Predictors of Undergoing Revision Within 5 Years of Total Knee Arthroplasty: A Population-Based Study.

BACKGROUND: The objective of this study was to identify the rate and risk factors for revision total knee arthroplasty (TKA) within the first 5 years postoperative. Our secondary objective was to identify the rate of additional surgical procedures and death. METHODS: We conducted a retrospective cohort study among patients in Ontario, Canada who underwent an elective, primary TKA between April 1, 2007, and March 31, 2014, for osteoarthritis. We excluded patients under 40 years and who had undergone a TKA within the previous 15 years. Our final study cohort included 94,193 patients. We reported the proportion of the study cohort who experienced revision surgery within 2 and 5 years of the primary TKA; secondary surgery within 5 years. We conducted Cochran-Armitage tests for trends to assess changes in the proportion of patients who experienced each of the study outcomes, and multivariable logistic regressions to evaluate predictors of a revision TKA. RESULTS: There were 3,112 (3.3%) patients who had a revision within 5 years, and 1,866 (2.0%) within 2 years of their primary TKA. 3,316 (3.5%) had a secondary surgery (0.6% patellar resurfacing; 1.6% manipulation; 1.3% synovectomy; 0.5% washout; 0.9% debridement). Lower age, men, lower income, higher comorbidity score, depression, previous arthroscopy, lower surgeon volume, and general anesthesia were all significant positive predictors of revision. CONCLUSIONS: In our study cohort, 2.0% of patients had a revision TKA within 2 years, and 3.3% within 5 years of their primary TKA. Preoperative identification of risk factors may reduce the future prevalence of revision TKAs.

Logistic Regression and Machine Learning Models Cannot Discriminate Between Satisfied and Dissatisfied Total Knee Arthroplasty Patients.

BACKGROUND: Approximately 20% of total knee arthroplasty (TKA) patients are found to be dissatisfied or unsure of their satisfaction at 1-year post-surgery. This study attempted to predict 1-year post-surgery dissatisfied/unsure TKA patients with pre-surgery and surgical variables using logistic regression and machine learning methods. METHODS: A retrospective analysis of patients who underwent primary TKA for osteoarthritis between 2012 and 2016 at a single institution was completed. Patients were split into satisfied and dissatisfied/unsure groups. Potential predictor variables included the following: demographic information, patella re-surfaced, posterior collateral ligament sacrificed, and subscales from the Knee Society Knee Scoring System, the Knee Society Clinical Rating System, the Western Ontario and McMaster Universities Osteoarthritis Index, and the 12-Item Short Form Health Survey version 2. Logistic regression and 6 different machine learning methods were used to create prediction models. Model performance was evaluated using discrimination (AUC [area under the receiver operating characteristic curve]) and calibration (Brier score, Cox intercept, and Cox slope) metrics. RESULTS: There were 1432 eligible patients included in the analysis, 313 were considered to be dissatisfied/unsure. When evaluating discrimination, the logistic regression (AUC = 0.736) and extreme gradient boosted tree (AUC = 0.713) models performed best. When evaluating calibration, the logistic regression (Brier score = 0.141, Cox intercept = 0.241, and Cox slope = 1.31) and gradient boosted tree (Brier score = 0.149, Cox intercept = 0.054, and Cox slope = 1.158) models performed best. CONCLUSION: The models developed in this study do not perform well enough as discriminatory tools to be used in a clinical setting. Further work needs to be done to improve the performance of pre-surgery TKA dissatisfaction prediction models.

The cost of outpatient versus inpatient total hip arthroplasty: a randomized trial.

BACKGROUND: One route to mitigate the increasing costs of total hip arthroplasty (THA) is outpatient THA, discharging patients on the same day as their surgery. The purpose of this study was to compare the cost of outpatient THA to standard overnight stay in hospital. METHODS: This was a preliminary analysis of the first group of patients to complete follow-up in a larger randomized controlled trial among patients who underwent primary THA through a direct anterior approach between June 2015 and November 2017. The study was conducted at a single centre among patients of 1 fellowship-trained arthroplasty surgeon. We randomly allocated participants to be discharged either as outpatients or on postsurgery day 1 using a modified Zelen consent model. Adverse events were recorded. Participants completed cost questionnaires 2, 6 and 12 weeks after surgery, and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) before and 12 weeks after surgery. We performed cost analyses from health care payer and societal perspectives. RESULTS: A total of 115 participants completed this study, 49 allocated to the outpatient group and 56 to the inpatient group. The adverse event rate was similar for the 2 groups. The WOMAC total score and function subscale score were higher for the outpatient group than the inpatient group at 12 weeks (mean difference 2.1, 95% confidence interval [CI] 0.0 to 4.1, and 6.5, 95% CI 0.4 to 12.5, respectively). From both a health care payer and a societal perspective, inpatient THA was more costly than outpatient THA (mean difference $1006.86, 95% CI -$2158.92 to $145.21, and $1667.40, 95% CI -$3856.64 to $521.84, respectively). CONCLUSION: Our results suggest that outpatient THA may be a cost-saving procedure compared to inpatient THA from both health care payer and societal perspectives. Further study with larger samples is needed to provide more precision around our estimates. TRIAL REGISTRATION: ClinicalTrials.gov, no. NCT03026764.

Health care costs after total knee arthroplasty for satisfied and dissatisfied patients.

