients with an American Society of Anesthesiologists (ASA) classification of ≥3 who underwent primary elective TJA for osteoarthritis from 2017 through 2018 were identified. The risk of 90-day adverse events (i.e., emergency department visits, unplanned readmissions, complications, and mortality) was evaluated with use of propensity score-weighted Cox proportional hazard regression including noninferiority testing with a margin of 1.10. RESULTS: The cohort included a total of 5,250 patients who underwent total hip arthroplasty and 9,752 patients who underwent total knee arthroplasty, of whom 1,742 (33.2%) and 3,283 (33.7%) had same-day discharge, respectively. Same-day discharge hip arthroplasty was noninferior to an inpatient stay in terms of emergency department visits (hazard ratio [HR], 0.73; 1-sided HR 95% upper bound [UB], 0.84), readmissions (HR, 0.47; 95% UB, 0.61), and complications (HR, 0.63; 95% UB, 0.75); we did not have evidence of noninferiority for mortality (HR, 0.84; 95% UB, 1.97). Same-day discharge knee arthroplasty was noninferior to an inpatient stay in terms of emergency department visits (HR, 0.79; 95% UB, 0.87), readmission (HR, 0.80; 95% UB, 0.95), complications (HR, 0.72; 95% UB, 0.82), and mortality (HR, 0.53; 95% UB, 1.03). CONCLUSIONS: We found that same-day discharge TJA did not increase the risk of emergency department visits, unplanned readmissions, and complications compared with an inpatient stay for higher-risk patients, suggesting that it is possible to expand indications for same-day discharge TJA in the hospital setting while maintaining safety. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Warfarin use and risk of knee and hip replacements.

BACKGROUND: Identification of modifiable risk factors and treatments for osteoarthritis (OA) are needed. Warfarin, a vitamin K antagonist, causes fetal and animal model skeletal abnormalities. Vitamin K insufficiency has been associated with OA, but whether warfarin is also detrimental to OA is not known. METHODS: We conducted a nested case-control study using a UK general practitioner electronic medical records database. We identified cases of knee or hip replacement (KR or HR) from among adults with atrial fibrillation newly prescribed either warfarin or direct oral anticoagulants (DOACs). Cases were matched with four controls by age and sex. We assessed the relation of warfarin compared with DOAC use to risk of joint replacement using conditional logistic regression. We also evaluated different durations of warfarin use. RESULTS: We identified 857 subjects with KR or HR (cases), of whom 64.6% were warfarin users, and 3428 matched controls, of whom 56.1% were warfarin users (mean age 75, 47% female). Warfarin users had a 1.59 times higher risk of joint replacement than DOAC users (adjusted OR 1.59, 95% CI 1.31 to 1.92). Longer duration of warfarin use was associated with higher risk of joint replacement in comparison with <1 year of warfarin use. CONCLUSION: Warfarin, a vitamin K antagonist, was associated with greater risk of KR and HR (an indicator for end-stage knee OA) than DOAC use, supporting the importance of adequate vitamin K functioning in limiting OA progression.

Outcomes of Bulk Fresh Osteochondral Allografts for Cartilage Restoration in the Knee.

BACKGROUND: Symptomatic osteochondral defects of the knee in young patients can cause substantial disability and predispose to osteoarthritis. Fresh osteochondral allografts (FOCAs) are a treatment option for such defects. With our institution having one of the longest-running FOCA programs, we investigated the long-term outcomes of bulk FOCA in the knee, focusing on graft survivorship, function, complications, and reoperation. METHODS: A total of 244 patients underwent bulk FOCA in the knee from 1972 to 2018, with a mean age of 37.8 years (range, 10 to 75 years) and a mean follow-up of 9.0 years (range, 1.0 to 29.8 years). Cartilage defects were very large and uncontained, such that they were not amenable to plug transplantation. Survivorship according to Kaplan-Meier analysis was the primary outcome, and failure was defined as conversion to total knee arthroplasty, repeat allograft, graft removal, knee arthrodesis, or amputation. Functional outcome was evaluated with use of the modified Hospital for Special Surgery (mHSS) score, and radiographic evidence of osteoarthritis was classified with use of the Kellgren-Lawrence grading scale. RESULTS: Graft survivorship was 86.6% at 5 years, 73.3% at 10 years, 58.1% at 15 years, 43.7% at 20 years, 31.9% at 25 years, and 22.6% at 30 years. The most common complications were pain (14.8%), malalignment (13.9%), and stiffness (5.8%). A total of 93 grafts (38.1%) failed at a mean of 11.0 years (range, 0.5 to 34.0 years). The mean mHSS score improved significantly, from 68.7 (range, 19 to 91) preoperatively to 80.3 (range, 52 to 100) at the time of the latest follow-up (p < 0.001). Preoperative mHSS score had a negative correlation with Kellgren-Lawrence grade at the time of the latest follow-up. Multivariate analysis revealed that graft location (i.e., medial-sided or multiple grafts) and increased age were significantly negatively associated with survival. Ten-year survival was >80% in patients below 50 years old, but <40% in patients >60 years old. CONCLUSIONS: Bulk FOCA provided promising long-term graft survival and functional improvement in patients <50 years old. It can delay or prevent the need for total knee arthroplasty in young patients. Older patients and patients with a medial-sided graft, or multiple grafts within the same knee, had a less favorable prognosis. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

