A cost-effectiveness analysis of total hip arthroplasty for osteoarthritis of the hip

Impact of body mass on hospital resource use in total hip arthroplasty

Objective

To determine the impact of BMI on post-operative outcomes and resource utilization following elective total hip arthroplasty (THA).

Design

A retrospective cohort analysis on all primary elective THA patients between 1996 and 2004. Primary outcomes investigated using regression analyses included length of stay (LOS) and costs (US dollars).

Setting

Mayo Clinic Rochester, a tertiary care centre.

Subjects

Patients were stratified by pre-operative BMI as normal (18·5–24·9 kg/m2), overweight (25·0–29·9 kg/m2), obese (30·0–34·9 kg/m2) and morbidly obese (≥35·0 kg/m2). Of 5642 patients, 1362 (24·1 %) patients had a normal BMI, 2146 (38·0 %) were overweight, 1342 (23·8 %) were obese and 792 (14·0 %) were morbidly obese.

Results

Adjusted LOS was similar among normal (4·99 d), overweight (5·00 d), obese (5·02 d) and morbidly obese (5·17 d) patients (P= 0·20). Adjusted overall episode costs were no different (P= 0·23) between the groups of normal ($17 211), overweight ($17 462), obese ($17 195) and morbidly obese ($17 655) patients. Overall operative and anaesthesia costs were higher in the morbidly obese group ($5688) than in normal ($5553), overweight ($5549) and obese ($5593) patients (P= 0·03). Operating room costs were higher in morbidly obese patients ($3418) than in normal ($3276), overweight ($3291) and obese ($3340) patients (P< 0·001). Post-operative costs were no different (P= 0·30). Blood bank costs differed (P= 0·002) and were lower in the morbidly obese group ($180) compared with the other patient groups (P< 0·05). Other differences in costs were not significant. Morbidly obese patients were more likely to be transferred to a nursing home (24·1 %) than normal (18·4 %), overweight (17·9 %) or obese (16·0 %) patients (P= 0·001 each). There were no differences in the composite endpoint of 30 d mortality, re-admissions, re-operations or intensive care unit utilization.

Conclusions

BMI in patients undergoing primary elective THA did not impact LOS or overall institutional acute care costs, despite higher operative costs in morbidly obese patients. Obesity does not increase resource utilization for elective THA.

A population-based nested case-control study of the costs of hip and knee replacement surgery

BACKGROUND

Studies of total joint arthroplasty (TJA) have not evaluated the costs and outcomes in the context of expected arthritis worsening.

OBJECTIVES

Using a cost-consequence approach, to examine changes in direct health care costs and arthritis severity after TJA for hip/knee arthritis compared with contemporaneous changes in matched controls.

RESEARCH DESIGN

Case control study nested in a population-based prospective cohort.

SUBJECTS

In a population cohort with disabling hip/knee osteoarthritis followed from 1996 to 2003, primary TJA recipients were matched with cohort nonrecipients on age, sex, region of residence, comorbidity, and inflammatory arthritis diagnosis.

MEASURES

Pre- and postoperative total and arthritis-attributable direct health care costs, arthritis severity, and general health status were compared for cases and matched controls.

RESULTS

Of 2109 participants with no prebaseline TJA, 185 cases received a single elective TJA during the follow-up period; of these, 183 cases and controls were successfully matched. Mean age was 71 years, 77.6% were female, 35.5% had > or =2 comorbidities, and 81.5% had > or =2 joints affected. At baseline, controls had less pain and disability and lower total and arthritis-attributable health care costs than cases. After surgery, although overall health care utilization was unchanged, cases experienced significant decreases in arthritis-attributable costs (mean decrease $278 including prescription drugs) and pain and disability (P < 0.0001 for all). Over the same time period, controls experienced a significant increase in total health care costs (mean increase $1978 including prescription drugs, P = 0.04) and no change or worsening of their arthritis status.

CONCLUSION

Compared with matched controls, arthroplasty is associated with significant reductions in pain, disability, and arthritis-attributable direct costs.

The final straw: a qualitative study to explore patient decisions to undergo total hip arthroplasty

BACKGROUND

Research focusing on the complex factors leading to patients decisions to replace their arthritic hip has been limited in favor of quantitative studies focusing on surgery outcomes. The purpose of this study was twofold: (1) to further explore patients experiences and their decision-making processes to undergo total hip arthroplasty and (2) to examine the factors that influenced patients decisions about the type of surgical procedure (approach, implants).

METHODS

In 2005, 18 patients who were either scheduled for an upcoming total hip arthroplasty or had completed total hip arthroplasty participated in semi-structured interviews (N = 9) or a focus group (N = 9) regarding their decision to undergo hip arthroplasty. The canons and procedures of the grounded theory approach to qualitative research guided the coding and content analysis of the data derived from the focus group and semi-structured interviews.

RESULTS

Three main categories or core concepts that emerged from the interviews and focus group were labeled (1) limitations, (2) psychological distress, and (3) perceptions about hip arthroplasty. These three categories yielded a total of ten subcategories. The participants in our study had lived with a hip arthritis to a point beyond which all decided to have hip replacement surgery ("the final straw"). Decisions to undergo surgery were based upon an increasing severity of limitations affecting their basic quality of daily living, relationships and psychological well-being. Participants acknowledged that their choice of surgeon, type of procedure and implants were largely based on their desire to choose a technique that minimized disruption to their muscles and led to a quick recovery. Having decided on the type of surgery, participants used colleagues, family, and the internet to identify the most qualified surgeons in their area.

CONCLUSION

Our study sheds further light on the complex process of patients "final straw" towards a total hip arthroplasty. Surgeons should be aware of patients personal processes in order to optimize their surgical experiences and outcomes. Future research should aim to resolve optimal approaches to arthroplasty in light of patients preferences for muscle-sparing and "minimally invasive" approaches.

Cost-outcome analysis of joint replacement: evidence from a Spanish public hospital

BACKGROUND AND OBJECTIVES

Efficiency-based healthcare decision-making has been widely accepted for some time, with cost per quality-adjusted life year (QALY) as the main outcome measure. Nevertheless, for numerous medical procedures, little data are available on the cost per QALY gained. The aim of the present study was to calculate the cost per QALY gained with primary hip and knee replacement and to compare the result with the cost per QALY for other medical procedures, as well as with the maximum threshold cost considered acceptable in Spain.

