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

Determining who should be referred for total hip and knee replacements

Total hip and total knee replacements (THR and TKR respectively), the definitive treatments for end-stage arthritis, are both safe and extremely successful in relieving pain and improving function. However, physicians who care for patients with chronic hip and knee arthritis are often the 'gatekeepers' to total joint replacement (TJR) procedures as they select patients for referral to an orthopaedic surgeon to be considered for arthroplasty. Currently, no evidence-based criteria exist to guide physicians in this decision-making process, and this situation raises the possibility that conscious or unconscious biases may influence referral patterns, potentially leading to systematic inequities regarding which patients are eventually offered TJR. This article reviews why TJRs are particularly important procedures, and highlights common misperceptions among physicians regarding TJR risk assessment. This article also underscores the benefits of ongoing discussion regarding TJR with all patients with moderate-to-severe chronic hip or knee pain and disability.

Cost-effectiveness analysis of early versus late total hip replacement in Italy

OBJECTIVE

To assess the cost-effectiveness of early primary total hip replacement (THR) for functionally independent older adult patients with osteoarthritis (OA) versus 1) nonsurgical therapy followed by THR once the patient has progressed to a functionally dependent state ("delayed THR") and 2) nonsurgical therapy alone ('medical therapy'), from the Italian National Health Service perspective.

METHODS

Individual patient data and evidence from published literature on disease progression, economic costs and THR outcomes in OA, including utilities, perioperative mortality rates, prosthesis survival, and costs of prostheses, THR, rehabilitation, follow-up, revision, and nonsurgical management, combined with population life tables, were synthesized in a Markov model of OA. The model represents the lifetime experience of a patient cohort following their treatment choice, discounting costs and benefits (quality-adjusted life-years) at 3% annually.

RESULTS

At age 65 years, the incremental cost per quality-adjusted life-year of THR over delayed THR was €987 in men and €466 in women; the figures for delayed THR versus medical therapy were €463 and €82, respectively. Among 80-year-olds, early THR is (extended) dominant. With gradual utility loss after primary THR, delaying surgery may be more appealing in women than in men in their 50s, because longer female life expectancy implies longer latter periods of low health-related quality of life (HRQOL) with early THR.

CONCLUSIONS

THR is cost-effective. Patients' HRQOL benefits forgone with delayed THR are worth more than the costs it saves to the Italian National Health Service. This analysis might help to explain women's consistently lower HRQOL by the time of primary operation.

Outcomes of total hip arthroplasty in the octogenarian population

BACKGROUND

The outcomes of total hip arthroplasty (THA) in the elderly population are uncertain. With the rapid expansion of this population group, this study aims to determine whether increasing age affects the outcomes of THA by utilising the largest patient cohort and follow-up period within the literature.

PATIENTS AND METHODS

All patients of 80 years and over who underwent primary THA between 1994 and 2004 at the authors' institution were compared to a cohort aged under 80 with the same diagnoses and during the same time period. Mean follow-up time was 5.9 years with a select group being reviewed at year 10.

RESULTS

Pain scores were comparable at year five, whilst mean Harris hip scores were significantly lower in the octogenarians. Median hospital stay was three days longer in the elderly group. Complication rates were also higher (38.1% cf 28.7%) however fewer cases of revision were noted (1.4% cf 3.8%). Patient satisfaction was comparable between groups.

CONCLUSION

This study suggests pain improvement, low revision rates and high satisfaction are sufficient to justify THA in the elderly population.

Assessing the value of a total joint replacement

Total joint arthroplasty (TJA) continues to be one of the most successful surgical interventions in medicine. Demand is growing rapidly, placing an increasingly heavy cost burden on national health systems. Despite the popularity of these surgeries, high-quality cost-effectiveness studies evaluating TJA are few in number. This article summarizes the current literature on value in arthroplasty, identifying the various factors affecting costs and outcomes, and suggesting how policy makers can influence utilization of TJA to further improve value to society.

Is surgical fixation for stress-positive unstable ankle fractures cost effective? Results of a multicenter randomized control trial

OBJECTIVES

A recent multicenter randomized control trial demonstrated similar quality of life at 1 year after open reduction and internal fixation (ORIF) compared with nonoperative treatment for stress-positive unstable isolated lateral malleolar fractures. We sought to determine the cost-effectiveness of ORIF compared with nonoperative management of these isolated lateral malleolar fractures.

DESIGN

Cost-utility analysis using decision tree and Markov modeling based on data from a prospective randomized control trial and previously published literature. A single-payer perspective with 1-year and lifetime time horizons was adopted.

SETTING

Clinical trial data from 6 Canadian level I trauma hospitals.

INTERVENTION

Lateral malleolus ORIF versus nonoperative treatment.

MAIN OUTCOME MEASUREMENTS

Incremental cost-effectiveness ratio (ICER).

RESULTS

The base case 1-year ICER of the ORIF treatment was $205,090 per quality-adjusted life year gained, favoring nonoperative treatment. For the lifetime time horizon, ORIF becomes the preferred treatment with an ICER of $16,404 per quality-adjusted life year gained. This conclusion is stable provided ORIF lowers the lifetime incidence of ankle arthrosis by >3% compared with nonoperative treatment. Probabilistic sensitivity analysis demonstrated that 33% of model simulations favored ORIF in the 1-year time horizon and 65% of simulations in the lifetime time horizon.

