Cost effectiveness of total hip arthroplasty in osteoarthritis

Cost-Utility Analysis of Total Ankle Replacement Compared with Ankle Arthrodesis for Patients Aged 50-85 Years with End-Stage Ankle Osteoarthritis: The TARVA Study

BACKGROUND

Patients with end-stage ankle osteoarthritis suffer from reduced mobility and quality of life and the main surgical treatments are total ankle replacement (TAR) and ankle fusion (AF).

OBJECTIVES

Our aim was to calculate the mean incremental cost per quality-adjusted life-year (QALY) of TAR compared with AF in patients with end-stage ankle osteoarthritis, over 52 weeks and over the patients' lifetime.

METHOD

We conducted a cost-utility analysis of 282 participants from 17 UK centres recruited to a randomised controlled trial (TARVA). QALYs were calculated using index values from EQ-5D-5L. Resource use information was collected from case report forms and self-completed questionnaires. Primary analysis was within-trial analysis from the National Health Service (NHS) and Personal Social Services (PSS) perspective, while secondary analyses were within-trial analysis from wider perspective and long-term economic modelling. Adjustments were made for baseline resource use and index values.

RESULTS

Total cost at 52 weeks was higher in the TAR group compared with the AF group, from the NHS and PSS perspective (mean adjusted difference £2539, 95% confidence interval [CI] £1142, £3897). The difference became very small from the wider perspective (£155, 95% CI -  £1947, £2331). There was no significant difference between TAR and AF in terms of QALYs (mean adjusted difference 0.02, 95% CI -  0.015, 0.05) at 52 weeks post-operation. The incremental cost-effectiveness ratio (ICER) was £131,999 per QALY gained 52 weeks post-operation. Long-term economic modelling resulted in an ICER of £4200 per QALY gained, and there is a 69% probability of TAR being cost effective at a cost-effectiveness threshold of £20,000 per QALY gained.

CONCLUSION

TAR does not appear to be cost effective over AF 52 weeks post-operation. A decision model suggests that TAR can be cost effective over the patients' lifetime but there is a need for longer-term prospectively collected data. Clinical trial registration ISRCTN60672307 and ClinicalTrials.gov NCT02128555.

Total ankle replacement versus ankle arthrodesis for patients aged 50-85 years with end-stage ankle osteoarthritis: the TARVA RCT

Background

We aimed to compare the clinical effectiveness, cost-effectiveness and complication rates of total ankle replacement with those of arthrodesis (i.e. ankle fusion) in the treatment of end-stage ankle osteoarthritis.

Methods

This was a pragmatic, multicentre, parallel-group, non-blinded randomised controlled trial. Patients with end-stage ankle osteoarthritis who were aged 50-85 years and were suitable for both procedures were recruited from 17 UK hospitals and randomised using minimisation. The primary outcome was the change in the Manchester-Oxford Foot Questionnaire walking/standing domain scores between the preoperative baseline and 52 weeks post surgery.

Results

Between March 2015 and January 2019, 303 participants were randomised using a minimisation algorithm: 152 to total ankle replacement and 151 to ankle fusion. At 52 weeks, the mean (standard deviation) Manchester-Oxford Foot Questionnaire walking/standing domain score was 31.4 (30.4) in the total ankle replacement arm (n = 136) and 36.8 (30.6) in the ankle fusion arm (n = 140); the adjusted difference in the change was -5.6 (95% confidence interval -12.5 to 1.4; p = 0.12) in the intention-to-treat analysis. By week 52, one patient in the total ankle replacement arm required revision. Rates of wound-healing issues (13.4% vs. 5.7%) and nerve injuries (4.2% vs. < 1%) were higher and the rate of thromboembolic events was lower (2.9% vs. 4.9%) in the total ankle replacement arm than in the ankle fusion arm. The bone non-union rate (based on plain radiographs) in the ankle fusion arm was 12.1%, but only 7.1% of patients had symptoms. A post hoc analysis of fixed-bearing total ankle replacement showed a statistically significant improvement over ankle fusion in Manchester-Oxford Foot Questionnaire walking/standing domain score (-11.1, 95% confidence interval -19.3 to -2.9; p = 0.008). We estimate a 69% likelihood that total ankle replacement is cost-effective compared with ankle fusion at the National Institute for Health and Care Excellence's cost-effectiveness threshold of £20,000 per quality-adjusted life-year gained over the patient's lifetime.

Limitations

This initial report contains only 52-week data, which must therefore be interpreted with caution. In addition, the pragmatic nature of the study means that there was heterogeneity between surgical implants and techniques. The trial was run across 17 NHS centres to ensure that decision-making streams reflected the standard of care in the NHS as closely as possible.