BACKGROUND: Evidence suggests that up to 21% of patients are dissatisfied after total knee arthroplasty (TKA), but the link between dissatisfaction and use of health care resources is unknown. The objective of this study was to compare costs after TKA between satisfied and dissatisfied patients. METHODS: This was a secondary analysis of a randomized clinical trial among patients who underwent primary TKA at our institution between 2015 and 2018. We estimated rates of satisfaction with pain relief and with return to function 1 year postoperatively. Patients prospectively reported use of health care resources 6 weeks, and 3, 6, 9 and 12 months after surgery. We compared costs between satisfied and dissatisfied patients from a public payer and a societal perspective. RESULTS: We included 156 patients in our analysis, of whom 42 (26.9%) were dissatisfied with pain, and 57 (36.5%) were dissatisfied with function. There was no significant difference in costs between patients dissatisfied with pain or function compared to satisfied patients from a health care payer perspective. From a societal perspective, patients dissatisfied with pain incurred a mean cost of $21 156.18, compared to $13 453.84 for satisfied patients (mean difference $7702.34, 95% confidence interval [CI] -89.43 to 15 494.11). Similarly, patients dissatisfied with function incurred a mean cost of $19 007.70, compared to $13 523.83 for those who were satisfied (mean difference $5483.87, 95% CI -526.34 to 11 494.10). CONCLUSION: Dissatisfied patients incurred greater costs than satisfied patients during the first year after TKA. The results justify further evaluation of factors contributing to patient satisfaction that may help to reduce the economic burden of TKA.

Hip arthroscopy utilization and reoperation rates in Ontario: a population-based analysis comparing different age cohorts.

BACKGROUND: Older age (> 40 yr) and osteoarthritis are negative prognostic variables for hip arthroscopy, but their impact has not been quantified from a population standpoint. The purpose of this study was to perform a population-based analysis of hip arthroscopy utilization and associated 2- and 5-year reoperation rates and complications in different age cohorts. METHODS: Administrative databases from Ontario, Canada, were retrospectively reviewed to identify patients aged 18-60 years who underwent hip arthroscopy between 2006 and 2016. Patients were stratified into 2 cohorts: 18-39 and 40-60 years of age. Patients were followed for 2 and 5 years to capture the occurrence of subsequent surgery (repeat arthroscopy or total hip arthroplasty) and postoperative complications. RESULTS: A total of 1906 patients underwent hip arthroscopy, 818 (42.9%) of whom were aged 40-60 years. In the entire cohort, revision surgery occurred in 6.5% and 15.1% of cases at 2 and 5 years, respectively. Revision surgery rates were significantly higher among patients aged 40-60 years at 2 (10.8% v. 3.2%, p < 0.001) and 5 years (22.7% v. 8.2%, p < 0.001) than among those aged 18-39 years. Revision rates were higher among patients aged 50-60 years than among those aged 40-49 years at 2 years (14.3% v. 9.1%, p = 0.027). Complication rates did not differ between cohorts. Regression analysis revealed higher 2- and 5-year odds of secondary surgery in patients aged 40-49 years (odds ratio [OR] 2.68, 95% confidence interval [CI] 1.70-4.22; OR 2.82, 95% CI 1.87-4.25; p < 0.001), patients aged 50-60 years (OR 4.39, 95% CI 2.67-7.22; OR 3.44, 95% CI 2.11-5.62; p < 0.001) and those with osteoarthritis (OR 2.41, 95% CI 1.39-4.20; p = 0.002; OR 1.76, 95% CI 1.00-3.09; p = 0.049). CONCLUSION: Revision surgery rates following hip arthroscopy are significantly higher among older patients and those with concomitant osteoarthritis. Although the data have limitations, they provide useful information to guide surgical decision-making.

The rate of unnecessary interventions for the management of knee osteoarthritis: a population-based cohort study.

BACKGROUND: Several commonly used procedures for knee osteoarthritis (OA) are not supported by evidence-based guidelines. The objective of this study was to identify the proportion of patients who underwent knee arthroscopy or magnetic resonance imaging (MRI) and the timing of these procedures before total knee arthroplasty (TKA). METHODS: We conducted a retrospective cohort study using administrative data sets from Ontario, Canada. We identified the proportion of patients who underwent knee arthroscopy in the previous 10 years or an MRI in the 3 years before their primary TKA. We also evaluated the rate of arthroscopies by diagnosis. We report the timing of each outcome in relation to the TKA, rates by geographical area, and differences in rates over time. RESULTS: We included 142 275 patients, of whom 36 379 (25.57%) underwent knee arthroscopy (median time 2.8 [interquartile range (IQR) 1.1-6.0] years); 22% of those were within 1 year of TKA and 52% were within 3 years. The rates of arthroscopies for a diagnosis of osteoarthritis (OA) steadily decreased, while those for meniscal-related diagnoses increased over the study period (p < 0.0001). There was significant variation by region. Of the cohort, 23.2% (n = 32 989) had an MRI before their TKA, with rates significantly increasing over time (p < 0.0001). CONCLUSION: A substantial proportion of patients with knee OA received diagnostic and therapeutic interventions before TKA that are contrary to clinical practice guidelines.

Total knee replacement after high tibial osteotomy: time-to-event analysis and predictors.

