Direct Hospital Costs per Case of Periprosthetic Hip and Knee Joint Infections in Europe - A Systematic Review.

BACKGROUND: The rise of periprosthetic joint infections (PJIs) due to aging populations is steadily increasing the number of arthroplasties and treatment costs. This study analyzed the direct health care costs of PJI for total hip arthroplasty and total knee arthroplasty (TKA) in Europe. METHODS: The databases PubMed, Scopus, Embase, Cochrane, and Google Scholar were systematically screened for direct costs of PJI in Europe. Publications that defined the joint site and the procedure performed were further analyzed. Mean direct health care costs were calculated for debridement, antibiotics, and implant retention (DAIR), one-stage, and 2-stage revisions for hip and knee PJI, respectively. Costs were adjusted for inflation rates and reported in US-Dollar (USD). RESULTS: Of 1,374 eligible publications, 12 manuscripts were included in the final analysis after an abstract and full-text review. Mean direct costs of $32,933 were identified for all types of revision procedures for knee PJI. The mean direct treatment cost including DAIR for TKA after PJI was $19,476. For 2-stage revisions of TKA, the mean total cost was $37,980. For all types of hip PJI procedures, mean direct hospital costs were $28,904. For hip DAIR, one-stage and 2-stage treatment average costs of $7,120, $44,594, and $42,166 were identified, respectively. CONCLUSIONS: Periprosthetic joint infections are associated with substantial direct health care costs. As detailed reports on the cost of PJI are scarce and of limited quality, more detailed financial data on the cost of PJI treatment are urgently required.

Choice of Prosthetic Implant Combinations in Total Hip Replacement: Cost-Effectiveness Analysis Using UK and Swedish Hip Joint Registries Data.

BACKGROUND: Prosthetic implants used in total hip replacements (THR) have a range of bearing surface combinations (metal-on-polyethylene, ceramic-on-polyethylene, ceramic-on-ceramic, and metal-on-metal), head sizes (small [<36 mm in diameter] and large [≥36 mm in diameter]), and fixation techniques (cemented, uncemented, hybrid, and reverse hybrid). These can influence prosthesis survival, patients' quality of life, and healthcare costs. OBJECTIVES: To compare the lifetime cost-effectiveness of implants for patients of different age and sex profiles. METHODS: We developed a Markov model to compare the cost-effectiveness of various implants against small-head cemented metal-on-polyethylene implants. The probability that patients required 1 or more revision surgeries was estimated from analyses of more than 1 million patients in the UK and Swedish hip joint registries, for men and women younger than 55, 55 to 64, 65 to 74, 75 to 84, and 85 years and older. Implant and healthcare costs were estimated from local procurement prices, national tariffs, and the literature. Quality-adjusted life-years were calculated using published utility estimates for patients undergoing THR in the United Kingdom. RESULTS: Small-head cemented metal-on-polyethylene implants were the most cost-effective for men and women older than 65 years. These findings were robust to sensitivity analyses. Small-head cemented ceramic-on-polyethylene implants were most cost-effective in men and women younger than 65 years, but these results were more uncertain. CONCLUSIONS: The older the patient group, the more likely that the cheapest implants, small-head cemented metal-on-polyethylene implants, were cost-effective. We found no evidence that uncemented, hybrid, or reverse hybrid implants were the most cost-effective option for any patient group. Our findings can influence clinical practice and procurement decisions for healthcare payers worldwide.

Hip hemiarthroplasty for fractured neck of femur; a freedom of information study to assess national variation in implant selection and procurement.