Conclusions

Both total ankle replacement and ankle fusion improved patients' quality of life at 1 year, and both appear to be safe. When total ankle replacement was compared with ankle fusion overall, we were unable to show a statistically significant difference between the two arms in terms of our primary outcome measure. The total ankle replacement versus ankle arthrodesis (TARVA) trial is inconclusive in terms of superiority of total ankle replacement, as the 95% confidence interval for the adjusted treatment effect includes both a difference of zero and the minimal important difference of 12, but it can rule out the superiority of ankle fusion. A post hoc analysis comparing fixed-bearing total ankle replacement with ankle fusion showed a statistically significant improvement of total ankle replacement over ankle fusion in Manchester-Oxford Foot Questionnaire walking/standing domain score. Total ankle replacement appears to be cost-effective compared with ankle fusion at the National Institute for Health and Care Excellence's cost-effectiveness threshold of £20,000 per quality-adjusted life-year gained over a patient's lifetime based on long-term economic modelling.

Future work

We recommend long-term follow-up of this important cohort, in particular radiological and clinical progress. We also recommend studies to explore the sensitivity of clinical scores to detect clinically important differences between arms when both have already achieved a significant improvement from baseline.

Trial registration

This trial is registered as ISRCTN60672307 and ClinicalTrials.gov NCT02128555.

Funding

This project was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 27, No. 5. See the NIHR Journals Library website for further project information.

Outcome measures in total hip arthroplasty: have our metrics changed over 15 years?

INTRODUCTION

Consensus has not been reached regarding ideal outcome measures for total hip arthroplasty (THA) clinical evaluation and research. The goal of this review was to analyze the trends in outcome metrics within the THA literature and to discuss the potential impact of instrument heterogeneity on clinical practice.

MATERIALS AND METHODS

A PubMed search of all manuscripts related to THA from January 2005 to December 2019 was performed. Statistical and linear regression analyses were performed for individual outcome metrics as a proportion of total THA publications over time.

RESULTS

There was a statistically significant increase in studies utilizing outcomes metrics between 2005 and 2019 (15.1-29.5%; P < 0.001; R² = 98.1%). Within the joint-specific subcategory, use of the Harris Hip Score (HHS) significantly decreased from 2005 to 2019 (82.8-57.3%; P < 0.001), use of the Hip Disability and Osteoarthritis Outcome Score (HOOS) significantly increased (0-6.7%; P < 0.001), and the modified HHS significantly increased (0-10.5%; P < 0.001). In the quality of life subcategory, EQ-5D demonstrated a significant increase in usage (0-34.8%; P < 0.001), while Short Form-36 significantly decreased (100% vs. 27.3%; P = 0.008).

CONCLUSIONS

The utilization of outcome-reporting metrics in THA has continued to increase, resulting in added complexity within the literature. The utilization rates of individual instruments have shifted over the past 15 years. Additional study is required to determine which specific instruments are recommended.

Blood loss and transfusion rates following total hip arthroplasty: a multivariate analysis

This study aimed to identify factors that inde- pendently predict increased rates of transfusion following total hip arthroplasty (THA) surgery. A retrospective analysis of all patients undergoing THA surgery over 12 months was performed. Electronic operative records were analysed to determine the following patient factors: American Society of Anesthesiologists (ASA) grade, body mass index (BMI), co-morbidities, indication for surgery, surgical technique, type of implant used, haematological markers, hospital length of stay (LOS) and complications. A total of 244 patients were included. There were 141 females (58%) and 103 males (42%). The median age was 65±12. The median pre-operative blood volume was 4500mls (IQR; 4000-5200). The median blood loss was 1069mls (IQR; 775-1390). The total number of patients requiring transfusion was 28 (11%), with a median of two units being transfused. Pre-operative haemoglobin (p<0.001) level, haematocrit (p<0.001) level and weight (p=0.016) were found to be predictive of transfusion requirement as well as ASA grade (p=0.005). Application of an intra-operative surgical drain was associated with higher rates of transfusion (p<0.001). Our study strengthens the evidence that pre-operative haemoglobin and haematocrit levels are valuable predictors of patients requiring transfusion. Additionally, ASA grade may be viewed as a helpful factor in predicting risk of transfusion. A strategy incorporating pre-operative optimisation of modifiable factors may reduce rates of transfusion requirement.

Should patient age thresholds dictate fixation strategy in total hip arthroplasty?

AIMS

Total hip arthroplasty (THA) is a very successful and cost-effective operation, yet debate continues about the optimum fixation philosophy in different age groups. The concept of the 'cementless paradox' and the UK 'Getting it Right First Time' initiative encourage increased use of cemented fixation due to purported lower revision rates, especially in elderly patients, and decreased cost.

METHODS

In a high-volume, tertiary referral centre, we identified 10,112 THAs from a prospectively collected database, including 1,699 cemented THAs, 5,782 hybrid THAs, and 2,631 cementless THAs. The endpoint was revision for any reason. Secondary analysis included examination of implant survivorship in patients aged over 70 years, over 75 years, and over 80 years at primary THA.

RESULTS

Cemented fixation had the lowest implant survival in all age groups, with a total ten-year survivorship of 97.0% (95% confidence interval (CI) 95.8 to 97.8) in the cemented group, 97.6% (95% CI 96.9 to 98.1) in the hybrid group, and 97.9% (95% CI 96.9 to 98.6) in the cementless group. This was not statistically significant (p = 0.092). There was no age group where cemented fixation outperformed hybrid or cementless fixation.