BACKGROUND: An important aim of high tibial osteotomy (HTO) is to prevent or delay the need for total knee replacement (TKR). We sought to estimate the frequency and timing of conversion from HTO to TKR and the factors associated with it. METHODS: We prospectively evaluated patients with osteoarthritis (OA) of the knee who underwent medial opening wedge HTO from 2002 to 2014 and analyzed the cumulative incidence of TKR in July 2019. The presence or absence of TKR on the HTO limb was identified from the orthopedic surgery reports and knee radiographs contained in the electronic medical records for each patient at London Health Sciences Centre. We used cumulative incidence curves to evaluate the primary outcome of time to TKR. We used multivariable Cox proportional hazards analysis to assess potential preoperative predictors including radiographic disease severity, malalignment, correction size, pain, sex, age, body mass index (BMI) and year of surgery. RESULTS: Among 556 patients who underwent 643 HTO procedures, the cumulative incidence of TKR was 5% (95% confidence interval [CI] 3%-7%) at 5 years and 21% (95% CI 17%-26%) at 10 years. With the Cox proportional hazards multivariable model, the following preoperative factors were significantly associated with an increased rate of conversion: radiographic OA severity (adjusted hazard ratio [HR] 1.96, 95% CI 1.12-3.45), pain (adjusted HR 0.85, 95% CI 0.75-0.96)], female sex (adjusted HR 1.67, 95% CI 1.08-2.58), age (adjusted HR 1.50 per 10 yr, 95% CI 1.17-1.93) and BMI (adjusted HR 1.31 per 5 kng/m2, 95% CI 1.12-1.53). INTERPRETATION: We found that 79% of knees did not undergo TKR within 10 years after undergoing medial opening wedge HTO. The strongest predictor of conversion to TKR is greater radiographic disease at the time of HTO.

Using Telerehabilitation to Deliver a Home Exercise Program to Youth With Arthrogryposis: Single Cohort Pilot Study.

BACKGROUND: Arthrogryposis multiplex congenita (AMC) is characterized by joint contractures and muscle weakness, which limit daily activities. Youths with AMC require frequent physical therapeutic follow-ups to limit the recurrence of contractures and maintain range of motion (ROM) and muscle strength; however, access to specialized care may be limited because of geographical distance. Telerehabilitation can offer a potential solution for delivering frequent follow-ups for youth with AMC, but research on the use of telerehabilitation in children with musculoskeletal disorders is scarce. OBJECTIVE: The study aims to evaluate the feasibility of delivering a home exercise program (HEP) by using telerehabilitation for youth with AMC. We also aim to explore the effectiveness of the HEP as a secondary aim. METHODS: Youths aged between 8 and 21 years with AMC were recruited at the Shriners Hospitals for Children-Canada. The participants completed baseline and post-HEP questionnaires (the Physical Activity Questionnaire for Adolescents, Pediatrics Outcomes Data Collection Instrument, and Adolescent and Pediatric Pain Tool), and clinicians assessed their active ROM using a virtual goniometer. Clinicians used the Goal Attainment Scale with the participants to identify individualized goals to develop a 12-week HEP and assess the achievement of these goals. Follow-ups were conducted every 3 weeks to adjust the HEP. Data on withdrawal rates and compliance to the HEP and follow-ups were collected to assess the feasibility of this approach. The interrater reliability of using a virtual goniometer was assessed using the intraclass correlation coefficient and associated 95% CI. Nonparametric tests were used to evaluate feasibility and explore the effectiveness of the HEP. RESULTS: Of the 11 youths who were recruited, 7 (median age: 16.9 years) completed the HEP. Of the 47 appointments scheduled, 5 had to be rescheduled in ≤24 hours. The participants performed their HEP 2.04 times per week (95% CI 1.25-4.08) and reported good satisfaction with the approach. A general intraclass correlation coefficient of 0.985 (95% CI 0.980-0.989) was found for the web-based ROM measurement. Individualized goals were related to pain management; endurance in writing, standing, or walking; sports; and daily activities. In total, 12 of the 15 goals set with the participants were achieved. Statistically significant improvements were observed in the pain and comfort domain of the Pediatrics Outcomes Data Collection Instrument (preintervention: median 71; 95% CI 34-100; postintervention: median 85; 95% CI 49-100; P=.08) and Physical Activity Questionnaire for Adolescents (preintervention: median 1.62; 95% CI 1.00-2.82; postintervention: median 2.32; 95% CI 1.00-3.45; P=.046). CONCLUSIONS: The remote delivery of an HEP for youth with AMC is feasible. Promising results were found for the effectiveness of the HEP in helping youths with AMC to achieve their goals. The next step will be to assess the effectiveness of this exercise intervention in a randomized controlled trial. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/18688.

Persistent post-operative opioid use following hip arthroscopy is common and is associated with pre-operative opioid use and age.