CONCLUSIONS

From a single-payer governmental perspective, ORIF does not seem to be cost effective in the 1-year time horizon; however, if operative fixation decreases the lifetime incidence of posttraumatic ankle arthrosis by >3%, then ORIF becomes the economically preferred treatment.

LEVEL OF EVIDENCE

Economic Level II. See Instructions for Authors for a complete description of levels of evidence.

Perioperative complications following total joint replacement

Total joint arthroplasty is a safe and highly effective treatment for moderate to severe osteoarthritic symptoms and other causes of joint derangement in the elderly population. Significant improvements in pain, function, and quality of life are nearly universal, with a low rate of complications and adverse outcomes. Because of its success and cost-effectiveness, the rate of utilization of TJR is increasing, and all health care providers must be familiar with the potential complications and perioperative management of these patients. Elderly patients may be at a higher risk for postoperative medical complications; however, the majority of these complications are minor and many are avoidable with appropriate preoperative screening and careful postoperative management. As with all patients undergoing TJR, patients should be prophylactically treated for infection and thromboembolism and carefully followed for the development of these potential complications as well as fracture, hip dislocation, and neurovascular dysfunction. Postoperative delirium may be minimized and prophylactically treated in appropriate elderly patients to maximize recovery and promote safety.

Acute delirium and poor compliance in total hip arthroplasty patients with substance abuse disorders

From the joint registry of 2831 primary total hip arthroplasties (2351 patients) performed between 1998 and 2003, we identified 15 patients (16 hips) who had a documented history of substance abuse disorders at the time of the index surgery. The patients included 13 men (14 hips) and 2 women (2 hips), with the mean age of 49 years (range, 29-65 years). On the basis of the criteria specified in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, 13 patients had alcohol abuse disorders, 1 had amphetamine abuse disorder, and 1 had heroin abuse disorder. We found high rates of postoperative substance withdrawal delirium and psychosis (46%), late complication (25%), and lost to follow-up (27%) in these patients. Because patients with substance abuse disorders have unexpected perioperative psychotic episodes, poor compliance, and a tendency to not follow medical advice after surgery and show early discontinuation of follow-up, we suggest that surgeons should work with other medical professionals and carefully perform total hip arthroplasty in such patients.

Osteoarthritis patients' perceptions of "appropriateness" for total joint replacement surgery

OBJECTIVE

To understand patients' perspectives on 'appropriateness' for hip and knee total joint arthroplasty (TJA).

METHODS

Focus groups were conducted, stratified by history of a previous TJA, in English-speaking men and women aged 40+ years with moderate to severe hip and knee osteoarthritis. Participants discussed: their appropriateness for TJA; the ideal candidate; patients' role in TJA decision making; and the relationship between appropriateness and willingness to consider TJA. Participants self-completed a questionnaire assessing demographics, arthritis severity (Western Ontario McMaster University Osteoarthritis index - WOMAC), perceived TJA candidacy and willingness to consider TJA. Focus groups were audio-taped and transcribed verbatim. Content analysis was performed.

RESULTS

Eleven focus groups were conducted with 58 participants in total: mean age 72 years; 79% female; 25 (43%) with prior TJA; mean WOMAC summary score 43.1. Half reported willingness to consider TJA and 43% felt they were appropriate for TJA. Appropriateness was equated with candidacy for the procedure. Pain intensity and the ability to cope with pain were identified as the most important factors determining surgical candidacy, but felt to be inadequately evaluated by physicians. TJA appropriateness and willingness were felt to be distinct, yet related, concepts; those unwilling had stricter criteria about candidacy than those who were willing.

CONCLUSIONS

Participants equated appropriateness for TJA with surgical candidacy. Patients' pain experience (intensity, impact on quality of life, ability to cope) was seen as most important in determining appropriateness, but felt to be inadequately evaluated currently. Enhanced patient-physician communication, possibly through use of patient decision aids, has potential to improve patient selection for TJA.

Understanding recovery: changes in the relationships of the International Classification of Functioning (ICF) components over time

The International Classification of Functioning, Disability and Health framework describes human functioning through body structure and function, activity and participation in the context of a person's social and physical environment. This work tested the temporal relationships of these components. Our hypotheses were: 1) there would be associations among physical impairment, activity limitations and participation restrictions within time; 2) prior status of a component would be associated with future status; 3) prior status of one component would influence status of a second component (e.g. prior activity limitations would be associated with current participation restrictions); and, 4) the magnitude of the within time relationships of the components would vary over time. Participants from Canada with primary hip or knee joint replacement (n = 931), an intervention with predictable improvement in pain and disability, completed standardized outcome measures pre-surgery and five times in the first year post-surgery. These included physical impairment (pain), activity limitations and participation restrictions. ICF component relationships were evaluated cross-sectionally and longitudinally using path analysis adjusting for age, sex, BMI, hip vs. knee, low back pain and mood. All component scores improved significantly over time. The path coefficients supported the hypotheses in that both within and across time, physical impairment was associated with activity limitation and activity limitation was associated with participation restriction; prior status and change in a component were associated with current status in another component; and, the magnitude of the path coefficients varied over time with stronger associations among components to three months post surgery than later in recovery with the exception of the association between impairment and participation restrictions which was of similar magnitude at all times. This work enhances understanding of the complexities of the ICF component relationships in evaluating disability over time. Further longitudinal studies including evaluation of contextual factors are required.