CONCLUSION

While all fixation techniques performed well at long-term follow-up, cemented fixation was associated with the lowest implant survival in all age groups, including in more elderly patients. We recommend that surgeons should carefully monitor their own outcomes and use fixation techniques that they are familiar with, and deliver the best outcomes in their own hands. Cite this article: Bone Joint J 2022;104-B(2):206-211.

Cost-effectiveness analyses comparing cemented, cementless, hybrid and reverse hybrid fixation in total hip arthroplasty: a systematic overview and critical appraisal of the current evidence

Background: This study aims to present an overview and critical appraisal of all previous studies comparing costs and outcomes of the different modes of fixation in total hip arthroplasty (THA). A secondary aim is to provide conclusions regarding the most cost-effective mode of implant fixation per gender and age-specific population in THA, based on high quality studies.Methods: A systematic search was conducted to identify cost-effectiveness analyses (CEAs) comparing different modes of implant fixation in THA. Analysis of results was done with solely CEAs that had a high methodological quality.Results: A total of 12 relevant studies were identified and presented, of which 5 were considered to have the methodological rigor for inclusion in the analysis of results. These studies found that either cemented or hybrid fixation was the most cost-effective implant fixation mode for most age- and gender-specific subgroups.Conclusion: Currently available well performed CEAs generally support the use of cemented and hybrid fixation for all age-groups relevant for THA and both genders. However, these findings were mainly based on a single database and depended on assumptions made in the studies' methodology. Issues discussed in this paper have to be considered and future work is needed.

Do custom 3D-printed revision acetabular implants provide enough value to justify the additional costs? The health-economic comparison of a new porous 3D-printed hip implant for revision arthroplasty of Paprosky type 3B acetabular defects and its closest alternative

PURPOSE

Total hip arthroplasty (THA) is a common operation for patients suffering from hip arthrosis. It has been proven effective in improving quality of life while being cost-effective. Meanwhile, the number of revision hip arthroplasty is growing and those may require bone reconstruction and are potential indications for 3D custom implants. In these specific indications, medical 3D-printing has grown over the years and the use of 3D-printed implants has become more frequent. To date, the cost-effectiveness of 3D-printed implants for acetabular revision THA has not been evaluated. Therefore we performed a health economic analysis to: (1) analyse the cost-effectiveness of the aMace implant compared to its closest alternative on the market, (2) have a better insight into Belgian costs of revision hip arthroplasties and (3) estimate the budget impact in Belgium.

HYPOTHESIS

3D-printed acetabular implants provide good value-for-health in Paprosky type 3B defects in a Belgian setting.

MATERIAL AND METHODS

Custom Three-flanged Acetabular Components (CTAC) were compared to a 3D-printed implant (aMace) by means of a Markov model with four states (successful, re-revision, resection and dead). The cycle length was set at 6 months with a 10-year time horizon. Data was obtained through systematic literature search and provided by a large social security agency. The analysis was performed from a societal perspective. All amounts are displayed in 2019 euros. Discount rates were applied for future cost (3%) and QALY (1.5%) estimates.

RESULTS

Revision hip arthroplasty has an average societal cost of €9950 without implant. Based on the outcomes of our model, aMace provides an excellent value for money compared to CTAC. The Incremental Cost-Effectiveness Ratio (ICER) was negative for all age groups. The base case of a 65 year old person, showed a QALY gain of 0.05 with a cost reduction of €1265 compared to CTAC. The advantage of using aMace was found to be greater if a patient is younger. The re-revision rates of both CTAC and aMace and the utility of successful revision have the highest impact on costs and effects. A Monte Carlo simulation showed aMace to be a cost-effective strategy in 90% of simulations for younger patients and in 88% of simulations for patients above 85 years old. In Belgium it would imply a cost reduction of €20500 on an annual basis.

CONCLUSIONS

Based on the findings of this model, the new 3D-printed aMace implant has the potential to bring an excellent value for money when used in revision arthroplasty of Paprosky type 3B acetabular defects. For all patients, aMace resulted in a dominant, cost-saving strategy in Belgium compared to CTAC.

LEVEL OF EVIDENCE

III, comparative medico economical diagnostic tool.

Cost effectiveness analyses of total hip arthroplasty for hip osteoarthritis: A PRISMA systematic review

BACKGROUND

Healthcare services are facing economic constraints globally with an increasingly elderly population, and greater burdens of osteoarthritis. Because of the chronic nature of osteoarthritis and the costs associated with surgery, arthroplasty is seen as potentially cost saving. There have been no systematic reviews conducted on cost effectiveness analysis (CEA) studies of total hip arthroplasty (THA) in the management of osteoarthritis. The aim of this systematic review was to evaluate CEAs conducted on THA for osteoarthritis to determine if THA is a cost-effective intervention.

MATERIALS AND METHODS

A systematic review was conducted using five databases to identify all clinical CEAs of THA for osteoarthritis conducted after 1 January 1997. Twenty-eight studies were identified that met the inclusion criteria. The Quality of Health Economic Analysis (QHES) checklist was employed to assess the quality of the studies.