METHODS

We performed a prospective cohort pre-test/post-test study of patients undergoing primary hip or knee arthroplasty. Age, sex, and clinical variables were recorded. Functional status and quality of life were measured by means of the WOMAC and EuroQol instruments, respectively, before the intervention and 6 months later. The direct costs of the intervention were calculated, with length of hospital stay and the prosthesis as the main cost drivers.

RESULTS

A total of 80 patients, 40 from each intervention, were included in this study. Both functional and perceived health status improved after the intervention. The number of QALYs gained in the knee cohort was 4.64, while that in the hip cohort was 0.86. The total cost of knee replacement was lower (6,865.52 euro) than that of hip replacement (7,891.21 euro). The cost per QALY gained was 1,275.84 euro and 7,936.12 euro for knee and hip interventions, respectively. The calculations performed included a 6% discount rate for health outcomes, a 3% inflation rate for costs, and a success rate of 95% at 15 years.

CONCLUSIONS

The costs of both knee and hip replacement were lower than the threshold of 30,000 euro per QALY considered acceptable in Spain, and compared favorably with other medical and surgical procedures.

Early mortality after modern total hip arthroplasty

Because of improvements in surgical technique, anesthesia, and rehabilitation, mortality after hip arthroplasty may be on the decline. The purpose of this study was to determine the 90-day mortality rate after uncemented total hip arthroplasty (THA) performed under regional anesthesia. We retrospectively reviewed 7478 consecutive patients undergoing cementless primary or revision THA between January 2000 and July 2006. Patient survivorship was established and causes of death were obtained by accessing the Social Security Death Index, Centers for Disease Control and Prevention National Death Index, and State Departments of Vital Statistics. There were two intraoperative deaths from cardiac arrest. The overall 30- and 90-day mortality rates were 0.24% (18 of 7478) and 0.55% (41 of 7478), respectively. Thirty-day mortality after primary THA was low at 0.13% (eight of 6272). The most common cause of death was cardiovascular-related. Mortality after modern THA seems to have remained very low despite the availability of this procedure to patients of all ages and comorbidities.

LEVEL OF EVIDENCE

Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.

Optimal drug pricing, limited use conditions and stratified net benefits for Markov models of disease progression

Limited use conditions (LUCs) are a method of directing treatment with new drugs to those populations where they will be most cost effective. In this paper we investigate how a drug manufacturer could determine pricing and LUCs to maximize profits. We assume that the payer makes formulary decisions on the basis of net monetary benefits, that the disease can be modeled using a Markov model of disease progression, and that the drug reduces the probability of progression between states of the Markov model. LUCs are expressed as a range of probabilities of disease progression over which patients would have access to the new drug. We assume that the manufacturer determines the price and LUCs in order to maximize profits. We show that an explicit trade-off exists between the drug's price and the use conditions, that there is an upper bound on the drug price, that the proportion of the population targeted by the LUC does not depend on quality of life or costs in each health state or the payer's willingness to pay, and that high drug prices do not always correspond with high profits.

Athletic activity after total joint arthroplasty

Demand for total joint arthroplasty is projected to increase in the first three decades of the twenty-first century. With increasing frequency, patients who have a hip or knee replacement expect to, and choose to, participate in athletics following rehabilitation. In general, patients who have had a hip or knee replacement decrease their participation in, and intensity of, athletic activity following the total joint arthroplasty. The orthopaedic literature on athletic activity after total joint arthroplasty is limited to small retrospective studies with short-term follow-up. Expert opinion regarding appropriate athletic activity after total joint arthroplasty is available from the Hip Society and the Knee Society. When patients who have undergone joint replacements choose to participate in athletic activity, orthopaedic surgeons should provide information with which to evaluate the risk of sports activity and recommend appropriate athletic activity.

Habitual physical activity behavior of patients after primary total hip arthroplasty

BACKGROUND AND PURPOSE

Despite recognized health benefits of physical activity, little is known about the habitual physical activity behavior of patients after total hip arthroplasty (THA). The purpose of this study was to analyze this behavior and the fulfillment of guidelines for health-enhancing physical activity of these patients compared with a normative population.

SUBJECTS AND METHODS

The participants were 273 patients who had undergone a primary THA (minimum of 1 year postoperatively). Comparisons were made between this group and 273 age- and sex-matched individuals from a normative population. Comparisons also were made between participants with THA under 65 years of age and those 65 years of age and older and among participants with THA in different Charnley classes. Level of physical activity was assessed with the Short QUestionnaire to ASsess Health-enhancing physical activity (SQUASH).

RESULTS

No significant differences in total amount of physical activity or time spent in different categories of physical activity were found between the THA group and the normative group. Participants with THA spent significantly more minutes in activities of moderate intensity compared with the normative group. Participants with THA who were under 65 years of age were significantly more active than older participants with THA. Charnley class had significant effects on time spent at work, time spent in moderate-intensity activities, and total amount of activity, with the least activity performed by participants in Charnley class C. The guidelines were met by 51.2% of the participants with THA and 48.8% of the normative population. Female participants met the guidelines less frequently than male participants in both the combined groups (odds ratio=0.50, 95% confidence interval=0.35-0.72, P<.001) and the THA group (odds ratio=0.48, 95% confidence interval=0.28-0.80, P=.001).

DISCUSSION AND CONCLUSION

The results suggest that patients after THA are at least as physically active as a normative population. Nevertheless, a large percentage of these patients do not meet the guidelines; therefore, they need to be stimulated to become more physically active.

Cost-effectiveness analysis of periacetabular osteotomy

BACKGROUND

A lack of long-term outcomes data following periacetabular osteotomy makes it difficult for surgeons to recommend the most appropriate procedure to young patients who might be candidates for a joint-preserving procedure. In this study, we compared the cost-effectiveness of periacetabular osteotomy with total hip arthroplasty in terms of cost per quality-adjusted life year for the young adult.