INTRODUCTION: During 2016, according to the National Hip Fracture Database (NHFD), over 65,000 patients suffered a hip fracture of which approximately half underwent hemiarthroplasty. Clear guidelines exist on the usage of proven cemented implants. The Getting It Right First Time (GIRFT) Report highlighted the financial implications of 'unwarranted variation' and stressed the importance of rationalising and standardising service provision, in particular implant usage. The primary aims of this study were to investigate the variation in hip hemiarthroplasty implant usage and associated costs. We hypothesised there to be large variation in implants used and procurement costs. METHODS: Freedom of Information Requests (FOI) were sent to all 177 hospitals listed in the 2017 NHFD Report as treating hip fracture patients. All hospitals were asked for their most commonly used hemiarthroplasty implant and the cost of this, per patient. RESULTS: One hundred sixty six (94%) responses were received. Eighty four (51%) provided implant name and cost, 78 (47%) provided implant name but refused costs and 4 (3%) refused to provide any details. Nineteen different prostheses were used nationally with 20 hospitals using a non-ODEP (Orthopaedic Data Evaluation Panel) 10A implant. Average total cost was £725.00 (range £71-£1378). Significant cost variation was demonstrated for the same implants; one implant was £978.19 at it's most costly and £285.59 at it's cheapest. DISCUSSION: The aims of this study have been met. We have demonstrated huge variation in the implants used for hip hemiarthroplasty and their costs. Notwithstanding the nuances of departmental procurement processes, the financial implications for this variation are significant. CONCLUSIONS: This article demonstrates a requirement for rationalisation of implant usage and procurement in order to potentially improve patient outcomes and provide opportunities for significant cost saving in an already overstretched health service.

Are Ceramic Bearings Becoming Cost-Effective for All Patients Within a 90-Day Bundled Payment Period?

BACKGROUND: We analyzed whether the total hospital cost in a 90-day bundled payment period for ceramic-on-polyethylene (C-PE) and ceramic-on-ceramic (COC) total hip arthroplasty (THA) bearings was changing over time, and whether the cost differential between ceramic bearings and metal-on-polyethylene (M-PE) bearings was approaching the previously published tipping point for cost-effectiveness of US$325. METHODS: A total of 245,077 elderly Medicare patients (65+) who underwent primary THA between 2010 and 2015 were identified from the United States Medicare 100% national administrative hospital claims database. The total inpatient cost, calculated up to 90 days after index discharge, was computed using cost-to-charge ratios, and hospital payment was analyzed. The differential total inpatient cost of C-PE and COC bearings, compared to metal-on-polyethylene (M-PE), was evaluated using parametric and nonparametric models. RESULTS: After adjustment for patient and clinical factors, and the year of surgery, the mean hospital cost up to 90 days for primary THA with C-PE or COC was within ±1% of the cost for primary THA with M-PE bearings (P < .001). From the nonparametric analysis, the median total hospital cost was US$296-US$353 more for C-PE and COC than M-PE. Cost differentials were found to decrease significantly over time (P < .001). CONCLUSION: Patient and clinical factors had a far greater impact on the total cost of inpatient THA surgery than bearing selection, even when including readmission costs up to 90 days after discharge. Our findings indicate that the cost-effectiveness thresholds for ceramic bearings relative to M-PE are changing over time and increasingly achievable for the Medicare population.

Cost Analysis of Dual-Mobility Versus Large Femoral Head Constructs in Revision Total Hip Arthroplasty.

BACKGROUND: The purpose of this study is to report healthcare payer costs of dual-mobility (DM) and large femoral head (LFH) constructs in revision total hip arthroplasties (THAs). METHODS: A Markov model was constructed to analyze costs of re-interventions incurred by Medicare and private payers over a 3-year time horizon in patients who underwent unilateral revision THA with DM (n = 126) or LFH (n = 176) implants. Model states and probabilities were derived from prospectively collected registry data. Medicare costs were estimated as the weighted-average national Medicare payment for revision THA. Private payer costs were estimated by using a multiplier of Medicare costs. RESULTS: Over a 3-year period following revision THA, re-interventions were performed in 11 (9%) DM patients and 34 (19%) LFH patients, costing $263-$1898 in DM THAs and $1285-$3946 in LFH THAs for Medicare. When compared to LFH implants, DM constructs were less costly to Medicare and private payers, resulting in cost differentials of $1536 and $2611, respectively. CONCLUSIONS: At mid-term follow-up, DM constructs utilized in revision THAs were associated with 11% lower absolute risk of re-intervention and payer savings of $1500-$2500 per case when compared to LFH constructs. LEVEL OF EVIDENCE: Economic and decision analysis, Level III.

