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.

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.

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.

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.

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.

Patellar Resurfacing in Total Knee Arthroplasty: A Cost-Effectiveness Analysis.

BACKGROUND: This study estimates the cost-effectiveness of patellar resurfacing in total knee arthroplasty (TKA). METHODS: We conducted a cost-effectiveness analysis using a decision analytic model representing a hypothetical TKA cohort, with or without patellar resurfacing, using data from the 2014 Australian Registry. The model represents 3 possible postoperative health states: (1) well, (2) patellofemoral pain, or (3) serious adverse event (any event resulting in a revision). Our effectiveness outcome was the quality-adjusted life year, from published utility scores. We estimated cost-effectiveness from a Canadian public healthcare payer perspective. Costs and quality of life were valued in 2015 United States dollars and discounted annually at 5%. RESULTS: Our results suggest that TKA with resurfacing is cost-effective compared to nonresurfacing. Unresurfacing the patellae resulted in higher costs ($13,296.63 vs $12,917.01) and lower quality-adjusted life year (5.37 vs 6.01) at 14 years. Sensitivity analysis suggests that if rates of secondary resurfacing are <0.5%, there was no cost difference. CONCLUSION: Over 14 years postoperative, patellar resurfacing appears to be cost-effective, due to higher revision rates for unresurfaced TKA. Although our results suggest resurfacing improves quality of life, our model is limited by the availability and validity of long-term utility outcomes reported for TKA. Our cost-effectiveness analysis showed superiority of the resurfacing compared to retention of the patella.

Cost-Effectiveness of Total Hip Arthroplasty Versus 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 hip arthroplasty (THA) vs nonoperative management (NM) among 6 body mass index (BMI) cohorts. METHODS: We constructed a state-transition Markov model to compare the cost utility of THA and NM in the 6 BMI groups over a 15-year period. Model parameters for transition probability (risk of revision, re-revision, and death), utility, and costs (inflation adjusted to 2017 US dollars) were estimated from the literature. Direct medical costs of managing hip arthritis were accounted in the model. Indirect societal costs were not included. A 3% annual discount rate was used for costs and utilities. The primary outcome was the incremental cost-effectiveness ratio (ICER) of THA vs NM. One-way and Monte Carlo probabilistic sensitivity analyses of the model parameters were performed to determine the robustness of the model. RESULTS: Over the 15-year time period, the ICERs for THA vs NM were the following: normal weight ($6043/QALYs [quality-adjusted life years]), overweight ($5770/QALYs), obese ($5425/QALYs), severely obese ($7382/QALYs), morbidly obese ($8338/QALYs), and super obese ($16,651/QALYs). The 2 highest BMI groups had higher incremental QALYs and incremental costs. The probabilistic sensitivity analysis suggests that THA would be cost-effective in 100% of the normal, overweight, obese, severely obese, and morbidly obese simulations, and 99.95% of super obese simulations at an ICER threshold of $50,000/QALYs. CONCLUSION: Even at a willingness-to-pay threshold of $50,000/QALYs, which is considered low for the United States, our model showed that THA would be cost-effective for all obesity levels. BMI cut-offs for THA may lead to unnecessary loss of healthcare access.

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

BACKGROUND: We compared 90-day costs and outcomes for primary total knee arthroplasty patients among nonobese (body mass index [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+) cohorts. METHODS: We conducted a retrospective review of an institutional database of total knee arthroplasty patients from 2006 to 2013 with a minimum of 3-year follow-up. Sixty-five super-obese patients were identified, and five other cohorts were randomly selected in a 2:1 ratio (total, n = 715). Demographics, 90-day outcomes (costs, reoperations, and readmissions), and outcomes after 3 years (revisions and change scores for Short-Form Health Survey [SF-12], Knee Society Scores, and Western Ontario and McMaster Universities Arthritis Index) were aggregated. RESULTS: The 90-day costs were significantly greater in the morbidly obese ($11,568 ± $1,960) and super-obese ($14,021 ± $7,903) cohorts relative to the smaller BMI cohorts ($9,938 - $10,352). The increased cost from readmissions was the main driver of costs. The outcome change scores were similar across all the BMI cohorts for Knee Society Scores, SF-12 Mental Health Composite Score, and Western Ontario and McMaster Universities Arthritis Index, but not for the SF-12 Physical Health Composite Score. At the midterm follow-up, there was no statistical difference in repeat surgery or aseptic revision rates. Septic revisions were significantly greater in the super-obese cohort relative to the other cohorts (6.2% vs 0.8-3.1%). CONCLUSION: Health-care policy based purely on the economic costs may place morbidly obese and super-obese patients at risk of losing arthroplasty care, thereby denying them access to the comparable quality of life improvements.

In-Hospital Cost Analysis of Total Hip Arthroplasty: Does Surgical Approach Matter?

The purposes of this study were to determine the impact of surgical approach on costs of total hip arthroplasty (THA) from a hospital perspective and to provide an updated cost estimation of THA. A prospective, microcosting analysis was performed on 118 patients undergoing a THA through an anterior, lateral, or posterior approach. We determined that overall costs (intraoperative costs and hospital stay) were significantly less for the anterior ($7300.22; 95% confidence interval [CI], 7064.49-7535.95) vs lateral ($7853.10; 95% CI, 7577.29-8128.91; P = .031) and anterior vs posterior approach ($8287.46; 95% CI, 7906.42-8668.51; P < .001). A reduction in hospital length of stay when THA was performed through an anterior approach contributed significantly to an overall reduction in costs from a hospital perspective.