METHODS

A decision model was constructed for a cost-utility analysis of periacetabular osteotomy compared with total hip arthroplasty. Outcome probabilities and effectiveness were derived from the literature. Effectiveness was expressed in quality-adjusted life years gained. Cost data were compiled and verified from our institution. Costs and utilities were discounted in accord with the United States Panel on Cost-Effectiveness in Health and Medicine. Principal outcome measures were average incremental costs, incremental effectiveness, incremental quality-adjusted life years, and net health benefits. Multivariate sensitivity analysis was used to assess the contribution of included variables in the model's outcomes.

RESULTS

For Tönnis grade-1 coxarthrosis, periacetabular osteotomy dominates with an average incremental cost-effectiveness of $7856 per quality-adjusted life year and an average incremental effectiveness of 0.15. For Tönnis grade-2 coxarthrosis, periacetabular osteotomy is, on the average, more cost-effective than total hip arthroplasty with an incremental cost-effectiveness of $824 per quality-adjusted life year, but it is less effective than total hip arthroplasty, on the average, with an incremental effectiveness of -1.4 quality-adjusted life years. Periacetabular osteotomy becomes more cost-effective at a longevity of 5.5 years for Tönnis grade-1 coxarthrosis and 18.25 years for Tönnis grade-2 coxarthrosis. In Tönnis grade-3 coxarthrosis, total hip replacement becomes the dominant treatment strategy.

CONCLUSIONS

Periacetabular osteotomy is, on the average, more cost-effective in Tönnis grade-1 and grade-2 coxarthrosis, while it is both more costly and less effective in Tönnis grade-3 coxarthrosis. These findings can inform clinical decision-making in the absence of long-term data. On the basis of this model, periacetabular osteotomy is preferable to total hip arthroplasty in Tönnis grade-1 and grade-2 coxarthrosis when the patient is sufficiently young and when functionality in sports is important.

The benefit of modified rehabilitation and minimally invasive techniques in total hip replacement

INTRODUCTION

We wished to assess if an intensive rehabilitation regimen alone, or one combined with modified anaesthetic and surgical techniques, can change the speed of rehabilitation or the length of hospital stay after total hip replacement.

PATIENTS AND METHODS

We compared 44 patients who had followed a traditional care pathway, with 38 patients who had rehabilitated under a new rehabilitation protocol, with 40 patients who had also received modified, minimally invasive techniques. The speed of rehabilitation was measured in terms of three specific milestones accomplished on the day after surgery.

RESULTS

We found a statistically significant improvement in the day after surgery each activity was possible. The length of hospital stay was reduced from 6.5 days to 5.4 days to 4.1 days, a difference which was also statistically significant.

CONCLUSIONS

The data support the view that a new rehabilitation protocol alone can reduce the length of hospital stay and hasten rehabilitation. The combination of modified anaesthetic and minimally invasive surgical techniques with the new rehabilitation regimen can further improve short-term outcome after total hip replacement.

``Not Everyone Who Needs One Is Going to Get One'': The Influence of Medical Brokering on Patient Candidacy for Total Joint Arthroplasty

Background. Many patients in Ontario, despite being appropriate candidates for total joint arthroplasty (TJA), are not offered surgery. To understand this discrepancy, the authors sought to explore the process by which physicians determine patient candidacy for TJA. Methods. Six focus groups (2 each of orthopedic surgeons, of rheumatologists, and of family physicians) and subsequent in-depth interviews were conducted with 50 practicing clinicians in Ontario. Results. Health care system constraints, including extensive waiting lists, lack of homecare and postoperative support, and, for surgeons, access to operating rooms and resources, are perceived by physicians to routinely influence the ultimate choice of candidates for TJA. Medical brokering, defined as strategies used by physicians in a constrained health system to prioritize patients and to negotiate relationships with other physicians, was an important factor in determining candidacy for TJA. Because individual physicians and surgeons appear to use their own criteria for making these decisions, and because these criteria are modified from time to time in response to specific institutional and system conditions, brokering results in varied decisions about candidacy regardless of patient suitability. Conclusions. Lack of consensus on the necessary patient characteristics for TJA candidacy does not in and of itself account for the discrepancy between the number of patients who are suitable candidates for TJA and those who receive the procedure. Until the process by which health care system constraints affect and complicate the decision-making process around TJA candidacy is more fully explored, patients may not receive appropriate and timely access to this procedure.

Cost-effectiveness of cemented versus cementless total hip arthroplasty. A Markov decision analysis based on implant cost

BACKGROUND

Probabilistic decision analysis is a means of reflecting the uncertainty parameter in models and of presenting it in a comprehensible manner to decision-makers.

MATERIALS AND METHODS

A cost-effectiveness model was constructed to compare the cementless and cemented total hip prostheses implanted at our department in terms of lifetime costs and quality-adjusted life-years (QALY). Revision rates were obtained from the Orthopaedic Prosthesis Register of the Laboratory of Medical Technology, Istituti Ortopedici Rizzoli, Bologna, Italy.

RESULTS

The risk of early revision (at 5 years of follow-up) for cementless and cemented prostheses was 1.6% and 1.4%, respectively, resulting in equal QALY for the two implant types. Analysis of mean cost and QALY indicated that use of either implant is not associated with cost savings.

DISCUSSION

Management with cementless or cemented total hip prostheses in a theoretical cohort of 70-year-old patients with fracture of the femoral neck or arthritis involving the hip is not significantly different according to the probabilistic results from the model.

Ten-year life expectancy after primary total hip replacement

We determined the ten-year life expectancy of 5831 patients who had undergone 6653 elective primary total hip replacements at a regional orthopaedic centre between April 1993 and October 2004. Using hospital, general practitioner and the local health authority records, we recorded the dates of death for those who died following surgery. The mean age at operation was 67 years (13 to 96) with a male:female ratio of 2:3. Of 1154 patients with a ten-year follow-up 340 (29.5%) had died a mean of 5.6 years (0 to 10) after surgery. Using Kaplan-Meier curves, the ten-year survival was 89% in patients under 65 years at surgery, 75% in patients aged between 65 and 74 years, and 51% in patients over 75. The standardised mortality rates were considerably higher for patients under 45 years, 20% higher for those between 45 and 64 years, and steadily reduced in patients aged 65 and over. The survival of cemented hip replacement derived from the Swedish Hip Arthroplasty Register Annual Report 2004 exceeds the life expectancy of patients over the age of 60 in our area, suggesting that cemented hip replacement is the procedure of choice in this population.