The Role of Crosslinked Polyethylene in Reducing Aggregated Costs of Total Hip Arthroplasty in the United States.

BACKGROUND: Widespread adoption of crosslinked polyethylene for the acetabular articular surface for total hip arthroplasty has substantially reduced revision rates and dislocation rates. We aim to provide estimates of the resulting magnitude of the annual reduction in aggregated costs of total hip arthroplasty surgery in the United States. METHODS: After we obtained, from the literature, the contrasting mid-term rates of revisions and dislocations of total hip arthroplasty using conventional polyethylene vs those using crosslinked polyethylene, specifically from only registry studies and prospective, randomized controlled studies, we multiplied these incidence figures by the cost estimates of these failures to generate approximations of the cost savings in the United States from the use of crosslinked polyethylene. RESULTS: The estimates suggest that in the United States these savings might be one billion dollars per annual cohort over a 15-year duration. CONCLUSION: The use of crosslinked polyethylene has reduced substantially the overall costs of total hip arthroplasty surgery in the United States.

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.

Value of External Data in the Extrapolation of Survival Data: A Study Using the NJR Data Set.

BACKGROUND: Extrapolation of time-to-event data can be a critical component of cost-effectiveness analysis. OBJECTIVES: To contrast the value of external data on treatment effects as a selection aid in model fitting to the clinical data or for the direct extrapolation of survival. METHODS: We assume the existence of external summary data on both treatment and control and consider two scenarios: availability of external individual patient data (IPD) on the control only and an absence of external IPD. We describe how the summary data can be used to extrapolate survival or to assess the plausibility of extrapolations of the clinical data. We assess the merit of either approach using a comparison of cemented and cementless total hip replacement as a case study. Merit is judged by comparing incremental net benefit (INB) obtained in scenarios with incomplete IPD with that derived from modeling external IPD on both treatment and control. RESULTS: Measures of fit with the external summary data did not identify survival model specifications that best estimated INB. Addition of external IPD for the control only did not improve estimates of INB. Extrapolation of survival using the external summary data comparing treatment and control improved estimates of INB. CONCLUSIONS: Our case study indicates that summary data comparing treatment and control are more valuable than IPD limited to the control when extrapolating event rates for cost-effectiveness analysis. These data are best exploited in direct extrapolation of event rates rather than as an aid to select extrapolations on the basis of the clinical data.

Are Ceramic Bearings Becoming Cost-Effective for All Patients?

BACKGROUND: The purpose of this study is to analyze whether the cost for ceramic-on-polyethylene (C-PE) and ceramic-on-ceramic (COC) bearings used in primary total hip arthroplasty (THA) was changing over time, and if the cost differential between ceramic bearings and metal-on-polyethylene (M-PE) bearings was approaching the previously published tipping point for cost-effectiveness of $325. METHODS: A total of 245,077 elderly Medicare patients (65+) who underwent primary THA between 2010 and 2015 were identified from the United States Medicare 100% national administrative hospital claims database. The inpatient hospital cost, calculated using cost-to-charge ratios, and hospital payment were analyzed. The differential cost of C-PE and COC bearings, compared to M-PE, were evaluated using parametric and nonparametric models. RESULTS: After adjustment for patient and clinical factors, and the year of surgery, the mean hospital cost and payments for primary THA with a C-PE or COC was within ±1% of the cost for primary THA with M-PE bearings (P < .001). From the nonparametric analysis, the median hospital cost was $318-$360 more for C-PE and COC than M-PE. The differential in median Medicare payment for THA with ceramic bearings compared to M-PE was <$100. Cost differentials were found to decrease significantly over time (P < .001). CONCLUSION: Patient and clinical factors had a far greater impact on the cost of inpatient THA surgery than bearing selection. Because we found that costs and cost differentials for ceramic bearings were decreasing over time, and approaching the tipping point, it is likely that the cost-effectiveness thresholds relative to M-PE are likewise changing over time and should be revisited in light of this study.