PURPOSE: Hip arthroscopy utilization continues to increase worldwide. Post-operative pain management is essential to allow appropriate rehabilitation. While multimodal analgesic protocols have been described, consensus agreement is lacking and opioid analgesia remains a mainstay of treatment. Unfortunately, the risk of persistent opioid use among opioid-naïve and non-naïve patients following hip arthroscopy remains unclear. Therefore, the purpose of this study was to identify rates of persistent post-operative opioid use, as well as to identify factors associated with persistent use. METHODS: A retrospective cohort study was conducted using linked administrative data from Ontario, Canada. Participants were adults who underwent hip arthroscopy between 2013 and 2018. Patients < 18 or > 60 years of age as well as those who had undergone prior hip arthroscopy were excluded. The primary exposure was whether patients had filled ≥ 2 opioid prescriptions within 1 year prior to their hip arthroscopy to define the opioid naïve and non-naïve populations. The primary outcome was persistent opioid use, defined as 2 + prescriptions filled between 9 and 15 months post-op. A regression analysis was performed to identify factors associated with persistent opioid usage. RESULTS: Of the 1909 patients, 1525 (79.9%) were opioid-naïve, while 384 (20.1%) had a prior history of opioid use within 1 year of surgery. 224 patients (11.7%) demonstrated persistent opioid use, with ≥ 2 prescriptions filled between 9 and 15 months post-op. Of those, 42 (18.8%) cases were among opioid-naïve patients, while the remaining 182 (81.2%) were among non-naïve patients. The risk of persistent post-operative use was significantly higher in those with prior opioid use (OR 31.95, 95% CI 22.15-46.09; p < 0.0001). Regression analysis confirmed that pre-operative opioid use (OR 23.79, 95% CI 17.06-33.17; p < 0.0001) and older age (OR 1.04, 95% CI 1.02-1.05, p < 0.0001) were associated with increased risk of persistent post-operative opioid use. CONCLUSION: Following hip arthroscopy, persistent opioid use is common. New persistent use was identified in 2.7% of opioid-naïve patients, compared with continued use in 47.4% of non-naïve patients. Pre-operative opioid use and older age were associated with the greater risk of persistent post-operative opioid use. LEVEL OF EVIDENCE: Level III.

Assessment of Informal Caregiver Assistance and Strain With Total Hip and Knee Arthroplasty.

BACKGROUND: The purpose of our study is to assess which patient-related and caregiver-related factors are predictive of caregiver strain and assistance when caring for total hip and knee arthroplasty (THA and TKA) patients within 2 weeks after surgery. METHODS: We conducted a prospective study of caregivers of participants enrolled in 2 randomized trials. Caregivers provided demographics and completed the Caregiver Strain Index and Caregiver Assistance Scale pre-surgery and post-surgery. We performed backwards stepwise regression with mixed-effects negative binomial models to investigate predictors of caregiver strain and assistance for THA and TKA caregivers. RESULTS: Three hundred six caregiver/patient pairs were included. Our models of caregiver strain found Caregiver Assistance Scale scores and patient age to be predictive for all caregivers. We also found caregiver gender and smoking status to be predictive for THA caregivers and caregiver age to be predictive for TKA caregivers. Our models of assistance provided by caregivers found time (post-surgery vs pre-surgery) was predictive for all caregivers. We also found patient body mass index, and patient and caregiver gender to be predictive for THA caregivers, and patient and caregiver employment status and caregiver education level to be predictive for TKA caregivers. CONCLUSION: Our study identifies patient-related and caregiver-related factors which are associated with caregiver strain and assistance when caring for arthroplasty patients. As this is the first study to assess assistance provided by caregivers, it is important for future research to validate our results and to further explore whether patient-reported outcomes may also be related to assistance and strain.

A Randomized Trial Investigating the Cost-Utility of Patient-Specific Instrumentation in Total Knee Arthroplasty in an Obese Population.

BACKGROUND: Patient-specific instrumentation (PSI) has been introduced in total knee arthroplasty (TKA) with the goal of increased accuracy of component positioning by custom fitting cutting guides to the patient's bony anatomy. A criticism of this technology is the associated cost. The purpose of this randomized controlled trial was to determine the cost-utility of PSI compared with standard of care (SOC) instrumentation for TKA in an obese population. METHODS: Patients with body mass index greater than 30 with osteoarthritis and undergoing primary TKA were randomized to SOC or PSI. Patients completed a health care resource use diary and the EuroQol-5D at three, six, nine, and 12 months and the Western Ontario and McMaster Universities Osteoarthritis Index at three and 12 months postsurgery. We performed cost-utility and cost-effectiveness analyses from public health care payer and societal perspectives. RESULTS: One hundred seventy-three patients were included in the analysis with 86 patients randomized to PSI and 87 to SOC. PSI was dominated (more costly and less effective) by SOC from a health care payer perspective. From a societal perspective, an incremental cost-utility ratio was calculated at $11,230.00 per quality-adjusted life year gained, which is cost-effective at a willingness to pay threshold of $50,000. Net benefit analyses found PSI was not significantly cost-effective at any willingness to pay value from either perspective. CONCLUSION: Our results suggest that widespread adoption of PSI may not be economically attractive or clinically indicated. Future considerations are to compare long-term clinical outcomes and radiographic alignment between the groups.

Wait times, resource use and health-related quality of life across the continuum of care for patients referred for total knee replacement surgery.

Background: The escalating socioeconomic burden of knee osteoarthritis (OA) underscores the need for innovative strategies to reduce wait times for total knee arthroplasty (TKA). The purpose of this study was to evaluate resource use, costs and health-related quality of life (HRQoL) across the continuum of care for patients with knee OA. Methods: This was a prospective study of 383 patients recruited from a high-volume teaching hospital at different stages of care (referral, consultation and presurgery). Outcomes included health care resource use; costs captured from the health care payer, private sector and societal perspectives; HRQoL measured using the Western Ontario and McMaster Universities Osteoarthritis Index, the 12-Item Short Form Health Survey, and EuroQoL 5-Dimension 5-Level tool; wait times; and the proportion of referrals deemed suitable candidates for surgery. Results: The most commonly used conservative treatments were pharmacotherapy, exercise and lifestyle modification. Forty percent of patients referred for TKA were deemed not to be suitable candidates for surgery. The greatest proportion of costs was borne by the patient or private insurer; a small proportion was borne by the public payer. Across all stages of care, more than 60% of the total costs was attributed to productivity losses. HRQoL remained relatively stable throughout the waiting period (mean wait time from referral to TKA 13.2 mo) but improved postoperatively. Conclusion: The suboptimal primary care management of knee OA calls for the development of innovative models of care. This study may provide valuable guidance on the design and implementation of a new online educational platform to improve referral efficiency and expedite wait times for TKA.