Is American health care uniquely inefficient?

The U.S. health system has been described as the most competitive, heterogeneous, inefficient, fragmented, and advanced system of care in the world. In this paper, we consider two questions: First, is the U.S. healthcare system productively efficient relative to other wealthy countries, in the sense of producing better health for a given bundle of hospital beds, physicians, nurses, and other factor inputs? Second, is the United States allocatively efficient relative to other countries, in the sense of providing highly valued care to consumers? For both questions, the answer is most likely no. Although no country can claim to have eliminated inefficiency, the United States has high administrative costs, fragmented care, and stands out with regard to heterogeneity in treatment because of race, income, and geography. The U.S. healthcare system is also more likely to pay for diagnostic tests, treatments, and other forms of care before effectiveness is established and with little consideration of the value they provide. A number of proposed reforms that are designed to ameliorate shortcomings of the U.S. healthcare system, such as quality improvement initiatives and coverage expansions, are unlikely by themselves to reduce expenditures. Addressing allocative inefficiency is a far more difficult task but central to controlling costs.

Economic considerations in minimally invasive total joint arthroplasty

Minimally invasive techniques for hip and knee arthroplasty have been gaining popularity in recent years. Despite the apparent widespread enthusiasm for these procedures, there is little published evidence demonstrating superior quality of life outcomes directly attributable to the surgical technique. The current debate regarding the value of minimally invasive surgery extends beyond the demonstrated or potential clinical benefits of these procedures. Economic considerations of patients, surgeons, hospitals, and payers are prominent factors in this debate and will continue to influence the adoption of minimally invasive surgical procedures. Developing an understanding of the barriers posed by our healthcare delivery system to minimally invasive surgical procedures and how these barriers impact each of the stakeholders in the healthcare system will foster a rational deployment of these promising new approaches to hip and knee arthroplasty in the future.

OARSI recommendations for the management of hip and knee osteoarthritis, part I: critical appraisal of existing treatment guidelines and systematic review of current research evidence

PURPOSE

As a prelude to developing updated, evidence-based, international consensus recommendations for the management of hip and knee osteoarthritis (OA), the Osteoarthritis Research Society International (OARSI) Treatment Guidelines Committee undertook a critical appraisal of published guidelines and a systematic review (SR) of more recent evidence for relevant therapies.

METHODS

Sixteen experts from four medical disciplines (primary care two, rheumatology 11, orthopaedics one and evidence-based medicine two), two continents and six countries (USA, UK, France, Netherlands, Sweden and Canada) formed the guidelines development team. Three additional experts were invited to take part in the critical appraisal of existing guidelines in languages other than English. MEDLINE, EMBASE, Science Citation Index, CINAHL, AMED, Cochrane Library, seven Guidelines Websites and Google were searched systematically to identify guidelines for the management of hip and/or knee OA. Guidelines which met the inclusion/exclusion criteria were assigned to four groups of four appraisers. The quality of the guidelines was assessed using the AGREE (Appraisal of Guidelines for Research and Evaluation) instrument and standardised percent scores (0-100%) for scope, stakeholder involvement, rigour, clarity, applicability and editorial independence, as well as overall quality, were calculated. Treatment modalities addressed and recommended by the guidelines were summarised. Agreement (%) was estimated and the best level of evidence to support each recommendation was extracted. Evidence for each treatment modality was updated from the date of the last SR in January 2002 to January 2006. The quality of evidence was evaluated using the Oxman and Guyatt, and Jadad scales for SRs and randomised controlled trials (RCTs), respectively. Where possible, effect size (ES), number needed to treat, relative risk (RR) or odds ratio and cost per quality-adjusted life year gained (QALY) were estimated.

RESULTS

Twenty-three of 1462 guidelines or consensus statements retrieved from the literature search met the inclusion/exclusion criteria. Six were predominantly based on expert opinion, five were primarily evidence based and 12 were based on both. Overall quality scores were 28%, 41% and 51% for opinion-based, evidence-based and hybrid guidelines, respectively (P=0.001). Scores for aspects of quality varied from 18% for applicability to 67% for scope. Thirteen guidelines had been developed for specific care settings including five for primary care (e.g., Prodigy Guidance), three for rheumatology (e.g., European League against Rheumatism recommendations), three for physiotherapy (e.g., Dutch clinical practice guidelines for physical therapy) and two for orthopaedics (e.g., National Institutes of Health consensus guidelines), whereas 10 did not specify the target users (e.g., Ontario guidelines for optimal therapy). Whilst 14 guidelines did not separate hip and knee, eight were specific for knee but only one for hip. Fifty-one different treatment modalities were addressed by these guidelines, but only 20 were universally recommended. Evidence to support these modalities ranged from Ia (meta-analysis/SR of RCTs) to IV (expert opinion). The efficacy of some modalities of therapy was confirmed by the results of RCTs published between January 2002 and 2006. These included exercise (strengthening ES 0.32, 95% confidence interval (CI) 0.23, 0.42, aerobic ES 0.52, 95% CI 0.34, 0.70 and water-based ES 0.25, 95% CI 0.02, 0.47) and nonsteroidal anti-inflammatory drugs (NSAIDs) (ES 0.32, 95% CI 0.24, 0.39). Examples of other treatment modalities where recent trials failed to confirm efficacy included ultrasound (ES 0.06, 95% CI -0.39, 0.52), massage (ES 0.10, 95% CI -0.23, 0.43) and heat/ice therapy (ES 0.69, 95% CI -0.07, 1.45). The updated evidence on adverse effects also varied from treatment to treatment. For example, while the evidence for gastrointestinal (GI) toxicity of non-selective NSAIDs (RR=5.36, 95% CI 1.79, 16.10) and for increased risk of myocardial infarction associated with rofecoxib (RR=2.24, 95% CI 1.24, 4.02) were reinforced, evidence for other potential drug related adverse events such as GI toxicity with acetaminophen or myocardial infarction with celecoxib remained inconclusive.