Revision Total Hip Arthroplasty-Reducing Hospital Cost Through Fixed Implant Pricing.

BACKGROUND: A large component of the cost of revision total hip arthroplasty (THA) is the cost of the implants. We examined the pricing of revision THA implants to determine the possible savings of different pricing models. METHODS: From our institutional database, all revision THAs done from 9/1/2013 to 8/31/2014 were identified. The cost of the implants was analyzed as a percentage of the total cost of the hospitalization and compared to direct to hospital and fixed implant pricing models. RESULTS: Of 153 revision THAs analyzed, the cost of implants amounted to 36% of the total hospital cost. The direct to hospital cost and fixed implant pricing models would reduce the cost of an all-component revision to $4395 (saving $8962 per case) and $5000 (saving $8357 per case). CONCLUSION: Both fixed implant pricing and the direct to hospital pricing models would result in a decrease in revision implant costs.

Custom-made triflanged acetabular components in the treatment of major acetabular defects. Short-term results and clinical experience.

We report on the Belgian experience with the aMace® custom-made triflange acetabular component in revision total hip arthroplasty between September 2009 and November 2014. We focused on (1) the complexity of the preoperative planning and reimbursement procedure; (2) the surgical problems and operative experience; and (3) the early outcome. We collected 20 patients' reviews and 22 surgeons' reviews, with a mean follow-up of 25 months. The preoperative planning and reimbursement procedures were rated as time-consuming and cumbersome. In 6/22 cases, the operation was difficult or very difficult. Technical problems occurred in 8/22 cases, including problematic fitting in four. However, all aMace® components could be implanted successfully. The mean postoperative Harris Hip Score (HHS) was 68/100; patients' satisfaction was high and most patients experienced no or mild pain. Complications occurred in 8/22 cases, half of them dislocations. The aMace® implant can provide a solution for complex acetabular revisions. As dislocations were common, the use of dual-mobility cups should be considered. Because of the high cost and the lack of bone stock restoration, we suggest using custom-made triflange acetabular implants only in cases with large cavitational and segmental defects, which would be difficult to reconstruct with alternative methods.

Economic Decision Model Suggests Total Shoulder Arthroplasty is Superior to Hemiarthroplasty in Young Patients with End-stage Shoulder Arthritis.

BACKGROUND: Young patients with severe glenohumeral arthritis pose a challenging management problem for shoulder surgeons. Two controversial treatment options are total shoulder arthroplasty (TSA) and hemiarthroplasty. This study aims to characterize costs, as expressed by reimbursements for episodes of acute care, and outcomes associated with each treatment. QUESTIONS/PURPOSES: We asked: for patients 30 to 50 years old with severe end-stage glenohumeral arthritis refractory to conservative management, (1) are more years of patient-derived satisfactory outcome by the Neer criteria and quality-adjusted life-years (QALYs) achieved using a TSA or a hemiarthroplasty; (2) does a TSA or a hemiarthroplasty result in a greater number of revision procedures; and (3) does a TSA or a hemiarthroplasty result in greater associated costs to society? METHODS: The incidence of glenohumeral arthritis among 30- to 50-year-old patients, outcomes, reoperation probabilities, and associated costs from TSA and hemiarthroplasty were derived from the literature. A Markov chain decision tree model was developed from these estimates with number of revisions, cost of management for patients to 70 years old as defined by reimbursement for acute-care episodes, years with "satisfactory" or "excellent" outcome by the modified Neer criteria, and QALYs gained as principle outcome measures. A Monte Carlo simulation was conducted with a cohort representing the at-risk population for shoulder arthritis between 30 and 50 years old in the United States. RESULTS: During the lifetime of a cohort of 5279 patients, hemiarthroplasty as the initial treatment resulted in 59,574 patient years of satisfactory or excellent results (11.29 per patient) and average QALYs gained of 6.55, whereas TSA as the initial treatment resulted in 85,969 patient years of satisfactory or excellent results (16.29 per patient) and average QALYs gained of 7.96. During the lifetime of a cohort of 5279 patients, a hemiarthroplasty as the initial treatment led to 2090 lifetime revisions (0.4 per patient), whereas a TSA as the initial treatment led to 1605 lifetime revisions (0.3 per patient). During the lifetime of a cohort of 5279 patients, a hemiarthroplasty as initial treatment resulted in USD 132,500,000 associated direct reimbursements (USD 25,000 per patient), whereas a TSA as initial treatment resulted in USD 125,500,000 associated direct reimbursements (USD 23,700 per patient). CONCLUSIONS: Treatment of end-stage glenohumeral arthritis refractory to conservative treatment in patients 30 to 50 years old in the United States with TSA, instead of hemiarthroplasty, would result in greater cost savings, avoid a substantial number of revision procedures, and result in greater years of satisfactory or excellent patient outcomes and greater QALYs gained. On a population level, TSA is the cost-effective treatment for glenohumeral arthritis in patients 30 to 50 years old. LEVEL OF EVIDENCE: Level II, economic and decision analysis study.