RESULTS

The average QHES score was 86 indicating high quality studies. All studies reviewed concluded that THA was a cost-effective intervention. In younger patients, cementless THA and ceramic on polyethylene implants were found to be most cost effective. Hybrid THA and metal on polyethylene implants had the greatest cost utility in older patients. In patients with acetabular defects, cemented cup with impaction bone grafting was most cost effective, while dual mobility THA was most cost effective in patients with high risk of dislocation.

CONCLUSION

We have shown that THA is a cost-effective treatment for hip osteoarthritis. These findings should be implemented into clinical practice to improve cost utility in health services across the world.

How Are We Measuring Cost-Effectiveness in Total Joint Arthroplasty Studies? Systematic Review of the Literature

BACKGROUND

As volumes of total hip arthroplasty (THA) and total knee arthroplasty (TKA) continue to rise, it is important to understand their economic impact. No systematic review on cost-effectiveness of THA/TKA has been performed since 2016 despite recent changes in the healthcare environment. The purpose of the study is to provide a contemporary analysis of the cost-effectiveness of total joint arthroplasty and the use of quality-adjusted life years (QALYs).

METHODS

A systematic review was performed from 2005 to 2020. Online databases (OVID Medline, PubMed, Cost-Effectiveness Analysis Registry, Google Scholar, Elton B. Stephens Co) were queried to identify economic analyses that evaluated the cost-effectiveness of THA/TKA.

RESULTS

In total, 38 studies met the screening criteria. Study designs were primarily Markov models (68%), cohort studies (16%), and randomized trials (8%). Most studies adopted either a societal perspective (45%) or a health system perspective (39%). Analysis revealed that THA/TKA was strongly cost-effective compared to nonsurgical treatment. THA/TKA procedures that were not delayed were more cost-effective than delayed intervention. The majority of studies used QALYs as the primary quality metric (82%); in all these studies there was a significant improvement in QALYs gained.

CONCLUSION

Given the high economic impact of arthroplasty, ongoing assessment of cost-effectiveness is needed. Twenty-four percent of studies included in this systematic review were published in the last 4 years of this 15-year study period, highlighting the need for continuous assessment of aggregate data. Future studies should incorporate the cost-effectiveness of THA and TKA with respect to the work-value provided by surgeon providers to support health policy and reimbursement.

The Arthroplasty Candidacy Help Engine tool to select candidates for hip and knee replacement surgery: development and economic modelling

BACKGROUND

There is no good evidence to support the use of patient-reported outcome measures (PROMs) in setting preoperative thresholds for referral for hip and knee replacement surgery. Despite this, the practice is widespread in the NHS.

OBJECTIVES/RESEARCH QUESTIONS

Can clinical outcome tools be used to set thresholds for hip or knee replacement? What is the relationship between the choice of threshold and the cost-effectiveness of surgery?

METHODS

A systematic review identified PROMs used to assess patients undergoing hip/knee replacement. Their measurement properties were compared and supplemented by analysis of existing data sets. For each candidate score, we calculated the absolute threshold (a preoperative level above which there is no potential for improvement) and relative thresholds (preoperative levels above which individuals are less likely to improve than others). Owing to their measurement properties and the availability of data from their current widespread use in the NHS, the Oxford Knee Score (OKS) and Oxford Hip Score (OHS) were selected as the most appropriate scores to use in developing the Arthroplasty Candidacy Help Engine (ACHE) tool. The change in score and the probability of an improvement were then calculated and modelled using preoperative and postoperative OKS/OHSs and PROM scores, thereby creating the ACHE tool. Markov models were used to assess the cost-effectiveness of total hip/knee arthroplasty in the NHS for different preoperative values of OKS/OHSs over a 10-year period. The threshold values were used to model how the ACHE tool may change the number of referrals in a single UK musculoskeletal hub. A user group was established that included patients, members of the public and health-care representatives, to provide stakeholder feedback throughout the research process.

RESULTS

From a shortlist of four scores, the OHS and OKS were selected for the ACHE tool based on their measurement properties, calculated preoperative thresholds and cost-effectiveness data. The absolute threshold was 40 for the OHS and 41 for the OKS using the preferred improvement criterion. A range of relative thresholds were calculated based on the relationship between a patient's preoperative score and their probability of improving after surgery. For example, a preoperative OHS of 35 or an OKS of 30 translates to a 75% probability of achieving a good outcome from surgical intervention. The economic evaluation demonstrated that hip and knee arthroplasty cost of < £20,000 per quality-adjusted life-year for patients with any preoperative score below the absolute thresholds (40 for the OHS and 41 for the OKS). Arthroplasty was most cost-effective for patients with lower preoperative scores.

LIMITATIONS

The ACHE tool supports but does not replace the shared decision-making process required before an individual decides whether or not to undergo surgery.

CONCLUSION

The OHS and OKS can be used in the ACHE tool to assess an individual patient's suitability for hip/knee replacement surgery. The system enables evidence-based and informed threshold setting in accordance with local resources and policies. At a population level, both hip and knee arthroplasty are highly cost-effective right up to the absolute threshold for intervention. Our stakeholder user group felt that the ACHE tool was a useful evidence-based clinical tool to aid referrals and that it should be trialled in NHS clinical practice to establish its feasibility.