A financial analysis of revision hip arthroplasty: the economic burden in relation to the national tariff

Revision arthroplasty of the hip is expensive owing to the increased cost of pre-operative investigations, surgical implants and instrumentation, protracted hospital stay and drugs. We compared the costs of performing this surgery for aseptic loosening, dislocation, deep infection and peri-prosthetic fracture. Clinical, demographic and economic data were obtained for 305 consecutive revision total hip replacements in 286 patients performed at a tertiary referral centre between 1999 and 2008. The mean total costs for revision surgery in aseptic cases (n = 194) were £11 897 (sd 4629), for septic revision (n = 76) £21 937 (sd 10 965), for peri-prosthetic fracture (n = 24) £18 185 (sd 9124), and for dislocation (n = 11) £10 893 (sd 5476). Surgery for deep infection and peri-prosthetic fracture was associated with longer operating times, increased blood loss and an increase in complications compared to revisions for aseptic loosening. Total inpatient stay was also significantly longer on average (p < 0.001). Financial costs vary significantly by indication, which is not reflected in current National Health Service tariffs.

Hospital cost of treating early dislocation following hip arthroplasty

Dislocation is a frequent and costly complication of hip arthroplasty. The purpose of this study was to assess the financial impact on the treating institution of this complication in patients with primary hemiarthroplasty (HA), total hip arthroplasty (THA) and revision surgery (RTHA). Between October 2001 and August 2009, 2014 consecutive hip arthroplasties were performed at our institution, of which 87 (18 HA, 44 THA and 25 RTHA) dislocated within 6 weeks of the primary operation. The average cost of treating implant dislocation by closed reduction, open reduction or revision was assessed and expressed as a percentage cost increase compared to an uncomplicated procedure. Of the 87 dislocated implants all needed one or more closed reductions and 52 eventually required revision surgery. An early dislocation increased the cost of HA, THA and RTHA by 472%, 342% and 352%, respectively.

Reducing the rate of early primary hip dislocation by combining a change in surgical technique and an increase in femoral head diameter to 36 mm

INTRODUCTION

We report how changes to our total hip arthroplasty (THA) surgical practise lead to a decrease in early hip dislocation rates.

METHODS

Group B consisted of 421 consecutive primary THA operations performed via a posterior approach. The operative technique included a meticulous repair of the posterior capsule, alignment of the acetabular cup with the transverse acetabular ligament (TAL) and a 36-mm-diameter femoral head. We compared the dislocation rates and cost implications of this technique to a historical control Group A consisting of 389 patients. The control group had their THA performed with no repair of the capsule, no identification of the TAL and all received a 28-mm-diameter head. Our primary outcome is the rate of early hip dislocation and we hypothesised that we can reduce the rate of early hip dislocation with this new regime.

RESULTS

In Group B there were no early dislocations (within 6 months) and two (0.5 %) dislocations within 18 months; minimum follow-up time was 18 months with a range of (18-96 months). This compared to a 1.8 % early dislocation rate and a 2.6 % rate at 18 months in Group A; minimum follow-up time was 60 months with a range of (60-112 months). These results were statistically significant (p = 0.006).

CONCLUSION

We suggest that when primary hip arthroplasty is performed through a posterior approach, a low early dislocation rate can be achieved using the described methods.

Comparative effectiveness research in spine surgery

Comparative effectiveness research (CER) has impending significance for the field of spine surgery. This article outlines the rationale for comparative effectiveness research and reviews recommended priorities of spinal surgery emphasis. It also examines recent key studies of CER in the spine surgery literature and associated cost-effectiveness studies. It concludes with a discussion of the direction of CER in the spine surgery community.

Cost-effectiveness analysis of autologous chondrocyte implantation: a comparison of periosteal patch versus type I/III collagen membrane

BACKGROUND

Autologous chondrocyte implantation (ACI) involves the use of a periosteal patch (ACI-P) as a cover for transplanted chondrocytes. Theoretically, this periosteal patch provides mesenchymal stem cells and growth factors that encourage chondrocyte development/differentiation. However, there is a significant rate of graft hypertrophy with the use of periosteum compared with using a type I/III collagen patch (ACI-C). This type I/III collagen patch, although not approved by the United States Food and Drug Administration for ACI, has been used extensively in Europe and in an "off-label" nature in the United States as a cover during ACI.

PURPOSE

To examine the cost effectiveness of ACI and determine whether ACI-C is more cost effective than ACI-P.

STUDY DESIGN

Economic and decision analysis; Level of evidence, 2.

METHODS

Outcome data and complication rates from patients undergoing ACI (ACI-P and ACI-C) were derived from the best evidence in the literature. Costs were determined by examining the typical patient charges undergoing ACI at a local orthopaedic hospital. The costs, results, and complication rates were used to develop a decision analysis model comparing ACI-P to ACI-C.

RESULTS

The cost of ACI-P was $66,752 and for ACI-C was $66,939.50 ($187.50 difference). The cost per quality-adjusted life year (QALY) for ACI-P was $9466 compared with $9243 for ACI-C. Sensitivity analysis was performed regarding the additional cost of the type I/III collagen patch ($780) in ACI-C as well as the rate of graft hypertrophy after ACI-P (25%). This analysis revealed that the cost of the type I/III collagen patch would have to reach $1721, or the rate of graft hypertrophy after ACI-P reduced to almost 11%, before ACI-P became more cost effective than ACI-C.