National Trends in Primary Total Hip Arthroplasty in Extremely Young Patients: A Focus on Bearing Surface Usage From 2009 to 2012.

BACKGROUND: The ideal bearing surface for primary total hip arthroplasty (THA) in young patients remains a debate. Data on recent national trends are lacking. The purpose of this study is to provide an analysis on the national epidemiologic trends of bearing surface usage in patients aged ≤30 years undergoing THA from 2009 through 2012. METHODS: Using the Healthcare Cost and Utilization Project Nationwide Inpatient Sample from 2009 to 2012, 9265 THA discharges (4210 coded by bearing surface) were identified in patients aged ≤30 years. Prevalence of surface type was analyzed along with patient and hospital demographic data. Statistical analysis was performed using SAS (SAS version 9.1; SAS, Inc, Cary, NC). Significance was set at P < .05. RESULTS: Ceramic-on-polyethylene (CoP) bearing surfaces were most commonly used, representing 35.6% of cases, followed by metal-on-polyethylene (MoP; 28.0%), metal-on-metal (MoM; 19.3%), and ceramic-on-ceramic (CoC; 17.0%) bearing surfaces. Hard-on-hard bearing surfaces (MoM and CoC) represented only 36.4% of cases, a significant decrease from previously reported findings (2006-2009) where hard-on-hard bearing surfaces were the majority (62.2%; P < .05). Hard-on-hard bearing surface usage decreased from 2009 to 2012 (MoM: 29.7% to 10.2%; CoC: 20.0% to 14.7%), whereas hard-on-soft bearing surface usage (MoP and CoP) increased. CoP bearing surfaces saw the most significant increase from 25.7% in 2009 to 48.2% in 2012. A cost analysis revealed that CoP discharges were associated with higher hospital charges than other surface types, with an average charge of $66,457 (P < .05). CONCLUSION: Use of hard-on-hard surfaces has decreased significantly in this population, whereas CoP and MoP surfaces have become increasingly common. Determining the optimal bearing surface for extremely young patients continues to be a challenge for orthopedic surgeons as they weigh the risks and benefits of each.

Constrained acetabular liners in hip revision surgery. A low-cost solution for senile patients.

The objective of this study was to analyze the results of a cemented polyethylene model that captures the hip prosthetic head. In a retrospective study we reviewed 36 cemented constrained acetabular liners implanted in patients older than 75 years (mean 83, SD : 4.4), of which 30 patients were aged 80-90 years and 26 were women. The average period of follow-up of our patients was 25.4 months (12-39 months, SD : 7.3). In 26 patients this model was implanted due to recurrent dislocation or instability, in 8 other cases this model was implanted during revision surgery for periprosthetic fractures, aseptic loosening of the -acetabular component, wear of the polyethylene or replacement of the implant because of infection. There was a single case of recurrent dislocation (2.8%). Cemented acetabular constrained liners are a good option in revision surgery in senile patients in which the femoral stem is firmly fixed to the bone.

Current status of cost utility analyses in total joint arthroplasty: a systematic review.