Contexte: Le fardeau socioéconomique croissant de l'arthrose du genou rappelle que nous avons besoin de stratégies novatrices afin de réduire les temps d'attente pour l'arthroplastie totale du genou (ATG). Le but de cette étude est d'évaluer l'utilisation des ressources, les coûts et la qualité de vie liée à la santé (QVLS) dans tout le continuum des soins pour les patients souffrant d'arthrose du genou. Méthodes: Cette étude prospective a porté sur 383 patients recrutés dans un établissement d'enseignement fort achalandé, qui en étaient à différentes étapes du continuum de soins (demande de consultation, consultation et préchirurgie). Les paramètres incluaient l'utilisation des ressources en santé, les coûts du point de vue sociétal et des régimes d'assurance maladie publics et privés, la QVLS mesurée au moyen de l'indice WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index), du questionnaire Short Form Health Survey en 12 points et de l'outil EuroQoL appliqué à 5 dimensions et à 5 niveaux, les temps d'attente, et la proportion de demandes de consultation concernant des patients considérés comme de bons candidats à la chirurgie. Résultats: Les traitements conservateurs les plus utilisés étaient la pharmacothérapie, l'exercice et les modifications à l'hygiène de vie. Quarante pour cent des patients adressés en consultation pour ATG ont été considérés comme de bons candidats à la chirurgie. La plus grande part des coûts a été assumée par le patient ou un assureur privé; une faible part des coûts a été assumée par le régime public. À toutes les étapes du continuum, plus de 60 % des coûts totaux ont été attribués à des pertes de productivité. La QVLS est demeurée relativement stable tout au long de la période d'attente (temps d'attente moyen entre la consultation et l'ATG, 13,2 mois) mais s'est améliorée après la chirurgie. Conclusion: La prise en charge sous-optimale de l'arthrose du genou en soins primaires rappelle qu'il est nécessaire d'établir des modèles de soins novateurs. Cette étude pourrait faciliter la mise au point et l'application d'une nouvelle plateforme éducative en ligne pour améliorer l'efficience des demandes de consultation et abréger les temps d'attente pour l'ATG.

A protocol for a randomized controlled trial investigating the safety and cost-effectiveness of outpatient total hip arthroplasty.

BACKGROUND: A significant proportion of the overall cost of total hip arthroplasty (THA) results from the inpatient hospital stay following the procedure. Considering the substantial and increasing number of these procedures performed annually, shifting to an outpatient model of care where the patient is discharged home the same day as their surgery represents a potential for significant cost savings. The potential significant impact of an outpatient care model on constrained healthcare budgets and lack of high-quality evidence regarding its effectiveness warrants a rigorous comparative trial. The purpose of this prospective, randomized controlled trial is to evaluate outpatient care pathways for THA. Specifically, our objectives are to compare the rate of serious adverse events and estimate the cost-effectiveness of outpatient compared to standard inpatient THA. METHODS: We will include patients undergoing primary THA whom have an American Society of Anaesthetists status equal to or less than three, live within a 60-min driving distance of the institution and have an adult to accompany them home postoperatively and stay with them overnight. Consenting patients will be randomized to be discharged on the same day as surgery, as outpatients, or as inpatients according to standard of care (minimum of one night in hospital) using a modified Zelen consent model. The primary outcome measure is the incidence of serious adverse events at 30 days postoperative. Participants and their caregivers will complete secondary outcomes measures at each follow-up visit including patient-reported outcome measures and self-reported cost questionnaires. DISCUSSION: This protocol is the first randomized trial to use blinding to evaluate outpatient THA compared to standard overnight stay and first to prospectively perform a full economic evaluation. It is also the first adequately powered trial to prospectively assess the safety of outpatient THA. Successful completion of this study could have the potential to provide clinical evidence for the role of outpatient THA in current practice. TRIAL REGISTRATION: This study was retrospectively registered on ClinicalTrials.gov ( NCT03026764 ) on March 9th, 2016.

Trends in knee arthroscopy utilization: a gap in knowledge translation.