CONCLUSION

This cost-effectiveness analysis reveals that, while both ACI-P and ACI-C are cost effective, ACI-C is slightly more cost effective than ACI-P. This is likely secondary to the significant rate of patch-related complications associated with ACI-P, which is significantly reduced with ACI-C. Although the model is very sensitive to differences in outcomes between ACI-P and ACI-C, there is no high-quality evidence to suggest that there is a significant difference between the two. Thus, ACI-P becomes more cost effective if the cost of the type I/III collagen membrane is significantly increased or if the rate of graft hypertrophy after ACI-P were to be markedly reduced.

Cross-sectional analysis of association between socioeconomic status and utilization of primary total hip joint replacements 2006-7: Australian Orthopaedic Association National Joint Replacement Registry

BACKGROUND

The utilization of total hip replacement (THR) surgery is rapidly increasing, however few data examine whether these procedures are associated with socioeconomic status (SES) within Australia. This study examined primary THR across SES for both genders for the Barwon Statistical Division (BSD) of Victoria, Australia.

METHODS

Using the Australian Orthopaedic Association National Joint Replacement Registry data for 2006-7, primary THR with a diagnosis of osteoarthritis (OA) among residents of the BSD was ascertained. The Index of Relative Socioeconomic Disadvantage was used to measure SES; determined by matching residential addresses with Australian Bureau of Statistics census data. The data were categorised into quintiles; quintile 1 indicating the most disadvantaged. Age- and sex-specific rates of primary THR per 1,000 person years were reported for 10-year age bands using the total population at risk.

RESULTS

Females accounted for 46.9% of the 642 primary THR performed during 2006-7. THR utilization per 1,000 person years was 1.9 for males and 1.5 for females. The highest utilization of primary THR was observed in those aged 70-79 years (males 6.1, and females 5.4 per 1,000 person years). Overall, the U-shaped pattern of THR across SES gave the appearance of bimodality for both males and females, whereby rates were greater for both the most disadvantaged and least disadvantaged groups.

CONCLUSIONS

Further work on a larger scale is required to determine whether relationships between SES and THR utilization for the diagnosis of OA is attributable to lifestyle factors related to SES, or alternatively reflects geographic and health system biases. Identifying contributing factors associated with SES may enhance resource planning and enable more effective and focussed preventive strategies for hip OA.

Mapping the Oxford hip score onto the EQ-5D utility index

PURPOSE

To assess different mapping methods for the estimation of a group's mean EQ-5D score based on responses to the Oxford hip score (OHS) questionnaire.

METHODS

Four models were considered: a) linear regression using total OHS as a continuous regressor; b) linear regression employing responses to the twelve OHS questions as categorical predictors; c) two-part approach combining logistic and linear regression; and d) response mapping. The models were internally validated on the estimation data set, which included OHS and EQ-5D scores for total hip replacements, both before and six months after procedure for 1,759 operations. An external validation was also performed.

RESULTS

All models estimated the mean EQ-5D score within 0.005 of an observed health-state utility estimate, ordinary least squares (OLS) continuous being the most accurate and OLS categorical the most consistent. Age, gender and deprivation did not improve the models. More accurate estimations at the individual level were achieved for higher scores of observed OHS and EQ-5D.

CONCLUSION

Based on these results, when EQ-5D scores are not available, answers to the OHS questionnaire can be used to estimate a group's mean EQ-5D with a high degree of accuracy.

Cost-utility analysis of primary prophylaxis versus secondary prophylaxis with granulocyte colony-stimulating factor in elderly patients with diffuse aggressive lymphoma receiving curative-intent chemotherapy

PURPOSE

The 2006 American Society of Clinical Oncology (ASCO) guideline recommended primary prophylaxis (PP) with granulocyte colony-stimulating factor (G-CSF) instead of secondary prophylaxis (SP) for elderly patients with diffuse aggressive lymphoma receiving chemotherapy. We examined the cost-effectiveness of PP when compared with SP.

METHODS

We conducted a cost-utility analysis to compare PP to SP for diffuse aggressive lymphoma. We used a Markov model with an eight-cycle chemotherapy time horizon with a government-payer perspective and Ontario health, economic, and cost data. Data for efficacies of G-CSF, probabilities, and utilities were obtained from published literature. Probabilistic sensitivity analysis (PSA) was conducted.

RESULTS

The incremental cost-effectiveness ratio of PP to SP was $700,500 per quality-adjusted life-year (QALY). One-way sensitivity analyses (willingness-to-pay threshold = $100,000/QALY) showed that if PP were to be cost-effective, the cost of hospitalization for febrile neutropenia (FN) had to be more than $31,138 (2.5 × > base case), the cost of G-CSF per cycle less than $960 (base case = $1,960), the risk of first-cycle FN more than 47% (base case = 24%), or the relative risk reduction of FN with G-CSF more than 91% (base case = 41%). Our result was robust to all variables. PSA revealed a 10% probability of PP being cost-effective over SP at a willingness-to-pay threshold of $100,000/QALY.

CONCLUSION

PP is not cost-effective when compared with SP in this population. PP becomes attractive only if the cost of hospitalization for FN is significantly higher or the cost of G-CSF is significantly lower.