CONCLUSION

Twenty-three guidelines have been developed for the treatment of hip and/or knee OA, based on opinion alone, research evidence or both. Twenty of 51 modalities of therapy are universally recommended by these guidelines. Although this suggests that a core set of recommendations for treatment exists, critical appraisal shows that the overall quality of existing guidelines is sub-optimal, and consensus recommendations are not always supported by the best available evidence. Guidelines of optimal quality are most likely to be achieved by combining research evidence with expert consensus and by paying due attention to issues such as editorial independence, stakeholder involvement and applicability. This review of existing guidelines provides support for the development of new guidelines cognisant of the limitations in existing guidelines. Recommendations should be revised regularly following SR of new research evidence as this becomes available.

Predicting joint replacement waiting times

Currently, the median waiting time for total hip and knee replacement in Ontario is greater than 6 months. Waiting longer than 6 months is not recommended and may result in lower post-operative benefits. We developed a simulation model to estimate the proportion of patients who would receive surgery within the recommended waiting time for surgery over a 10-year period considering a wide range of demand projections and varying the number of available surgeries. Using an estimate that demand will grow by approximately 8.7% each year for 10 years, we determined that increasing available supply by 10% each year was unable to maintain the status quo for 10 years. Reducing waiting times within 10 years required that the annual supply of surgeries increased by 12% or greater. Allocating surgeries across regions in proportion to each region's waiting time resulted in a more efficient distribution of surgeries and a greater reduction in waiting times in the long-term compared to allocation strategies based only on the region's population size.

Arthritis-specific health beliefs related to aging among older male patients with knee and/or hip osteoarthritis

BACKGROUND

Disease-specific beliefs may impact patients' perceptions of the efficacy of various treatment options, thus, it is important to understand these beliefs. We examined the relationship between patients' demographic characteristics and arthritis-specific beliefs related to aging.

METHODS

We performed a cross-sectional survey of 591 elderly primary care patients, who had symptomatic osteoarthritis (OA) of the knee and/or hip, at the Louis Stokes VA Medical Center in Cleveland, Ohio. Data were collected on age, race, educational level, income, and whether patients agreed or disagreed with four statements regarding aging and arthritis. We also assessed OA symptom severity using the Western Ontario McMaster Universities Index (WOMAC) and depressive symptoms using the Geriatric Depression Scale. We used logistic regression analyses to examine relationships between patients' age, race, and educational level and arthritis-specific health beliefs, while adjusting for OA symptom severity, radiographic confirmation of OA, OA joint burden, depressive symptoms, and income.

RESULTS

Patients 70 years old or older, as compared to patients 50-59 years old, were more likely to believe that: arthritis is a natural part of growing old; people should expect that when they get older, they won't be able to walk as well, and people should expect to live with pain as they grow older.

CONCLUSION

Among older, male veterans, health beliefs regarding the relationship between aging and arthritis vary by age. Clinicians should consider these differences when discussing treatment strategies with their patients with knee and/or hip OA.

Shoulder arthroplasty versus hip and knee arthroplasties: a comparison of outcomes

Although outcomes of shoulder, hip, and knee arthroplasties have been well-described, there have been no studies directly comparing the outcomes of these procedures as treatments for osteoarthritis. We compared the inpatient mortality, complications, length of stay, and total charges of patients who had shoulder arthroplasty for osteoarthritis with those of patients who had hip and knee arthroplasties for osteoarthritis. A review of the Maryland Health Services Cost Review Commission discharge database identified 994 shoulder arthroplasties, 15,414 hip arthroplasties, and 34,471 knee arthroplasties performed for osteoarthritis from 1994 to 2001. There were no in-hospital deaths after shoulder arthroplasty, whereas 27 (0.18%) and 54 (0.16%) deaths occurred after hip and knee arthroplasties, respectively. Compared with patients who had hip or knee arthroplasties, patients who had shoulder arthroplasties had, on average, a lower complication rate, a shorter length of stay, and fewer total charges. The latter had 1/2 as many in-hospital complications, were 1/6 as likely to have a length of stay 6 days or greater, and were 1/10 as likely to be charged more than $15,000. We believe shoulder arthroplasty is as safe as the more commonly performed major joint arthroplasties.

A patient-centered perspective on surgery avoidance for hip or knee arthritis: Lessons for the future

OBJECTIVE

Research indicates that there is a discrepancy between need and patient preference for total joint arthroplasty (TJA), an efficacious and cost-effective treatment for severe hip or knee arthritis. To understand this discrepancy, we conducted qualitative research to assess the illness perceptions and preferred accommodations and coping strategies of patients with advanced osteoarthritis who had expressed a preference to avoid TJA.

METHODS

In-depth interviews were conducted with a community sample of 29 men and women who were medically assessed as appropriate candidates for TJA but who had expressed a preference to avoid surgery. Inductive content analysis of text data was used to examine how patients' illness perceptions and preferred coping strategies related to surgery preference.

RESULTS

Participants frequently rejected the medicalization of arthritis, normalizing the experience of functional decline and defining it as age normative. Participants drew on a broad set of previous experiences with informal and formal care to make decisions about how to manage their condition. Previous negative encounters in medical and surgical care, including those from a distant past or those experienced vicariously, combined with the perception (reinforced by physicians and others) that doing nothing was a viable option deterred arthritis-related help seeking in the health care system.

CONCLUSION

Individuals with arthritis may benefit from additional counseling regarding effective medical and surgical treatments. Physicians may better meet patient needs by gauging patient preferences for a combination of self-management strategies and medical interventions.