PURPOSE: To evaluate the longitudinal trends in knee arthroscopy utilization in relation to published negative randomized controlled trials, focusing on annual rates, patient demographics and associated 30-day post-operative complications. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried using Current Procedural Terminology billing codes to identify arthroscopy cases between 2006 and 2016. 30-day post-operative complications were identified, and potential risk factors analysed using univariate and multivariate analyses. RESULTS: 68,346 patients underwent knee arthroscopy, of which 47,446 (69.5%) represented partial meniscectomies. The annual procedural rate, as a proportion of all reported cases, increased significantly from 2006 (0.3%) to 2016 (1.6%; p < 0.001), along with a significant increase in average patient age (44.3 ± 15.5 to 48.4 ± 14.5; p < 0.001). Specifically focusing on the meniscectomy cohort, average patient age significantly increased from 47.9 ± 15.1 to 50.7 ± 13.5 (p = 0.001). The overall incidence of complications was 2.0% (n = 1333), with major complications in 0.9% (n = 639) and minor complications in 1.0% (n = 701). Common complications included a return to the operating room (0.5%), deep vein thrombosis/thrombophlebitis (0.4%), and superficial infection (0.2%). Operating time > 90 min, diabetes, steroid use, ASA class 2+, and dialysis-dependency were the predictors of overall complication rates. CONCLUSION: Despite the publication of negative trials and new clinical practice guidelines, knee arthroscopy utilization and average patient age continue to increase. Given the high utilization, even low adverse event rates equate to substantial numbers of patients with minor and major complications. The NSQIP data show a gap in knowledge translation to clinical practice and highlight the need for improved clinical guidelines. LEVEL OF EVIDENCE: Cohort study; Level III.

The economic impact of periprosthetic infection in total hip arthroplasty

Background: Periprosthetic joint infection (PJI) is the third leading cause of total hip arthroplasty (THA) failure. Although controversial, 2-stage revision remains the gold standard treatment for PJI in most situations. To date, there have been few studies describing the economic impact of PJI in today's health care environment. The purpose of the current study was to obtain an accurate estimate of the institutional cost associated with the management of PJI in THA and to assess the economic burden of PJI compared with primary uncomplicated THA. Methods: We conducted a review of primary THA cases and 2-stage revision THA for PJI at our institution. Patients were matched for age and body mass index. All costs associated with each procedure were recorded. Descriptive statistics were used to summarize the collected data. Mean costs, length of stay, clinic visits and readmission rates associated with the 2 cohorts were compared. Results: Fifty consecutive cases of revision THA were matched with 50 cases of uncomplicated primary THA between 2006 and 2014. Compared with the primary THA cohort, PJI was associated with a significant increase in mean length of hospital stay (26.5 v. 2.0 d, p < 0.001), mean number of clinic visits (9.2 v. 3.8, p < 0.001), number of readmissions (12 v. 1, p < 0.001) and average overall cost (Can$38 107 v. Can$6764, t = 8.3, p < 0.001). Conclusion: Treatment of PJI is a tremendous economic burden. Our data suggest a 5-fold increase in hospital expenditure in the management of PJI compared with primary uncomplicated THA.

Contexte: L'infection articulaire périprothétique (IAP) arrive au troisième rang des principales causes d'échec de l'arthroplastie (ou prothèse) totale de la hanche (PTH). Même si elle est controversée, la révision en 2 étapes demeure le traitement standard pour l'IAP dans la plupart des cas. À ce jour, peu d'études ont décrit l'impact économique de l'IAP dans l'environnement actuel des soins de santé. Le but de la présente étude était d'obtenir une estimation précise des coûts institutionnels associés à la prise en charge de l'IAP dans la PTH et d'évaluer le fardeau économique de l'IAP comparativement à une PTH primaire non compliquée. Méthodes: Nous avons passé en revue les cas de PTH primaire et de révision de PTH en 2 étapes pour cause d'IAP dans notre établissement. Les patients ont été assortis selon l'âge et l'indice de masse corporelle. Tous les coûts associés à chaque intervention ont été consignés. Des statistiques descriptives ont servi à résumer les données recueillies. Nous avons comparé les coûts moyens, la durée des séjours, les visites à la clinique et les taux de réadmission associés aux 2 cohortes. Résultats: Cinquante cas consécutifs de révision de PTH ont été assortis à 50 cas de PTH primaire non compliquée entre 2006 et 2014. Comparativement à la cohorte de PTH primaire, les cas d'IAP ont été associés à une augmentation significative de la durée moyenne du séjour hospitalier (26,5 j c. 2,0 j, p < 0,001), du nombre moyen de visites à la clinique (9,2 c. 3,8, p < 0,001), du nombre des réadmissions (12 c. 1, p < 0,001) et du coût global moyen (38 107 $ CA c. 6764 $ CA, t = 8,3, p < 0,001). Conclusion: Le traitement de l'IAP représente un énorme fardeau économique. Selon nos données, les dépenses hospitalières associées à sa prise en charge sont 5 fois plus grandes que pour la PTH primaire non compliquée.

Ninety-Day Costs, Reoperations, and Readmissions for Primary Total Hip Arthroplasty Patients of Varying Body Mass Index Levels.