Predictors of length of hospital stay after total hip replacement

PURPOSE

To identify variables affecting length of hospital stay after total hip replacement (THR) while controlling for potential confounders.

METHODS

Records of 199 consecutive elective unilateral THRs were reviewed. Clinical and demographic data including age, gender, body mass index, comorbidities, surgical factors (surgical approach, type of prosthesis, use of cement, operating time), anaesthetic factors (type of anaesthesia, ASA physical status), and length of hospital stay were recorded.

RESULTS

64% of patients left hospital within 12 days, 28% within 3 weeks, and 8% after 3 weeks. The median length of hospital stay was longer in women than men (11.5 vs. 9 days, p=0.009), in patients aged >65 years than those younger (13 vs. 9 days, p<0.0001), and in those with American Society of Anesthesiologists (ASA) grades 3 and 4 than grades 1 or 2 (14 vs. 9 days, p<0.0001). A greater proportion of women than men (45% vs. 27%, p=0.007), patients aged >65 years than those younger (61% vs. 37% or 24%, p<0.0001), and those with ASA grades 3 and 4 than grades 1 and 2 (68% vs. 25%, p<0.0001) stayed 12 days or longer. In the multiple regression analysis, the predictors for prolonged hospital stay (12 days or more) were patient age >65 years (p<0.003), female gender (p<0.05), and ASA grades 3 and 4 (p<0.0001). Of the 72 patients with prolonged stay, 7% had no, 26% had one, 42% had 2, and 25% had all 3 predictors.

CONCLUSION

Prolonged hospital stay after THR is largely predetermined by case mix. Our study helps to identify individuals who need longer rehabilitation and more care.

Pre-operative interventions (non-surgical and non-pharmacological) for patients with hip or knee osteoarthritis awaiting joint replacement surgery--a systematic review and meta-analysis

OBJECTIVE

To determine if pre-operative interventions for hip and knee osteoarthritis provide benefit before and after joint replacement.

METHOD

Systematic review with meta-analysis of randomised controlled trials (RCTs) of pre-operative interventions for people with hip or knee osteoarthritis awaiting joint replacement surgery. Standardised mean differences (SMD) were calculated for pain, musculoskeletal impairment, activity limitation, quality of life, and health service utilisation (length of stay and discharge destination). The GRADE approach was used to determine the quality of the evidence.

RESULTS

Twenty-three RCTs involving 1461 participants awaiting hip or knee replacement surgery were identified. Meta-analysis provided moderate quality evidence that pre-operative exercise interventions for knee osteoarthritis reduced pain prior to knee replacement surgery (SMD (95% CI)=0.43 [0.13, 0.73]). None of the other meta-analyses investigating pre-operative interventions for knee osteoarthritis demonstrated any effect. Meta-analyses provided low to moderate quality evidence that exercise interventions for hip osteoarthritis reduced pain (SMD (95% CI)=0.52 [0.04, 1.01]) and improved activity (SMD (95% CI)=0.47 [0.11, 0.83]) prior to hip replacement surgery. Meta-analyses provided low quality evidence that exercise with education programs improved activity after hip replacement with reduced time to reach functional milestones during hospital stay (e.g., SMD (95% CI)=0.50 [0.10, 0.90] for first day walking).

CONCLUSION

Low to moderate evidence from mostly small RCTs demonstrated that pre-operative interventions, particularly exercise, reduce pain for patients with hip and knee osteoarthritis prior to joint replacement, and exercise with education programs may improve activity after hip replacement.

The trajectory of recovery and the inter-relationships of symptoms, activity and participation in the first year following total hip and knee replacement

OBJECTIVE

Primary total hip (THR) and knee (TKR) replacement outcomes typically include pain and function with a single time of follow-up post-surgery. This research evaluated the trajectory of recovery and inter-relationships within and across time of physical impairments (PI) (e.g., symptoms), activity limitations (AL), and social participation restrictions (PR) in the year following THR and TKR for osteoarthritis.

DESIGN

Participants (hip: n=437; knee: 494) completed measures pre-surgery and at 2 weeks, 1, 3, 6 and 12 months post-surgery. These included PI (Hip Disability and Osteoarthritis Outcome Score (HOOS)/Knee Injury and Osteoarthritis Outcome Score (KOOS) symptoms and Chronic Pain Grade); AL (HOOS/KOOS activities of daily living and sports/leisure activities); and, PR (Late Life Disability and the Calderdale community mobility). Repeated measures analysis of variance (RANOVA) was used to evaluate the trajectory of recovery of outcomes and the inter-relationships of PI, AL and PR were evaluated using path analysis. All analyses were adjusted for age, sex, obesity, THR/TKR, low back pain and mood.

RESULTS

THR: age 31-86 years with 55% female; TKR: age 35-88 years with 65% female. Significant improvements in outcomes were observed over time. However, improvements were lagged over time with earlier improvements in PI and AL and later improvements in PR. Within and across time, PI was associated with AL and AL was associated with PR. The magnitude of these inter-relationships varied over time.

CONCLUSION

Given the lagged inter-relationship of PI, AL and PR, the provision and timing of interventions targeting all constructs are critical to maximizing outcome. Current care pathways focusing on short-term follow-up with limited attention to social and community participation should be re-evaluated.