Factors affecting survival of uncemented total hip arthroplasty in patients 50 years or younger

Providing a long-lasting total hip arthroplasty for patients younger than 50 years remains one of the greatest challenges for modern arthroplasty surgery. We retrospectively reviewed 221 patients younger than 50 years who underwent 299 uncemented total hip arthroplasties from 1983 to 2000. We assessed 5- to 15-year survival with revision as the endpoint. Femoral stem survival was 99.3% (range, 98.4-100%), 98.9% (range, 97.7-100%), and 96.8% (92.5-100%) at 5, 10, and 15 years, respectively. Including all component designs acetabular survival was 98.7% (range, 97.4-100%), 84.6% (78.8-90.4%), and 52.5% (40.7-64.3%) at 5, 10, and 15 years, respectively. Overall survival was 46.8% (33.5-58.1%) at 15 years. Total hip arthroplasties performed for hip dysplasia had lower 10-year and 15-year survival. Zirconium-on-polyethylene articulations had lower acetabular revision rates compared with cobalt-chrome-on-polyethylene. Sixty-nine revisions were performed, most commonly for polyethylene wear. Uncemented femoral stems resulted in 90% survival at 15 years followup in patients younger than 50 years at index operation. Contemporary bearing surfaces in association with such stems may provide long-lasting total hip arthroplasties, even in young, active patients.

[The cemented MS-30 stem. A multi-surgeon series of 333 consecutive cases]

INTRODUCTION

So far there is only one peer-reviewed long-term publication from the inventors' clinic for the MS-30 stem.

MATERIAL AND METHODS

In a retrospective study we followed the first 333 consecutive MS-30 stems. All patients with 5- to 11-year follow-up were clinically and radiographically evaluated. At the time of implantation the criteria of modern cementing techniques were not implemented. Clinical evaluation was done using the scores of Harris and Merle d'Aubigné and Postel. Radiographic evaluation included quality of the cement mantle (true lateral radiographs taken under fluoroscopy), stem subsidence, loosening signs, and the risk for pending failure.

RESULTS

At follow-up 12 hips had undergone femoral revision: 3 for aseptic loosening, 6 for infection, 1 for periprosthetic fracture, and 2 for recurrent dislocation. The overall survival for all reasons at 10 years was 96.1%; survival with aseptic loosening as an end point was 99.0%. The median Harris Hip Score at follow-up was 80 (26-100) points. Radiological evaluation revealed a thin cement mantle (<2 mm) in approximately 2/3, predominantly on the lateral views (Gruen zones 8/9). One-third of all reviewed prostheses were considered at risk for pending failure, which strongly correlated with the initial quality of the cement mantle.

CONCLUSION

Midterm results with the MS-30 stem are encouraging and an even better long-term outcome can be expected with a better cement technique.

A prospective population-based study of the predictors of undergoing total joint arthroplasty

OBJECTIVE

To examine prospectively the predictors of time to total joint arthroplasty (TJA).

METHODS

This was a prospective cohort study with a median followup time of 6.1 years. We included participants from an existing population-based cohort of 2,128 individuals, ages 55 years and older with disabling hip and/or knee arthritis and no prior TJA, from 2 regions of Ontario, Canada, 1 urban with low TJA rates and 1 rural with high rates. The main outcome measure was the occurrence of a TJA based on procedure codes in the hospital discharge abstract database.

RESULTS

At baseline, the mean age of the patients was 71.5 years, 67.9% had a high school education or higher, 73.4% were women, the mean arthritis severity (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]) score was 41.1 (maximum possible score 100), and 20.0% were willing to consider TJA. Greater probability of undergoing TJA was associated with higher (worse) baseline WOMAC scores (hazard ratio [HR] 1.22 per 10-unit increase, P < 0.001), age (compared with age <or=62 years, the HR increased to 1.57 for 63-68 years, 1.46 for 69-74 years, and 1.51 for 75-81 years, and fell to 0.44 for >or=82 years; P < 0.05 for all), better health (HR 1.14 per 10-unit increase in Short Form 36 general health survey score, P < 0.001), and willingness to consider TJA (HR 4.92, P < 0.001). When willingness was excluded from the model, education level, but not sex or income, became a significant predictor of TJA receipt.

CONCLUSION

Willingness to consider TJA was the strongest predictor of the time to first TJA. Given that previous research indicates that willingness is largely explained by perceptions of the indications for and risks associated with TJA and not disease severity, this finding supports the need for population education about arthritis treatments, including TJA.

Patients' outcome after total hip arthroplasty: a comparison between the Western Ontario and McMaster Universities index and the Oxford 12-item hip score

This prospective cohort study included 402 patients who had primary total hip arthroplasty. The Western Ontario and McMaster Universities Index (WOMAC) and the Oxford 12-item Hip Score (OHS) were used to assess patients preoperatively and at 1 year postoperation. The OHS has a higher responsiveness than the WOMAC in the global scale and in the pain subscale. However, the WOMAC has better responsiveness in its function scale. The point estimate of relative precision of measuring postoperative quality of life shows that the OHS has a tendency toward a better performance than the WOMAC; however, this finding is not statistically significant. The OHS also demonstrates similar floor and ceiling effect patterns as does the WOMAC. We recommend that the choice should depend on which scale researchers are using to power a study.

Cost-effectiveness analysis of core decompression

Core decompression is widely used to treat the early stages of osteonecrosis of the hip. The purpose of this analysis is to assist orthopedic surgeons in judging whether currently available data support the use of core decompression as cost-effective. A decision model was created for the treatment of osteonecrosis of the femoral head. Literature review was used to identify possible outcomes and their probability after initial treatment with either observation or core decompression. This model demonstrates core decompression must delay the need for total hip arthroplasty for a minimum of 5 years to maintain an incremental cost-effectiveness ratio lower than 50,000 dollars per quality-adjusted life year gained. Treatment options with ratios higher than 50,000 dollars per quality-adjusted life year are generally considered to have limited cost-effectiveness. This study demonstrates that core decompression has the potential to be a highly cost-effective alternative if it is leads to a delay in the need for total hip arthroplasty of 5 years or longer.

Current issues in joint replacement surgery

PURPOSE OF REVIEW

Joint replacement surgery continues to grow in sheer number of procedures and quantity of research. We wish to highlight the key findings in the literature about variations in utilization, timing of procedure, outcomes, and minimally invasive techniques.