FUTURE WORK

Future work could include (1) a real-world study of the ACHE tool to determine its acceptability to patients and general practitioners and (2) a study of the role of the ACHE tool in supporting referral decisions.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Systematic Review of the Evolution of Health-Economic Evaluation Models of Osteoarthritis

OBJECTIVE

To comprehensively synthesize the evolution of health-economic evaluation models (HEEMs) of all osteoarthritis (OA) interventions, including preventions, core treatments, adjunct nonpharmacologic interventions, pharmacologic interventions, and surgical treatments.

METHODS

The literature was searched within health-economic/biomedical databases. Data extracted included OA type, population characteristics, model setting/type/events, study perspective, and comparators; the reporting quality of the studies was also assessed. The review protocol was registered at the International Prospective Register of Systematic Reviews (CRD42018092937).

RESULTS

Eighty-eight studies were included. Pharmacologic and surgical interventions were the focus in 51% and 44% of studies, respectively. Twenty-four studies adopted a societal perspective (with increasing popularity after 2013), but most (63%) did not include indirect costs. Quality-adjusted life years was the most popular outcome measure since 2008. Markov models were used by 62% of studies, with increasing popularity since 2008. Until 2010, most studies used short-to-medium time horizons; subsequently, a lifetime horizon became popular. A total of 86% of studies reported discount rates (predominantly between 3% and 5%). Studies published after 2002 had a better coverage of OA-related adverse events (AEs). Reporting quality significantly improved after 2001.

CONCLUSION

OA HEEMs have evolved and improved substantially over time, with the focus shifting from short-to-medium-term pharmacologic decision-tree models to surgical-focused lifetime Markov models. Indirect costs of OA are frequently not considered, despite using a societal perspective. There was a lack of reporting sensitivity of model outcome to input parameters, including discount rate, OA definition, and population parameters. While the coverage of OA-related AEs has improved over time, it is still not comprehensive.

Robotic-Arm Assisted Direct Anterior Total Hip Arthroplasty; Improving Implant Accuracy

INTRODUCTION

The aim of this study was to investigate the accuracy of implant position of robotic-arm assisted total hip arthroplasty (THA) via the direct anterior approach (DAA).

MATERIALS AND METHODS

All patients who underwent robotic-arm assisted DAA THA (MAKO Surgical Corp., Ft. Lauderdale, Florida) from November 2018 to January 2020 were prospectively followed up. Pelvis indices (limb length discrepancy, femoral and hip offset, implant inclination, and anteversion), surgical duration, length of stay, and complications were recorded. To further evaluate the accuracy of robotic-arm assisted THA, patients who underwent manual DAA THA by the same surgeon were match-paired with the study group.

RESULTS

Twenty-five patients underwent robotic-arm assisted DAA THR. Limb length discrepancy was restored to 0.1mm (±3.4mm) from 10.0mm (±6.4mm) postoperatively. Preoperatively, the difference in femoral offset was 5.1mm (±5.1mm), and this was corrected to 1.9mm (±6.5mm) postoperatively. Nine cases had target inclination of 40° and mean inclination achieved was 40.7° (±0.9°). Sixteen cases had target inclination of 45° and mean inclination achieved was 45.3° (±1.0°). Mean anteversion was 19.5° (±2.4°). Propensity matched analysis showed that the root mean square errors for manual cup implantation compared to the robotic-arm assisted group was 2.3 times higher for anteversion and 6.3 times higher for inclination. Fourteen (56%) of the cups were within Callanan safe-zone and 18 (72%) within Lewinnek safe-zone in the manual group compared to 18 (72%) and 25 (100%), respectively, in the robotic-arm assisted group.

CONCLUSION

Combining the muscle-sparing technique of DAA with the improved implant placement with the robotic-arm assisted platform is a promising solution to improving THA outcomes.

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.

Perioperative Complication Rates in Pediatric Total Joint Arthroplasty Patients Compared With Adults: Results of a Matched Cohort Study

BACKGROUND

One of the least studied areas in orthopaedics is total joint arthroplasty (TJA) in pediatric patients. Recent studies have confirmed that these procedures are being performed on pediatric patients, making it critical to understand the rates of surgical complications in this patient population. We sought to examine the frequency in which surgical complications occur in pediatric patients, aged 20 and younger, undergoing TJA compared with adults.

METHODS

Data from the 2003 to 2012 Kids' Inpatient Database (ages 20 and younger) and 2002 to 2013 National Inpatient Sample (ages 21 and over) were analyzed. Pediatric patients were matched to 3 adult controls (1 per age group: 21 to 50, 51 to 65, and over 65 y) using patient characteristics including sex, race, orthopaedic diagnosis, and preoperative loss of function. Comparisons were then made between the rates and relative risks (RRs) of surgical complications between pediatric and adult patients. Finally, we examined patient factors associated with surgical complications, utilizing modified Poisson regression models with robust SEs.