Walking and chair rising performed in the daily life situation before and after total hip arthroplasty

OBJECTIVE

An earlier study showed that 6 months after total hip arthroplasty (THA) patients' overall daily activity level had not increased, despite significant improvement in their perceived physical functioning. This discrepancy might be because postoperative recovery is not expressed by a more overall active lifestyle, but by the fact that patients could perform the individual activities of daily living (ADL) faster and/or for a longer period of time. The aim of this study was to assess whether patients perform ADL faster and/or for a longer period of time 6 months post-THA compared to baseline. Also examined was whether patients perform activities on the level of healthy matched controls.

METHOD

Thirty patients were measured at home with an accelerometry-based Activity Monitor, pre-operatively and 6 months post-THA. Patients were matched with healthy controls on gender and age (±2 years).

RESULTS

Compared with baseline, 6 months post-THA the stride frequency and body motility during walking of patients had increased [56.1 (54.3, 57.8)strides/min vs 52.1 (50.3, 54.1)strides/min; P-value<0.0001, and 0.265 (0.245, 0.286)g vs 0.219 (0.197, 0.240)g; P-value<0.0001], and they rose faster from a chair [2.6 (2.5, 2.8)s vs 3.0 (2.8, 3.2)s; P-value<0.0001]. Compared with controls, preoperative all patients had lower values for these parameters. Six months post-THA the stride frequency and body motility during walking were similar to that of controls, but patients rose slower from a chair than controls.

CONCLUSION

Six months post-THA patients walked faster and rose from a chair faster compared to baseline. Patients walked as fast as healthy controls but took longer rising from a chair.

Quality of life and cost-effectiveness 1 year after total hip arthroplasty

Quality of life index (Quality Of Well-Being [QWB]) was used to calculate the costs per quality of well year (QWY) in total hip arthroplasty (THA) and compare it to other interventions. Ninety-eight primary and/or revision THA were reviewed. Patients had minimum 1-year follow-up. Quality of life index was used to calculate the costs per QWY in primary and revision THA. Preoperative QWB for primary THA was 0.52 ± 0.06 SD; revision was 0.53 ± 0.07 SD. The QWB change at 1 year for primary THA was 0.08 ± 0.13 SD; revision THA was 0.06 ± 0.14 SD. Calculated costs per QWY were $5572 for primary procedures and $10,775 for revision procedures. Cost-effectiveness of THA compares favorably with other surgical and medical interventions such as epilepsy ablation surgery and gastric bypass surgery.

Successful management of recalcitrant infection related to total hip replacement using pedicled rectus femoris or vastus lateralis muscle flaps

Deep prosthetic joint infection remains an uncommon but serious complication of total hip replacement. We reviewed 24 patients with recalcitrant hip wounds following infected total hip replacement treated with either pedicled rectus femoris or vastus lateralis muscle flaps between 1998 and 2009. The mean age of the patients was 67.4 years (42 to 86) with ten men and 14 women.

There had been a mean of four (1 to 8) previous attempts to close the wound. A total of 20 rectus femoris and five vastus lateralis flaps were used, with one of each type of flap failing and requiring further reconstruction. All patients had positive microbiology. At a mean follow-up of 47 months (9 to 128), 22 patients had a healed wound and two had a persistent sinus. The prosthesis had been retained in five patients. In the remainder it had been removed, and subsequently re-implanted in nine patients. Six patients continued to take antibiotics at final follow-up.

This series demonstrates the effectiveness of pedicled muscle flaps in healing these infected wounds. The high number of previous debridements suggests that these flaps could have been used earlier.

The use of a constrained cementless acetabular component for instability in total hip replacement

Recurrent dislocation after total hip arthroplasty is a disabling complication that can be difficult to treat. We evaluated the early clinical and radiographic outcome associated with the use of a constrained acetabular component for instability in total hip arthroplasty. Fifteen patients underwent either primary or revision total hip arthroplasty with a cementless constrained acetabular component for different indications. The mean patient age at surgery was 57.4 years and the mean clinical and radiological follow-up period was 26.4 months. Clinical assessment was performed by the Harris hip score and at the latest follow up patients reported outcome using the Oxford hip score questionnaire. All radiographs were evaluated for evidence of loosening. Only one patient experienced redislocation with the constrained prosthesis. The average Harris hip score increased from a preoperative mean of 22 (range, 16 - 36) to a postoperative mean of 85 (range, 66-94). Preoperatively, the mean Oxford Hip Score was 48.6, which decreased to 20.5 at the final examination. All but one of the 15 hips had a well-fixed, stable cup. Femoral component stability with bone ingrowth was achieved in 10 cases. A constrained acetabular component is an effective option for the treatment of hip instability in primary and revision arthroplasty in those at high risk of dislocation. The potential for aseptic loosening requires evaluation by long term studies.

What is a good patient reported outcome after total hip replacement?

OBJECTIVES

There is an increasing movement to collect and report patient reported outcome measures (PROM's) following total hip replacement (THR). In the UK, the procedure specific PROM of choice is the Oxford Hip Score (OHS). It is currently unclear how to use this information to determine outcome following surgery. The aim of this study was to define a threshold for the OHS that is correlated with patient satisfaction.

DESIGN

Prospective cohort study.

SETTING

A district general hospital (St. Helier Hospital, Carshalton, UK).