BACKGROUND: The purpose of this study is to compare 90-day costs and outcomes for primary total hip arthroplasty patients between a nonobese (body mass index, 18.5-24.9) vs overweight (25-29.9), obese (30-34.9), severely obese (35-39.9), morbidly obese (40-44.9), and super obese (45+) cohorts. METHODS: We conducted a retrospective review of an institutional database of primary total hip arthroplasty patients from 2006 to 2013. Thirty-three super-obese patients were identified, and the other 5 cohorts were randomly selected in a 2:1 ratio (n = 363). Demographics, 90-day outcomes (costs, reoperations, and readmissions), and outcomes after 3 years (revisions and change scores for Short-Form Health Survey, Harris Hip Score, and Western Ontario and McMaster Universities Arthritis Index) were collected. Costs were determined using unit costs from our institutional administrative data for all in-hospital resource utilization. Comparisons between the nonobese and other groups were made with Kruskal-Wallis tests for non-normal data and chi-square and Fisher exact test for categorical data. RESULTS: The 90-day costs in the morbidly obese ($13,134 ± $7250 mean ± standard deviation, P < .01) and super-obese ($15,604 ± 6783, P < .01) cohorts were significantly greater than the nonobese cohorts ($10,315 ± 1848). Only the super-obese cohort had greater 90-day reoperation and readmission rates than the nonobese cohort (18.2% vs 0%, P < .01 and 21.2% vs 4.5%, P = .02, respectively). Reoperations and septic revisions after 3 years were greater in the super-obese cohort compared to the nonobese cohort 21.2% versus 3.0% (P = .01) and 18.2% versus 1.5% (P = .01), respectively. Improvements in Short-Form Health Survey, Harris Hip Score, and Western Ontario and McMaster Universities Arthritis Index were comparable in all cohorts. CONCLUSION: Super-obese patients have greater risks and costs compared to nonobese patients, but also have comparable quality of life improvements.

Significant cost savings and similar patient outcomes associated with early discharge following total knee arthroplasty.

BACKGROUND: A substantial portion of the cost of total knee arthroplasty (TKA) results from the postoperative inpatient length of stay (LOS). Considering the annual increase in TKAs, reducing LOS represents a potential for cost savings. We sought to compare in-hospital costs and patient-reported outcomes for an early discharge protocol compared with the standard LOS following TKA. METHODS: We conducted a retrospective matched cohort study, matching patients on age, sex, body mass index and preoperative Western Ontario & McMaster Universities Osteoarthritis Index (WOMAC) score. We compared costs associated with time in the operating room, intraoperative pain control and inpatient stay as well as 1-year postoperative patient-reported outcomes between early discharge and standard LOS groups. RESULTS: We included 50 patients in our study (25 per group). The average LOS in the early discharge group was 26.5 hours, compared with 48.9 hours in the standard care group. The early discharge group had higher intraoperative costs associated with pain control (mean difference 26.98, 95% confidence interval 14.41-37.90, p < 0.01); however, this difference was offset by substantial savings associated with the reduced LOS. The mean total cost for the early discharge group was $649.62 ± $281.71 versus $1279.71 ± $515.98 for the standard care group. There were no significant differences in SF12 or WOMAC scores between groups at 1 year postoperative. CONCLUSION: In-hospital costs were significantly lower with a postoperative day 1 discharge protocol than with standard LOS following TKA, with no difference in patient-reported outcomes.

CONTEXTE: Une portion substantielle du coût de l'arthroplastie pour prothèse totale du genou (PTG) est liée à la durée du séjour postopératoire. Compte tenu de l'augmentation annuelle des cas de PTG, abréger les séjours représente une source potentielle d'économies. Nous avons comparé les coûts hospitaliers et les résultats signalés par les patients avec un protocole de congé rapide et avec le séjour de durée standard après la PTG. MÉTHODES: Nous avons procédé à une étude de cohorte rétrospective appariée, où les patients étaient assortis selon le l'âge, le sexe, l'indice de masse corporelle et le score WOMAC (Western Ontario & McMaster Universities Osteoarthritis) préopératoire. Nous avons comparé les coûts associés au temps passé au bloc opératoire, au contrôle de la douleur peropératoire et au séjour hospitalier, de même que les résultats signalés par les patients 1 an après l'intervention entre les 2 groupes (congé rapide c. durée de séjour standard). RÉSULTATS: Nous avons inclus 50 patients dans notre étude (25 par groupe). Le séjour moyen du groupe soumis au congé rapide a été de 26,5 heures, contre 48,9 heures pour le séjour standard. Le groupe soumis au congé rapide a présenté des coûts peropératoires plus élevés associés au contrôle de la douleur (différence moyenne 26,98, intervalle de confiance de 95 % 14,41-37,90, p < 0,01); par contre, cette différence a été compensée par d'importantes économies associées à des séjours plus courts. Le coût total moyen pour le groupe soumis au congé rapide a été de 649,62 $ ± 281,71 $ contre 1279,71 $ ± 515,98 $ pour le séjour standard. On n'a noté aucune différence significative pour ce qui est des scores SF12 ou WOMAC entre les groupes 1 an après l'intervention. CONCLUSION: Les coûts perhospitaliers ont été significativement moindres avec le protocole de congé postopératoire rapide (après 1 jour), comparativement au séjour standard après la PTG, sans différence en ce qui concerne les résultats signalés par les patients.

The importance of costing perspective: an example evaluating the cost-effectiveness of a locking versus nonlocking plate in medial opening wedge high tibial osteotomy

Summary: High tibial osteotomy (HTO) fixation can be achieved using various plate designs. Compared with nonlocking plates, the stability of locking plates allows patients to return to weight-bearing and work sooner and may also decrease postoperative complications, introducing the potential for overall cost savings. However, material costs for locking plates are higher, and the plate bulkiness may lead to additional surgery to remove the plate. We conducted a retrospective study to evaluate the cost-effectiveness of a locking versus a nonlocking plate in HTO from both the health care payer and societal perspectives up to 12 months postoperative. We observed that from a health care payer perspective, the locking plate was not cost-effective. However, the locking plate was cost-effective from the societal perspective (addition of indirect costs, such as time off work). These findings highlight the importance of considering costing perspective in economic evaluations for chronic conditions, particularly in publicly funded health care systems.