RESULTS

Three adult controls (ie, 1 control from each age group) were identified for 1385 pediatric patients, for a total sample of 5540 TJA patients. Approximately 10% of pediatric patients experienced either major or minor surgical complications. The overall rate of major complications in pediatric patients was 5.05%, compared with 4.79% in adult controls [RR: 1.06 (0.81 to 1.38), P=0.69]. The overall rate of minor complications in pediatric patients was 5.78%, compared with 5.68% in adult controls [RR: 1.02 (0.80 to 1.30), P=0.78]. When adjusted for patient demographics, the RR of major complications was 49% higher in pediatric patients compared with ages 21 to 50 [RR: 1.49 (1.03 to 2.16), P=0.03] with no statistically significant differences noted for other age groups. For minor complications, the adjusted RR in pediatric patients, compared with any other age group, did not approach statistical significance.

CONCLUSIONS

Pediatric patients undergoing TJA experience major and minor surgical complications at rates comparable with their adult counterparts. Our findings offer important insight on the rates of surgical complications in pediatric TJA patients, which is valuable for preoperative education and consultation with patients and families.

LEVEL OF EVIDENCE

Level III-therapeutic.

Handling the procurement of prostheses for total hip replacement: description of an original value based approach and application to a real-life dataset reported in the UK

OBJECTIVES

In most European countries, innovative medical devices are not managed according to cost-utility methods, the reason being that national agencies do not generally evaluate these products. The objective of our study was to investigate the cost-utility profile of prostheses for hip replacement and to calculate a value-based score to be used in the process of procurement and tendering for these devices.

METHODS

The first phase of our study was aimed at retrieving the studies reporting the values of QALYs, direct cost, and net monetary benefit (NMB) from patients undergoing total hip arthroplasty (THA) with different brands of hip prosthesis. The second phase was aimed at calculating, on the basis of the results of cost-utility analysis, a tender score for each device (defined according to standard tendering equations and adapted to a 0-100 scale). This allowed us to determine the ranking of each device in the simulated tender.

RESULTS

We identified a single study as the source of information for our analysis. Nine device brands (cemented, cementless, or hybrid) were evaluated. The cemented prosthesis Exeter V40/Elite Plus Ogee, the cementless device Taperloc/Exceed, and the hybrid device Exeter V40/Trident had the highest NMB (£152 877, £156 356, and £156 210, respectively) and the best value-based tender score.

CONCLUSIONS

The incorporation of value-based criteria in the procurement process can contribute to optimising the value for money for THA devices. According to the approach described herein, the acquisition of these devices does not necessarily converge on the product with the lowest cost; in fact, more costly devices should be preferred when their increased cost is offset by the monetary value of the increased clinical benefit.

Do higher-volume hospitals provide better value in revision hip and knee arthroplasty?

AIMS

The purpose of this study is to determine if higher volume hospitals have lower costs in revision hip and knee arthroplasty.

MATERIALS AND METHODS

We questioned the Centres for Medicare and Medicaid Services (CMS) Inpatient Charge Data and identified 789 hospitals performing a total of 29 580 revision arthroplasties in 2014. Centres were dichotomised into high-volume (performing over 50 revision cases per year) and low-volume. Mean total hospital-specific charges and inpatient payments were obtained from the database and stratified based on Diagnosis Related Group (DRG) codes. Patient satisfaction scores were obtained from the multiyear CMS Hospital Compare database.

RESULTS

High-volume hospitals comprised 178 (30%) of the total but performed 15 068 (51%) of all revision cases, including 509 of 522 (98%) of the most complex DRG 466 cases. While high-volume hospitals had higher Medicare inpatient payments for DRG 467 ($21 458 versus $20 632, p = 0.038) and DRG 468 ($17 003 versus $16 120, p = 0.011), there was no difference in hospital specific charges between the groups. Higher-volume facilities had a better CMS hospital star rating (3.63 versus 3.35, p < 0.001). When controlling for hospital geographic and demographic factors, high-volume revision hospitals are less likely to be in the upper quartile of inpatient Medicare costs for DRG 467 (odds ratio (OR) 0.593, 95% confidence intervals (CI) 0.374 to 0.941, p = 0.026) and DRG 468 (OR 0.451, 95% CI 0.297 to 0.687, p < 0.001).

CONCLUSION

While a high-volume hospital is less likely to be a high cost outlier, the higher mean Medicare reimbursements at these facilities may be due to increased case complexity. Further study should focus on measures for cost savings in revision total joint arthroplasties. Cite this article: Bone Joint J 2017;99-B:1611-17.

Cost-effectiveness of surgical interventions for the management of osteoarthritis: a systematic review of the literature

Background

The primary purpose of this study is to assess the existing evidence on the cost-effectiveness of surgical interventions for the management of knee and hip osteoarthritis by systematically reviewing published economic evaluation studies.

Methods

A systematic review was conducted for the period 2004 to 2016. Electronic databases were searched to identify both trial and model based economic evaluation studies that evaluated surgical interventions for knee and hip osteoarthritis.

Results

A total of 23 studies met the inclusion criteria and an assessment of these studies showed that total knee arthroplasty (TKA), and total hip arthroplasty (THA) showed evidence of cost-effectiveness and improvement in quality of life of the patients when compared to non-operative and non-surgical procedures. On the other hand, even though delaying TKA and THA may lead to some cost savings in the short-run, the results from the study showed that this was not a cost-effective option.