BACKGROUND: Total joint arthroplasty (TJA), although considered to be highly beneficial, is associated with substantial costs to the US healthcare system. Cost utility analysis has become an increasingly important means to objectively evaluate the value of a healthcare intervention from the perspective of both extending the quantity and improving the quality of life. Relatively little is known about the overall cost utility analysis evidence base in TJA. QUESTIONS/PURPOSES: The goals of this review were to (1) determine the cost utility of TJA interventions; (2) critically assess the quality of published US-based cost utility analyses using the Quality of Health Economic Studies instrument; and (3) determine what characteristics were common among studies receiving a high quality score. METHODS: A systematic review of the literature using the MEDLINE database was performed to compile findings and critically appraise US-based cost utility analysis studies for total hip and knee arthroplasty. Based on review of 676 identified articles, 23 studies were included. We used the Quality of Health Economic Studies instrument to assess study quality and one-sided Fisher's exact tests were applied to analyze the predictors of high-quality cost utility analysis. RESULTS: Very few studies compare the cost utility of TJA versus nonoperative intervention; however, the available evidence suggests that TJA can be cost-saving and is highly cost-effective compared with conservative management of end-stage arthritis. The majority of identified studies are focused on the cost utility of new implant technologies or comparisons among surgical alternatives. These studies suggest that the upfront costs associated with new technologies are cost-effective when there is a major reduction in a future cost. The quality of identified studies is quite high (Quality of Health Economic Studies Instrument score: mean 86.5; range, 63-100). National funding source (p = 0.095) and lifetime horizon for analysis (p = 0.07) correlate with high-quality evidence but do not reach significance. CONCLUSIONS: Over the past 15 years, there has been a major increase in the volume of cost utility analyses published in total hip and knee arthroplasty. The quality of cost utility analyses published during that period is good. As increasing attention is paid to value in US health care, more attention should be paid to understanding the cost utility of TJA compared with nonoperative treatment modalities. Future studies may also look to incorporate patient willingness to pay.

Short-term complications have more effect on cost-effectiveness of THA than implant longevity.

BACKGROUND: Outcomes research in THA has focused largely on long-term implant survivorship as a primary outcome and emphasized the development of new implant technologies. In contrast, strategies to improve short-term outcomes, such as the frequencies of periprosthetic joint infections and unplanned readmissions, have received less attention. QUESTIONS/PURPOSES: We asked whether reductions in periprosthetic joint infections and early readmissions would have greater influence on the net monetary benefit (a summation of lifetime cost and quality of life) for THA compared with equivalent reductions in aseptic loosening. METHODS: A Markov model was created using decision-analysis software with six health states and death to represent seven major potential outcomes of THA. We compared the effect of a 10% reduction in each of the following outcomes: (1) periprosthetic joint infection, (2) hospital readmission, and (3) aseptic loosening. Procedure costs (not charges) were derived from our hospital cost-accounting system. Probabilities were derived primarily from the Australian Orthopaedic Association National Joint Replacement Registry, and utilities were estimated from a previous study at our institution using the time trade-off method. The primary outcome of the study is the net monetary benefit, which combines the reductions in cost and improvement in health-related quality of life in a single metric. Quality of life is expressed in quality-adjusted life years (QALYs), which are calculated by multiplying the utility of a health state (ranging from 0 to 1) by the duration of time in the health state. The cost and QALYs are reported separately as secondary outcomes. One-way and multivariate sensitivity analyses were performed including a probabilistic sensitivity analysis to account for uncertainty in model inputs. RESULTS: The net monetary benefit for a 10% reduction in periprosthetic joint infections was USD 278 (95% CI, USD 239-295) per index procedure compared with USD 174 (95% CI, USD 150-185) and USD 113 (95% CI, USD 94-129) for reductions in aseptic loosening and early readmission, respectively. Compared with the base case, reductions in cost associated with a 10% reduction in periprosthetic joint infections, early readmissions, and aseptic loosening were USD 98, USD 93, and USD 75 per index procedure, respectively. The increase in QALYs for an equivalent reduction in periprosthetic joint infections, aseptic loosening, and early readmissions were 0.0036, 0.002, and 0.0004 QALYs, respectively. Results were most sensitive to age, baseline rate of readmission, periprosthetic joint infection, aseptic loosening, and the costs of readmission and revision THA. CONCLUSIONS: Strategies to reduce periprosthetic joint infections may have a greater effect on the cost and long-term effectiveness of THA than further enhancements in implant longevity. Reductions in the rate of readmission resulted in greater reductions in cost but not quality-of-life, and therefore had smaller effect on the net monetary benefit compared with aseptic loosening. Surgeons preferentially should engage in strategies focusing on periprosthetic joint infections to improve the value of THA care. LEVEL OF EVIDENCE: Level II, economic and decision analysis.