RECENT FINDINGS

Several studies reinforce the improved pain and function after joint replacement surgery. The best predictor of postoperative pain and function appears to be preoperative pain and function, respectively. In one study, authors expressed concern that patients may be systematically reporting better outcomes than they truly achieve. In spite of the generally favorable results after surgery, there remains considerable geographic, racial, and gender variation in utilization. The optimal timing for surgery is unknown but may be influenced by the advent of the newer longer-lasting prosthesis. Patients with poorer preoperative function tend to have poorer outcomes, regardless of baseline pain or function. Evidence thus far has demonstrated similar outcomes between minimal and standard incisions for hip arthroplasty.

SUMMARY

Advances in our understanding of outcomes after joint replacement aid in predicting best candidates for surgery. More study is needed on the optimal timing of replacement surgery and the variations in utilization.

Recurrent instability after total hip arthroplasty: beware of subtle component malpositioning

Most patients exhibiting instability after total hip arthroplasty can be treated nonoperatively. However, instability may become recurrent and require surgical intervention. Abductor insufficiency and component malpositioning constitute two of the most important causes of recurrent instability, although the exact cause may not be identifiable in some patients. There is relative scarcity of reports in the literature regarding the outcome of surgical intervention for recurrent instability; however, it is known that surgical intervention is likely to have a better outcome in patients for whom the cause of recurrent instability can be identified. We hypothesized that component malpositioning, which may be subtle in some cases, is the cause of recurrent instability for many patients. The outcomes of revision arthroplasty in 93 patients who were treated at our institution for recurrent instability were reviewed. Component malpositioning was found to be the major cause of recurrent instability in this successfully treated cohort.

Antero-lateral minimal invasive (ALMI) approach for total hip arthroplasty technique and early results

INTRODUCTION

Minimally invasive surgery represents one of the most recent techniques to have emerged within THA. In conventional THA, the incision typically measures 15-20 cm. Minimal invasive approach defined as less invasive to the skin, muscles, or bone may reduce complications and improve recovery time. A number of different approaches and methods have been described in literature.

PURPOSE

This is a prospective study describing the technique and early results of the modified antero-lateral minimal invasive (ALMI) approach and comparing our results to the results of other investigators interested in minimal invasive THA.

MATERIALS AND METHODS

Seventy-five consecutive primary total hip arthroplasties (cemented and cementless) were done through a modified ALMI approach (6-8 cm), in which we kept the hip abductors intact. Neither special instruments nor specially designed prostheses were needed. Minimum follow-up was 12 months.

RESULTS

The mean Harris hip score for patients after 12-month follow-up was 90 while the mean Merle d'Abugine mean score was 16.5. Both scores reached almost the maximum values within 3 months after surgery. The cup abduction angle for 70% patients was between 35 degrees and 45 degrees. No femoral stem mal-alignment was recorded. The mean operative time of cemented prosthesis was 65 min while that of the cementless prosthesis was 55 min. No wound complications or dislocations were recorded. All the patients were allowed to weight bear in the second post-operative day and involved in an early rehabilitation program.

CONCLUSION

ALMI hip approach with sparing of hip abductors is safe and gives excellent orientation for positioning of prosthesis components. It also allows early and smooth post-operative rehabilitation with fast recovery of the patient in terms of weight bearing.

Willingness to pay for a quality-adjusted life year: implications for societal health care resource allocation

BACKGROUND

Health-state preferences can be combined with willingness-to-pay (WTP) data to calculate WTP per quality-adjusted life year (QALY). The WTP/QALY ratios provide insight into societal valuations of expenditures for medical interventions.

METHODS

The authors measured preferences for current health in 3 patient populations (N = 391) using standard gamble, time trade-off, visual analog scale, and WTP, then they calculated WTP/QALY ratios. The ratios were compared with several proposed cost/QALY cost-effectiveness ratio thresholds, the value-of-life literature, and with WTP/QALY ratios derived from published preference research.

RESULTS

Mean WTP/QALY ratios ranged from 12,500 to 32,200 US dollars (2003 US dollars). All values were below most published cost-effectiveness ratio thresholds, below the ratio from a prototypic medical treatment covered by Medicare (i.e., renal dialysis), and below ratios from the value-of-life literature. The WTP/QALY ratios were similar to those calculated from published preference data for patients with symptomatic meno-pause, dentofacial deformities, asthma, or dermatologic disorders.

CONCLUSIONS

WTP/QALY ratios calculated using preference data collected from diverse populations are lower than most proposed thresholds for determining what is "cost-effective." Current proposed cost-effectiveness ratio thresholds may overestimate the willingness of society to pay for medical interventions.

Hospital cost of dislocation after primary total hip arthroplasty

BACKGROUND

The treatment of dislocation following primary total hip arthroplasty usually requires the use of expensive hospital resources and sometimes requires revision surgery. The hospital costs associated with treating this complication have not been previously analyzed, to our knowledge. The purpose of this study was to assess the financial impact of treating dislocations at our institution.

METHODS

Between 1997 and 2001, 3671 patients underwent a total of 4054 consecutive primary total hip arthroplasties at our institution. The patients were prospectively followed at regular intervals, and their follow-up data were recorded in an institutional total joint registry. Ninety-nine hips (2.4%) in ninety-nine patients dislocated. The costs to our institution to treat these dislocations were evaluated by determining the cost of each treatment episode required to reestablish hip stability and were expressed as the percent increase in cost compared with that of an uncomplicated primary total hip replacement.

RESULTS

Of the ninety-nine hips that dislocated, sixty-two (63%) remained stable after one or more closed reductions and thirty-seven (37%) ultimately required revision surgery. The hospital cost of each closed reduction episode represented 19% of the hospital cost of an uncomplicated total hip replacement. When revision surgery was eventually needed, the average hospital costs of one or more closed reductions and the subsequent revisions represented 148% of the hospital cost of an uncomplicated primary total hip replacement.

CONCLUSIONS

Dislocation after primary hip replacement continues to be a prevalent and costly complication that diminishes the cost-effectiveness of an otherwise very successful surgical procedure.