How Large a Study Is Needed to Detect TKA Revision Rate Reductions Attributable to Robotic or Navigated Technologies? A Simulation-based Power Analysis.

BACKGROUND: Robotic and navigated TKA procedures have been introduced to improve component placement precision in the hope of improving implant survivorship and other clinical outcomes. Although numerous comparative studies have shown enhanced precision and accuracy in placing components, most comparative studies have not shown that such interventions result in improved implant survival. Given what we know about effect sizes from large arthroplasty registries, large cohort studies, and large randomized controlled trials (RCTs), we wondered how large randomized trials would need to be to detect such small differences, and if the number is very high, what that would tell us about the value of these treatments for preventing revision surgery. QUESTIONS/PURPOSES: In this simulation study, we asked: Given that survivorship differences between technology-assisted TKA (TA-TKA, which we defined as either navigated or robot-assisted TKA) and conventional TKA are either small or absent based on large arthroplasty registries, large cohort studies, and large RCTs, how large would randomized trials need to be to detect small differences between TA-TKA and conventional TKA if they exist, and how long would the follow-up period need to be to have a reasonable chance to detect those differences? METHODS: We used estimated effect sizes drawn from previous clinical and registry studies, combined with estimates of the accuracy and precision of various navigation and robotic systems, to model and simulate the likely outcomes of potential comparative clinical study designs. To characterize the ranges of patients enrolled and general follow-up times associated with traditional RCT studies, we conducted a structured search of previously published studies evaluating the effect of robotics and navigation on revision rates compared with that of conventional TKA. The structured search of the University of British Columbia's library database (which automatically searches medical publication databases such as PubMed, Embase, Medline, and Web of Science) and subsequent searching through included studies' reference lists yielded 103 search results. Only clinical studies assessing implant survival differences between patient cohorts of TA-TKA and conventional TKA were included. Studies analyzing registry data, using cadaver specimens, assessing revision TKA, conference proceedings, and preprint services were excluded. Twenty studies met all our inclusion criteria, but only one study reported a statistically significant difference between the conventional and robotic or navigated groups. Next, we generated a large set of patients with simulated TKA (1.5 million), randomly assigning each simulated patient a set of patient-specific factors (age at the index surgery, gender, and BMI) drawn from data from registries and published information. We divided this set of simulated procedures into four groups, each associated with a coronal alignment precision reported for different types of surgical procedures, and randomly assigned each patient an overall coronal alignment consistent with their group's precision. TA procedures were modeled based on the alignment precision that an intervention could deliver, regardless of whether the technology used was navigation- or robot-assisted. To evaluate the power associated with using different cohort sizes, we ran a Monte Carlo simulation generating 3000 simulated populations that were drawn (with replacement) from the large set of simulated patients with TKA. We simulated the time to revision for aseptic loosening for each patient, computed the corresponding Kaplan-Meier survival curves, and applied a log-rank test to each study for statistical differences in revision rates at concurrent follow-up timepoints (1-25 years). From each simulation associated with a given cohort size, we determined the percentage of simulated studies that found a statistically significant difference at each follow-up interval. For each alternative precision, we then also calculated the expected reduction in revision rates (effect size) attributable to TA-TKA intervention and the number needed to treat (NNT) using TA-TKA to prevent one revision at 2, 5, 10, and 15 years after index surgery for the entire set of Kaplan-Meier survival analyses. RESULTS: The results from our simulation found survivorship differences favoring TA-TKA ranging from 1.4% to 2.0% at 15 years of follow-up. Comparative studies would need to enroll between 2500 and 4000 patients in each arm of the study, depending on the precision of the navigated or robotic procedure, to have an 80% chance of showing this reduction in revision rates at 15 years of follow-up. For the highest precision simulated intervention, the NNT using TA-TKA to prevent one revision was 1000 at 2 years, 334 at 5 years, 100 at 10 years, and 50 at 15 years post-index surgery. CONCLUSION: Based on these simulations, it appears that TA-TKA interventions could potentially result in a relative reduction in revision rates as large as 27% (from 7.5% down to about 5.5% at 15 years for the intervention with the most precise coronal alignment); however, since this 2% absolute reduction in revision rates is relatively small in comparison with the baseline success rate of TKA and would not be realized until 15 years after the index surgery, traditional RCT studies would require excessively large numbers of patients to be enrolled and excessively long follow-up times to demonstrate whether such a reduction actually exists. CLINICAL RELEVANCE: Given that the NNTs to avoid revisions at various time points are predicted to be high, it would require correspondingly low system costs to justify broad adoption of TA-TKA based on avoided revision costs alone, though we speculate that technology assistance could perhaps prove to be cost effective in the care of patients who are at an elevated risk of revision.