PARTICIPANTS

799 patients receiving THR from 1995 to 2004.

MAIN OUTCOME MEASURES

At 12 and 24 months after surgery patients were asked if they were satisfied with surgery and completed the OHS. Receiver operating characteristic (ROC) analyses were used to identify thresholds of follow-up OHS, which best discriminated patient satisfaction. Analyses were stratified by age, sex, body mass index (BMI), baseline OHS and patient expectations.

RESULTS

91.9% of patients were satisfied with THR at 12 months (92.8% at 24 months). Using the ROC technique, the OHS at 12 months associated with patient satisfaction was 38 and at 24 months 33. The OHS at 24 months associated with satisfaction was higher in those with highest tertile of baseline OHS (30, 33, 43 respectively), and lowest tertile of BMI.

CONCLUSIONS

We have identified a value of the OHS that predicts patient satisfaction 12-24 months following THR within a standard clinical setting. However, this threshold is markedly influenced by pre-operative OHS and should be stratified accordingly.

Cost effectiveness of the type II Boston keratoprosthesis

PURPOSE

Despite demonstrated cost effectiveness, not all corneal disorders are amenable to type I Boston keratoprosthesis (KPro) implantation. This includes patients with autoimmune diseases, such as Stevens-Johnson syndrome/toxic epidermal necrolysis. Type II KPro is implanted through the eyelids in severe dry eye and cicatricial diseases, and its cost effectiveness was sought.

PATIENTS AND METHODS

In a retrospective chart review, 29 patients who underwent type II KPro surgery at the Massachusetts Eye and Ear Infirmary between the years 2000 and 2009 were identified. A total of 11 patients had 5-year follow-up data. Average cost effectiveness was determined by cost-utility analysis, comparing type II KPro surgery with no further intervention.

RESULTS

Using the current parameters, the cost utility of KPro from third-party insurer (Medicare) perspective was 63,196 $/quality-adjusted life year .

CONCLUSION

Efforts to refer those less likely to benefit from traditional corneal transplantation or type I KPro, for type II KPro surgery, may decrease both patient and societal costs.

Total joint replacement in the elderly patient

Osteoarthritis of the hip and knee is extremely common in the growing elderly population. Total joint replacement (TJR) of the hip and knee are extremely effective procedures, resulting in decreased pain and improved function and quality of life in patients of all age groups including the elderly. The prevalence and use of TJR is increasing at a significant rate, therefore increased awareness of perioperative issues following TJR among health care providers is of paramount importance. Although elderly patients may be slightly more susceptible to perioperative complications, long-term success rates remain high, and careful perioperative monitoring and preventative measures have resulted in high rates of patient safety and few adverse outcomes in the elderly.

The influence of procedure volumes and standardization of care on quality and efficiency in total joint replacement surgery

BACKGROUND

The relationship between surgeon and hospital procedure volumes and clinical outcomes in total joint arthroplasty has long fueled a debate over regionalization of care. At the same time, numerous policy initiatives are focusing on improving quality by incentivizing surgeons to adhere to evidence-based processes of care. The purpose of this study was to evaluate the independent contributions of surgeon procedure volume, hospital procedure volume, and standardization of care on short-term postoperative outcomes and resource utilization in lower-extremity total joint arthroplasty.

METHODS

An analysis of 182,146 consecutive patients who underwent primary total joint arthroplasty was performed with use of data entered into the Perspective database by 3421 physicians from 312 hospitals over a two-year period. Adherence to evidence-based processes of care was defined by administration of appropriate perioperative antibiotic prophylaxis, beta-blockade, and venous thromboembolism prophylaxis. Patient outcomes included mortality, length of hospital stay, discharge disposition, surgical complications, readmissions, and reoperations within the first thirty days after discharge. Hierarchical models were used to estimate the effects of hospital and surgeon procedure volume and process standardization on individual and combined surgical outcomes and length of stay.

RESULTS

After adjustment in multivariate models, higher surgeon volume was associated with lower risk of complications, lower rates of readmission and reoperation, shorter length of hospital stay, and higher likelihood of being discharged home. Higher hospital volume was associated with lower risk of mortality, lower risk of readmission, and higher likelihood of being discharged home. The impact of process standardization was substantial; maximizing adherence to evidence-based processes of care resulted in improved clinical outcomes and shorter length of hospital stay, independent of hospital or surgeon procedure volume.

CONCLUSIONS

Although surgeon and hospital procedure volumes are unquestionably correlated with patient outcomes in total joint arthroplasty, process standardization is also strongly associated with improved quality and efficiency of care. The exact relationship between individual processes of care and patient outcomes has not been established; however, our findings suggest that process standardization could help providers optimize quality and efficiency in total joint arthroplasty, independent of hospital or surgeon volume.

Effect of Sociodemographic Factors on Surgical Consultations and Hip or Knee Replacements Among Patients with Osteoarthritis in British Columbia, Canada

Objective.

To quantify the effect of demographic variables and socioeconomic status (SES) on surgical consultation and total joint arthroplasty (TJA) rates among patients with osteoarthritis (OA), using population-based administrative data.

Methods.

A cohort study was conducted in British Columbia using population data from 1991 to 2004. From April 1996 to March 1998, we documented 34,420 new patients with OA and these patients were followed to March 2004 for their first surgical consultation and TJA. Effects of age, sex, and SES were evaluated by Cox proportional hazards models after adjusting for comorbidities and pain medication used.