Conclusions

TKA and THA are cost-effective and should be recommended for the management of patients with end stage/severe knee and hip OA. However, there needs to be additional studies to assess the cost-effectiveness of other surgical interventions in order for definite conclusions to be reached.

Electronic supplementary material

The online version of this article (doi:10.1186/s12891-017-1540-2) contains supplementary material, which is available to authorized users.

ORIF or Arthroplasty for Displaced Femoral Neck Fractures in Patients Younger Than 65 Years Old: An Economic Decision Analysis

BACKGROUND

The decision between open reduction and internal fixation (ORIF) and arthroplasty for a displaced femoral neck fracture in a patient ≤65 years old can be challenging. Both options have potential drawbacks; if a fracture treated with ORIF fails to heal it may require a revision operation, whereas a relatively young patient who undergoes arthroplasty may need revision within his/her lifetime. The purpose of this study was to employ decision analysis modeling techniques to generate evidence-based treatment recommendations in this clinical scenario.

METHODS

A Markov decision analytic model was created to simulate outcomes after ORIF, total hip arthroplasty (THA), or hemiarthroplasty in patients who had sustained a displaced femoral neck fracture between the ages of 40 and 65 years. The variables in the model were populated with values from studies with high-level evidence and from national registry data reported in the literature. The model was used to estimate the threshold age above which THA would be the superior strategy. Results were tested using sensitivity analysis and probabilistic statistical analysis.

RESULTS

THA was found to be a cost-effective option for a displaced femoral neck fracture in an otherwise healthy patient who is >54 years old, a patient with mild comorbidity who is >47 years old, and a patient with multiple comorbidities who is >44 years old. The average clinical outcomes of THA and ORIF were similar for patients 40 to 65 years old, although ORIF had a wider variability in outcomes based on the success or failure of the initial fixation. For all ages and cases, hemiarthroplasty was associated with worse outcomes and higher costs.

CONCLUSIONS

Compared with ORIF, primary THA can be a cost-effective treatment for displaced femoral neck fractures in patients 45 to 65 years of age, with the age cutoff favoring THA decreasing as the medical comorbidity and risk of ORIF fixation failure increase. Hemiarthroplasty has worse outcomes at higher costs and is not recommended in this age group.

LEVEL OF EVIDENCE

Economic and decision analysis Level III. See Instructions for Authors for a complete description of levels of evidence.

Surgery for degenerative cervical myelopathy: a patient-centered quality of life and health economic evaluation

BACKGROUND CONTEXT

Degenerative cervical myelopathy (DCM) represents the most common cause of non-traumatic spinal cord impairment in adults. Surgery has been shown to improve neurologic symptoms and functional status, but it is costly. As sustainability concerns in the field of health care rise, the value of care has come to the forefront of policy decision-making. Evidence for both health-related quality of life outcomes and financial expenditures is needed to inform resource allocation decisions.

PURPOSE

This study aimed to estimate the lifetime incremental cost-utility of surgical treatment for DCM.

DESIGN/SETTING

This is a prospective observational cohort study at a Canadian tertiary care facility.

PATIENT SAMPLE

We recruited all patients undergoing surgery for DCM at a single center between 2005 and 2011 who were enrolled in either the AOSpine Cervical Spondylotic Myelopathy (CSM)-North America study or the AOSpine CSM-International study.

OUTCOME MEASURES

Health utility was measured at baseline and at 6, 12, and 24 months following surgery using the Short Form-6D (SF-6D) health utility score. Resource expenditures were calculated on an individual level, from the hospital payer perspective over the 24-month follow-up period. All costs were obtained from a micro-cost database maintained by the institutional finance department and reported in Canadian dollars, inflated to January 2015 values.

METHODS

Quality-adjusted life year (QALY) gains for the study period were determined using an area under the curve calculation with a linear interpolation estimate. Lifetime incremental cost-to-utility ratios (ICUR) for surgery were estimated using a Markov state transition model. Structural uncertainty arising from lifetime extrapolation and the single-arm cohort design of the study were accounted for by constructing two models. The first included a highly conservative assumption that individuals undergoing nonoperative management would not experience any lifetime neurologic decline. This constraint was relaxed in the second model to permit more general parameters based on the established natural history. Deterministic and probabilistic sensitivity analyses were employed to account for parameter uncertainty. All QALY gains and costs were discounted at a base of 3% per annum. Statistical significance was set at the .05 level.

RESULTS

The analysis included 171 patients; follow-up was 96.5%. Mean age was 58.2±12.0 years and baseline health utility was 0.56±0.14. Mean QALY gained over the 24-month study period was 0.139 (95% confidence interval: 0.109-0.170, p<.001) and the mean 2-year cost of treatment was $19,217.82±12,404.23. Cost associated with the operation comprised 65.7% of the total. The remainder was apportioned over presurgical preparation and postsurgical recovery. Three patients required a reoperation over the 2-year follow-up period. The costs of revision surgery represented 1.85% of the total costs. Using the conservative model structure, the estimated lifetime ICUR of surgical intervention was $20,547.84/QALY gained, with 94.7% of estimates falling within the World Health Organization definition of "very cost-effective" ($54,000 CAD). Using the more general model structure, the estimated lifetime ICUR of surgical intervention was $11,496.02/QALY gained, with 97.9% of estimates meeting the criteria to be considered "very cost-effective."