Acetate templating on digital images is more accurate than computer-based templating for total hip arthroplasty.

BACKGROUND: Templating is an important aspect of preoperative planning for total hip arthroplasty and can help determine the size and positioning of the prosthesis. Historically, templating has been performed using acetate templates over printed radiographs. As a result of the increasing use of digital imaging, surgeons now either obtain additional printed radiographs solely for templating purposes or use specialized digital templating software, both of which carry additional cost. QUESTIONS/PURPOSES: The purposes of this study was to compare acetate templating of digitally calibrated images on an LCD monitor to digital templating in terms of (1) accuracy; (2) reproducibility; and (3) time efficiency. METHODS: Acetate onlay templating was performed directly over digital radiographs on an LCD monitor and was compared with digital templating. Five separate observers participated in this study templating on 52 total hip arthroplasties. For the acetate templating, the digital images were magnified to the scaled reference on the templates provided by the manufacturer (ratio 1.2:1) before templating using a 25-mm marker as a reference. Both the acetate and digital templating results were then compared with the actual implanted components to determine accuracy. Interobserver and intraobserver variability was determined by an intraclass correlation coefficient. Observers recorded time to complete templating from the time of complete upload of patients' imaging onto the system to completion of templating. RESULTS: Both acetate and digital templates demonstrated moderate accuracy in predicting within one size of the eventual implanted acetabular cup (77% [199 of 260]; 70% [181 of 260], respectively; p = 0.050; 95% confidence interval [CI], 0.058-0.32), whereas acetate templating was better at predicting the femoral stem compared to digital templating (75% [195 of 260]; 60% [155 of 260], respectively; p < 0.001; 95% CI, 0.084-0.32). Acetate templating showed moderate to substantial interobserver agreement (cup intraclass correlation coefficient [ICC] = 0.55; 95% CI, 0.14-0.86; femoral ICC = 0.75; 95% CI, 0.39-0.95) and both methods showed almost perfect intraobserver agreement in reproducibility (acetate cup ICC = 0.82; 95% CI, 0.66-0.97; acetate femoral ICC = 0.86; 95% CI, 0.74-0.97; digital cup ICC = 0.82; 95% CI, 0.68-0.97; digital femoral ICC = 0.88; 95% CI, 0.77-1.0). Acetate templating could be performed more quickly (acetate mean 119 seconds; range, 37-220 seconds versus 154 seconds; range, 73-343 seconds; p < 0.001). CONCLUSIONS: Acetate onlay templating on digitally calibrated images can be a reliable substitute for digital templating using specialized software. It is quicker to perform and much less expensive. Hospitals and practices need not purchase expensive software, particularly at lower volume centers. LEVEL OF EVIDENCE: Level III, diagnostic study.

Utilization rates of hip arthroplasty in OECD countries.