Cost-benefit analysis of MIS THA: Model-based analysis of the consequences for Switzerland

The objective of this study was to show model-based economic consequences of minimal invasive surgery total hip arthroplasty (MIS THA). The model is based on hospital and rehabilitation costs and lowering of loss of productivity. This study used conventional THA data from Switzerland and cost-effectiveness MIS THA analysis from the United States. According to our model, a total of 42.1 70.1 million can be saved annually in Switzerland when using MIS THA instead of conventional THA. Annual savings of 7,8 12,9 million result from the significantly shorter hospital stay. The savings potential for rehabilitation costs is 10,5 17,5 million annually. In addition, the productivity loss for the economy is lowered by 23.8 39.7 million annually. According to this economic study we recommend the introduction of MIS techniques in THA. MIS THA surgical techniques may allow the reduction of healthcare costs. Despite the promising economic advantages of MIS THA, clinical studies are necessary to prove long-term benefits.

Waiting for hip arthroplasty: economic costs and health outcomes

This prospective cohort study of 153 patients aimed to determine the economic and health costs of waiting for total hip arthroplasty (THA). Health-related quality of life, using self-completed WOMAC and EQ-5D questionnaires, was assessed monthly from enrolment preoperatively to 6 months postsurgery. Monthly cost diaries were used to record costs. The mean waiting time was 5.1 months and mean total cost of waiting for surgery was NZ 4305 dollars(US 2876 dollars) per person (pp) (NZ 1 dollar = US 0.668 dollar). Waiting more than 6 months was associated with a higher total mean cost (NZ 4278 dollars/US 2858 dollars pp) than waiting less than 6 months (NZ 2828 dollars/US 1889 dollars pp; P < .01). Improvements from preoperative to postoperative WOMAC and EQ-5D scores were identified (P < or = .01). Waiting longer led to poorer physical function preoperatively (P < or = .01). Those with poor initial health status showed greater improvement in WOMAC (P = .0001) and EQ-5D (P = .003) measures by 6 months after surgery. Longer waits for total hip arthroplasty incur greater economic costs and deterioration in physical function while waiting.

Outcome of hip arthroplasty in octogenarians compared with younger patients

This prospective study aimed to ascertain if octogenarians undergoing primary hip arthroplasty experienced a similar clinical outcome and complication rate as younger patients. Significantly better (p=0.019) improvement in mean Harris hip score (SD) was seen 18 months after surgery in the younger cohort: 43.4 (SD 13.8) compared with 39.8 (SD 10.6). Length of hospital stay was longer (p<0.001) in the octogenarians: 12.9 days (SD 7.0) days versus 10.1 (SD 4.7) with a higher blood transfusion rate of 40% compared with 28% (p = 0.009). No significant differences in infection, dislocation, thromboembolism or 90-day mortality rates were found.

CONCLUSIONS

octogenarians are more likely to require blood transfusions and a longer hospital stay, with less improvement in clinical outcome at 18 months after primary hip arthroplasty. (Hip International 2005; 15: 206-11).

Racial/ethnic differences in surgical outcomes in veterans following knee or hip arthroplasty

OBJECTIVE

The utilization of joint arthroplasty for knee or hip osteoarthritis varies markedly by patient race/ethnicity. Because of concerns about surgical risk, black patients are less willing to consider this treatment. There are few published race/ethnicity-specific data on joint arthroplasty outcomes. The present study was undertaken to examine racial/ethnic differences in mortality and morbidity following elective knee or hip arthroplasty.

METHODS

Using information from the Veterans Administration National Surgical Quality Improvement Program database, data on 12,108 patients who underwent knee arthroplasty and 6,703 patients who underwent hip arthroplasty over a 5-year period were analyzed. Racial/ethnic differences were determined using prospectively collected data on patient characteristics, procedures, and short-term outcomes. The main outcome measures were risk-adjusted 30-day mortality and complication rates.

RESULTS

Adjusted rates of both non-infection-related and infection-related complications after knee arthroplasty were higher among black patients compared with white patients (relative risk [RR] 1.50, 95% confidence interval [95% CI] 1.08-2.10 and RR 1.42, 95% CI 1.06-1.90, respectively). Hispanic patients had a significantly higher risk of infection-related complications after knee arthroplasty (RR 1.64, 95% CI 1.08-2.49) relative to otherwise similar white patients. Race/ethnicity was not significantly associated with the risk of non-infection-related complications (RR 0.97, 95% CI 0.68-1.38 in blacks; RR 1.18, 95% CI 0.60-2.30 in Hispanics) or infection-related complications (RR 1.27, 95% CI 0.91-1.78 in blacks; RR 1.22, 95% CI 0.63-2.36 in Hispanics) after hip arthroplasty. The overall 30-day mortality was 0.6% following knee arthroplasty and 0.7% following hip arthroplasty, with no significant differences by race/ethnicity observed for either procedure.

CONCLUSION

Although absolute risks of complication are low, our findings indicate that, after adjustment, black patients have significantly higher rates of infection-related and non-infection-related complications following knee arthroplasty, compared with white patients. In addition, adjusted rates of infection-related complications after knee arthroplasty are higher in Hispanic patients than in white patients. Such differences between ethnic groups are not seen following hip arthroplasty. These groups do not appear to differ significantly in terms of post-arthroplasty mortality rates.

Cost effectiveness of a two-year home exercise program for the treatment of knee pain

OBJECTIVE

To assess the cost effectiveness of a 2-year home exercise program for the treatment of knee pain.

METHODS

A total of 759 adults aged > or = 45 years were randomized to receive exercise therapy, monthly telephone contact, exercise therapy and telephone contact, or no intervention. Efficacy was measured using self-reported knee pain at 2 years. Costs to both the National Health Service and to the patient were included.

RESULTS

Exercise therapy was associated with higher costs and better effectiveness. Direct costs for the interventions were pound 112 for the exercise program and pound 61 for the monthly telephone support. Participants allocated to receive exercise therapy were significantly more likely to incur higher medical costs than those in the no-exercise groups (mean difference pound 225; 95% confidence interval pound 218, pound 232; P < 0.001).

CONCLUSION

Exercise therapy is associated with improvements in knee pain, but the cost of delivering the exercise program is unlikely to be offset by any reduction in medical resource use.