Assessment of Racial Disparities in the Risks of Septic and Aseptic Revision Total Knee Replacements.

Importance: Black patients are at higher risk of revision total knee replacement (TKR) than White patients, but whether racial disparities exist for both septic and aseptic revision TKR and the reason for any disparities are unknown. Objective: To assess the risk of septic and aseptic revision TKR in Black and White patients and to examine interactions among race and socioeconomic and hospital-related variables that are associated with revision TKR risk. Design, Setting, and Participants: This cohort study included residents of New York, California, and Florida who underwent TKR. Patient-level data were obtained from the New York Statewide Planning and Research Cooperative System, California's Office of Statewide Health Planning and Development Patient Discharge Database, and Florida's Healthcare Utilization Project State Inpatient Database from January 1, 2004, to December 31, 2014. Community characteristics were calculated from the US Census and linked to discharges by patient zip code. American Hospital Association Annual Survey data were linked to discharges using hospital identifiers. The analyses were performed from March 1 to October 30, 2020, with subsequent analyses in April 2021. Main Outcomes and Measures: Cox proportional hazards regression modeling was used to measure the association of race with septic and aseptic revision TKR. Results: A total of 722 492 patients underwent primary TKR, of whom 445 616 (61.68%) were female and 61 092 (8.46%) were Black. Black patients were at higher risk of septic (hazard ratio [HR], 1.11; 95% CI, 1.03-1.20) and aseptic (HR, 1.39; 95% CI, 1.33-1.46) revision TKR compared with White patients. Other risk factors for septic revision TKR were diabetes (HR, 1.24; 95% CI, 1.17-1.30), obesity (HR, 1.13; 95% CI, 1.17-1.30), kidney disease (HR, 1.42; 95% CI, 1.29-1.57), chronic obstructive pulmonary disease (HR, 1.22; 95% CI, 1.15-1.30), inflammatory arthritis (HR, 1.53; 95% CI, 1.39-1.69), surgical site complications during the index TKR (HR, 2.19; 95% CI, 1.87-2.56), Medicaid insurance (HR, 1.17; 95% CI, 1.04-1.31), and low annual TKR volume at the hospital where the index TKR was performed (HR, 1.54; 95% CI, 1.41-1.68). Risk factors for aseptic revision TKR were male sex (HR, 1.03; 95% CI, 1.00-1.06), workers' compensation insurance (HR, 1.61; 95% CI, 1.51-1.72), and low hospital TKR volume (HR, 1.14; 95% CI, 1.07-1.22). Patients with obesity had a lower risk of aseptic TKR revision (HR, 0.81; 95% CI, 0.77-0.84). In an analysis within each category of hospital TKR volume, the HR for aseptic revision among Black vs White patients was 1.20 (95% CI, 1.04-1.37) at very-low-volume hospitals (≤89 TKRs annually) compared with 1.68 (95% CI, 1.48-1.90) at very-high-volume hospitals (≥645 TKRs annually). Conclusions and Relevance: In this cohort study, Black patients were at significantly higher risk of aseptic revision TKR and, to a lesser extent, septic revision TKR compared with White patients. Racial disparities in aseptic revision risk were greatest at hospitals with very high TKR volumes.