BACKGROUND: Hip arthroplasty and revision surgery is growing exponentially in OECD countries, but rates vary between countries. METHODS: We extracted economic data and utilization rates data about hip arthroplasty done in OECD countries between 1990 and 2011. Absolute number of implantations and compound annual growth rates were computed per 100,000 population and for patients aged 65 years old and over and for patients aged 64 years and younger. RESULTS: In the majority of OECD countries, there has been a significant increase in the utilization of total hip arthroplasty in the last 10 years, but rates vary to a great extent: In the United States, Switzerland, and Germany the utilization rate exceeds 200/100,000 population whereas in Spain and Mexico rates are 102 and 8, respectively. There is a strong correlation between gross domestic product (GDP) and health care expenditures per capita with utilization rate. Utilization rates in all age groups have continued to rise up to present day. A seven fold higher growth rate was seen in patients aged 64 years and younger as compared to older patients. CONCLUSION: We observed a 38-fold variation in the utilization of hip arthroplasty among OECD countries, correlating with GDP and health care expenditures. Over recent years, there has been an increase in the utilization rate in most countries. This was particularly evident in the younger patients. Due to increasing life expectancy and the disproportionally high use of arthroplasty in younger patients we expect an exponential increase of revision rate in the future.

Fabrication of low-cost, cementless femoral stem 316L stainless steel using investment casting technique.

Total hip arthroplasty is a flourishing orthopedic surgery, generating billions of dollars of revenue. The cost associated with the fabrication of implants has been increasing year by year, and this phenomenon has burdened the patient with extra charges. Consequently, this study will focus on designing an accurate implant via implementing the reverse engineering of three-dimensional morphological study based on a particular population. By using finite element analysis, this study will assist to predict the outcome and could become a useful tool for preclinical testing of newly designed implants. A prototype is then fabricated using 316L stainless steel by applying investment casting techniques that reduce manufacturing cost without jeopardizing implant quality. The finite element analysis showed that the maximum von Mises stress was 66.88 MPa proximally with a safety factor of 2.39 against endosteal fracture, and micromotion was 4.73 µm, which promotes osseointegration. This method offers a fabrication process of cementless femoral stems with lower cost, subsequently helping patients, particularly those from nondeveloped countries.

Increased rates of periprosthetic joint infection in patients with cirrhosis undergoing total joint arthroplasty.

BACKGROUND: Total joint arthroplasty (TJA) is becoming more prevalent, with additional increases in procedure rates expected as the US population ages. Small series have suggested increased risk of periprosthetic joint infections in patients with liver cirrhosis after TJA. However, the rates of periprosthetic joint infections and use of TJA for patients with cirrhosis have not been evaluated on a larger scale. QUESTIONS/PURPOSES: The purposes of this study were to (1) measure the rate of periprosthetic joint infections after THAs and TKAs in patients with cirrhosis of the liver; (2) assess mortality, length of hospital stay, readmission rates, and other clinical factors among patients with cirrhosis who have had a TJA; and (3) evaluate the use of TJA in the United States among patients with liver cirrhosis during the past decade. METHODS: National and state-level databases were used to identify patients with and without liver cirrhosis who underwent TJAs. The rate of periprosthetic joint infections within 6 months was assessed using the Statewide Inpatient Database, which identified 306,946 patients undergoing THAs (0.3% with cirrhosis) and 573,840 patients undergoing TKAs (0.2% with cirrhosis). To evaluate trends in the use of TJAs, 16,634 patients with cirrhosis who underwent TJAs were identified from the Nationwide Inpatient Sample from 2000 to 2010. RESULTS: Periprosthetic joint infections after THA were more common in patients with cirrhosis for hip fracture (6.3% versus 1.1%; hazard ratio [HR], 5.8; p < 0.001) and nonhip fracture diagnoses (3.7% versus 0.7%; HR, 5.4; p < 0.001). Periprosthetic joint infections were more common after TKA in patients with cirrhosis (2.7% versus 0.8%; HR, 3.4; p < 0.001). Use of TJA increased faster for patients with cirrhosis than for patients without cirrhosis for THAs (140% versus 80%; p = 0.011) and TKAs (213% versus 128%; p < 0.001), and also increased faster than the general increase in use of TJAs. CONCLUSIONS: Periprosthetic joint infections were more common among patients with cirrhosis who had TJAs. Additionally, patients with cirrhosis had longer length of hospital stay, increased costs, and higher rates of mortality, readmission, and reoperation. Finally, national use of TJAs for patients with cirrhosis has increased during the past decade. LEVEL OF EVIDENCE: Level III, therapeutic study. See the Instructions for Authors for a complete description of levels of evidence.