Use of the Corail stem for revision total hip arthroplasty: evaluation of clinical outcomes and cost

Background: With the growing number of total hip arthroplasty (THA) procedures performed, revision surgery is also proportionately increasing, resulting in greater health care expenditures. The purpose of this study was to assess clinical outcomes and cost when using a collared, fully hydroxyapatite-coated primary femoral stem for revision THA compared to commonly used revision femoral stems. Methods: We retrospectively identified patients who underwent revision THA with a primary stem between 2011 and 2016 and matched them on demographic variables and reason for revision to a similar cohort who underwent revision THA. We extracted operative data and information on in-hospital resource use from the patients' charts to calculate average cost per procedure. Patient-reported outcomes were recorded preoperatively and 1 year postoperatively. Results: We included 20 patients in our analysis, of whom 10 received a primary stem and 10, a typical revision stem. There were no significant between-group differences in mean Western Ontario and McMaster Universities Osteoarthritis Index score, Harris Hip Score, 12-Item Short Form Health Survey (SF-12) Mental Composite Scale score or Physical Composite Scale score at 1 year. Operative time was significantly shorter and total cost was significantly lower (mean difference ­3707.64, 95% confidence interval ­5532.85 to ­1882.43) with a primary stem than with other revision femoral stems. Conclusion: We found similar clinical outcomes and significant institutional cost savings with a primary femoral stem in revision THA. This suggests a role for a primary femoral stem such as a collared, fully hydroxyapatite-coated stem for revision THA.

Contexte: Avec le nombre croissant d'interventions pour prothèse de hanche (PTH) effectuées, la chirurgie de révision est aussi proportionnellement en hausse, ce qui entraîne des coûts supérieurs pour le système de santé. Le but de cette étude était d'évaluer les résultats cliniques et le coût associés à l'emploi d'une prothèse fémorale primaire à collerette entièrement recouverte d'hydroxyapatite pour la révision de PTH, comparativement à d'autres prothèses d'usage courant utilisées pour les révisions. Méthodes: Nous avons identifié rétrospectivement les patients ayant subi une révision de PTH avec une prothèse primaire entre 2011 et 2016 et nous les avons assortis selon les caractéristiques démographiques et le motif de la révision à une cohorte similaire soumise à une révision de PTH. Nous avons extrait les données sur l'opération et sur l'utilisation des ressources hospitalières à partir des dossiers des patients pour calculer le coût par intervention. Les résultats déclarés par les patients ont été notés avant l'intervention et 1 an après. Résultats: Nous avons inclus 20 patients dans notre analyse, dont 10 ont reçu une prothèse primaire et 10, une révision de prothèse typique. On n'a noté aucune différence significative entre les groupes pour ce qui est du score WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) moyen pour l'arthrose, du score de Harris pour la hanche, ou des sous-échelles santé mentale ou santé physique à 1 an du questionnaire SF-12 (12-Item Short Form Health Survey). L'intervention a duré significativement moins longtemps et le coût a été significativement moindre (différence moyenne ­3707,64, intervalle de confiance de 95 % ­5532,85 à ­1882,43) avec une prothèse primaire qu'avec les autres prothèses de révision. Conclusion: Nous avons observé des résultats cliniques similaires et des économies significatives pour l'établissement avec la prothèse primaire utilisée pour la révision de PTH. Cela donne à penser que la prothèse fémorale primaire, par exemple, à collerette et entièrement recouverte d'hydroxyapatite, aurait un rôle à jouer pour la révision de PTH.

Cost-Effectiveness of Total Knee Arthroplasty vs Nonoperative Management in Normal, Overweight, Obese, Severely Obese, Morbidly Obese, and Super-Obese Patients: A Markov Model.

BACKGROUND: We estimated the cost-effectiveness of performing total knee arthroplasty (TKA) vs nonoperative management (NM) among 6 body mass index (BMI) cohorts. METHODS: A Markov model was used to compare the cost-utility of TKA and NM in 6 BMI groups (nonobese [BMI 18.5-24.9], overweight [25-29.9], obese [30-34.9], severely obese [35-39.9], morbidly obese [40-49.9], and super-obese [50+] patients) over a 15-year period. Model parameters for transition probability (ie, revision, re-revision, death), utility, and costs were estimated from the literature. Direct medical costs but not indirect societal costs were included in the model. Costs and utilities were discounted 3% annually. The primary outcome was the incremental cost-effectiveness ratio (ICER) of TKA vs NM. One-way and probabilistic sensitivity analyses of the model parameters were performed to determine the robustness of the model. RESULTS: Over the 15-year period, the ICERs for the TKA vs NM for the different BMI categories were nonobese ($3317/quality-adjusted life years [QALYs]), overweight ($2837/QALY), obese ($2947/QALY), severely obese ($3536/QALY), morbidly obese ($5531/QALY), and super-obese ($11,878/QALY). The higher BMI groups tended to have higher incremental QALYs and also higher incremental costs. The probabilistic sensitivity analysis with an ICER threshold of $30,000/QALY showed that TKA would be cost-effective in 100% of simulations of patients with a BMI<50 and 99.16% of super-obese simulations. CONCLUSION: While performing TKA on super-obese patients is more expensive, the substantial improvements in patient outcomes make it cost-effective. Therefore, withholding TKA care based on a BMI would lead to an unjustified loss of health-care access.