CONCLUSIONS

Surgery for DCM is associated with a significant quality of life improvement. The intervention is cost-effective and, from the perspective of the hospital payer, should be supported.

Has Metal-On-Metal Resurfacing Been a Cost-Effective Intervention for Health Care Providers?-A Registry Based Study

Background

Total hip replacement for end stage arthritis of the hip is currently the most common elective surgical procedure. In 2007 about 7.5% of UK implants were metal-on-metal joint resurfacing (MoM RS) procedures. Due to poor revision performance and concerns about metal debris, the use of RS had declined by 2012 to about a 1% share of UK hip procedures. This study estimated the lifetime cost-effectiveness of metal-on-metal resurfacing (RS) procedures versus commonly employed total hip replacement (THR) methods.

Methodology/Principal Findings

We performed a cost-utility analysis using a well-established multi-state semi-Markov model from an NHS and personal and social services perspective. We used individual patient data (IPD) from the National Joint Registry (NJR) for England and Wales on RS and THR surgery for osteoarthritis recorded from April 2003 to December 2012. We used flexible parametric modelling of NJR RS data to guide identification of patient subgroups and RS devices which delivered revision rates within the NICE 5% revision rate benchmark at 10 years. RS procedures overall have an estimated revision rate of 13% at 10 years, compared to <4% for most THR devices. New NICE guidance now recommends a revision rate benchmark of <5% at 10 years. 60% of RS implants in men and 2% in women were predicted to be within the revision benchmark. RS devices satisfying the 5% benchmark were unlikely to be cost-effective compared to THR at a standard UK willingness to pay of £20,000 per quality-adjusted life-year. However, the probability of cost effectiveness was sensitive to small changes in the costs of devices or in quality of life or revision rate estimates.

Conclusion/Significance

Our results imply that in most cases RS has not been a cost-effective resource and should probably not be adopted by decision makers concerned with the cost effectiveness of hip replacement, or by patients concerned about the likelihood of revision, regardless of patient age or gender.

The manufacture of generic replicas of implants for arthroplasty of the hip and knee

Joint replacement of the hip and knee remain very satisfactory operations. They are, however, expensive. The actual manufacturing of the implant represents only 30% of the final cost, while sales and marketing represent 40%. Recently, the patents on many well established and successful implants have expired. Companies have started producing and distributing implants that purport to replicate existing implants with good long-term results.

The aims of this paper are to assess the legality, the monitoring and cost saving implications of such generic implants. We also assess how this might affect the traditional orthopaedic implant companies.

Cite this article: Bone Joint J 2016;98-B:892–900.

Implant Optimisation for Primary Hip Replacement in Patients over 60 Years with Osteoarthritis: A Cohort Study of Clinical Outcomes and Implant Costs Using Data from England and Wales

BACKGROUND

Hip replacement is one of the most commonly performed surgical procedures worldwide; hundreds of implant configurations provide options for femoral head size, joint surface material and fixation method with dramatically varying costs. Robust comparative evidence to inform the choice of implant is needed. This retrospective cohort study uses linked national databases from England and Wales to determine the optimal type of replacement for patients over 60 years undergoing hip replacement for osteoarthritis.

METHODS AND FINDINGS

Implants included were the commonest brand from each of the four types of replacement (cemented, cementless, hybrid and resurfacing); the reference prosthesis was the cemented hip procedure. Patient reported outcome scores (PROMs), costs and risk of repeat (revision) surgery were examined. Multivariable analyses included analysis of covariance to assess improvement in PROMs (Oxford hip score, OHS, and EQ5D index) (9159 linked episodes) and competing risks modelling of implant survival (79,775 procedures). Cost of implants and ancillary equipment were obtained from National Health Service procurement data.

RESULTS

EQ5D score improvements (at 6 months) were similar for all hip replacement types. In females, revision risk was significantly higher in cementless hip prostheses (hazard ratio, HR = 2.22, p<0.001), when compared to the reference hip. Although improvement in OHS was statistically higher (22.1 versus 20.5, p<0.001) for cementless implants, this small difference is unlikely to be clinically important. In males, revision risk was significantly higher in cementless (HR = 1.95, p = 0.003) and resurfacing implants, HR = 3.46, p<0.001), with no differences in OHS. Material costs were lowest with the reference implant (cemented, range £1103 to £1524) and highest with cementless implants (£1928 to £4285). Limitations include the design of the study, which is intrinsically vulnerable to omitted variables, a paucity of long-term implant survival data (reflecting the duration of data collection), the possibility of revision under-reporting, response bias within PROMs data, and issues associated with current outcome scoring systems, which may not accurately reflect level of improvement in some patients.

CONCLUSIONS

Cement fixation, using a polyethylene cup and a standard sized head offers good outcomes, with the lowest risks and at the lowest costs. The most commonly used cementless and resurfacing implants were associated with higher risk of revision and were more costly, while perceptions of improved function and longevity were unsupported.