Results.

During a mean 5.5-year followup period, 7475 patients with OA had their first surgical consultations and 2814 patients received TJA within a 6-year mean followup period. Crude hazards ratio (HR) for men compared to women was 1.25 (95% CI 1.20–1.31) for surgical consultation and was 1.14 (95% CI 1.06–1.23) for TJA. The interaction between sex and SES was significant. Stratified analysis showed among men an HR of 1.42 (95% CI 1.27–1.58) and 1.52 (95% CI 1.26–1.83) for surgical consultations and TJA, respectively, for the highest SES compared with the lowest SES quintiles. Similarly significant results were observed among women.

Conclusion.

Differential access to the healthcare system exists among patients with OA. Women with OA were less likely than men to see an orthopedic surgeon as well as to obtain TJA. Patients with higher SES consulted orthopedic surgeons more frequently and received more TJA than those with the lowest SES.

A population-based study of trends in the use of total hip and total knee arthroplasty, 1969-2008

OBJECTIVE

To study the rates of use of total hip arthroplasty (THA) and total knee arthroplasty (TKA) during the past 4 decades.

METHODS

The Rochester Epidemiology Project was used to identify all Olmsted County, Minnesota, residents who underwent THA or TKA from January 1, 1969, through December 31, 2008. We used a population-based approach because few data are available on long-term trends in the use of THA and TKA in the United States. Rates of use were determined by age- and sex-specific person-years at risk. Poisson regression was used to assess temporal trends by sex and age group.

RESULTS

The age- and sex-adjusted use of THA increased from 50.2 (95% confidence interval [CI], 40.5-59.8) per 100,000 person-years in 1969-1972 to 145.5 (95% CI, 134.2-156.9) in 2005-2008, whereas TKA increased markedly from 31.2 (95% CI, 25.3-37.1) per 100,000 person-years in 1971-1976 to 220.9 (95% CI, 206.7-235.0) in 2005-2008. For both procedures, use was greater among females, and the rate generally increased with age.

CONCLUSION

In this community, TKA and THA use rates have increased steadily since the introduction of the procedures and continue to increase for all age groups. On the basis of these population-based data, the probable need for TKA and THA exceeds current federal agency projections.

Cost-effectiveness of exercise and diet in overweight and obese adults with knee osteoarthritis

PURPOSE

The purpose of this study was to compare the cost-effectiveness of dietary and exercise interventions in overweight or obese elderly patients with knee osteoarthritis (OA) enrolled in the Arthritis, Diet, and Physical Activity Promotion Trial (ADAPT).

METHODS

ADAPT was a single-blinded, controlled trial of 316 adults with knee OA, randomized to one of four groups: Healthy Lifestyle Control group, Diet group, Exercise group, or Exercise and Diet group. A cost analysis was performed from a payer perspective, incorporating those costs and benefits that would be realized by a managed care organization interested in maintaining the health and satisfaction of its enrollees while reducing unnecessary utilization of health care services.

RESULTS

The Diet intervention was most cost-effective for reducing weight, at $35 for each percentage point reduction in baseline body weight. The Exercise intervention was most cost-effective for improving mobility, costing $10 for each percentage point improvement in a 6-min walking distance and $9 for each percentage point improvement in the timed stair climbing task. The Exercise and Diet intervention was most cost-effective for improving self-reported function and symptoms of arthritis, costing $24 for each percentage point improvement in subjective function, $20 for each percentage point improvement in self-reported pain, and $56 for each percentage point improvement in self-reported stiffness.

CONCLUSIONS

The Exercise and Diet intervention consistently yielded the greatest improvements in weight, physical performance, and symptoms of knee OA. However, it was also the most expensive and was the most cost-effective approach only for the subjective outcomes of knee OA (self-reported function, pain, and stiffness). Perceived function and symptoms of knee OA are likely to be stronger drivers of downstream health service utilization than weight, or objective performance measures and may be the most cost-effective in the long term.

Educational needs of patients undergoing total joint arthroplasty

PURPOSE

To identify the educational needs of adults who undergo total hip and total knee replacement surgery.

METHODS

A qualitative research design using a semi-standardized interviewing method was employed. A purposive sampling technique was used to recruit participants, who were eligible if they were scheduled to undergo total hip or total knee replacement or had undergone total hip or total knee replacement in the previous 3 to 6 months. A comparative contrast method of analysis was used.

RESULTS

Of 22 potential participants who were approached, 15 participated. Five were booked for upcoming total hip or total knee replacement and 10 had undergone at least one total hip or total knee replacement in the previous 3 to 6 months. Several themes related to specific educational needs and factors affecting educational needs, including access, preoperative phase, surgery and medical recovery, rehabilitation process and functional recovery, fears, and expectations counterbalanced with responsibility, emerged from the interviews.

CONCLUSIONS

Educational needs of adults who undergo total hip and knee replacement surgery encompass a broad range of topics, confirming the importance of offering an all-inclusive information package regarding total hip and total knee replacement.

Decreased periprosthetic bone loss in patients treated with clodronate: a 1-year randomized controlled study

The efficacy of clodronate to reduce bone loss around uncemented stems after total hip arthroplasty(THA) was evaluated. Ninety-one patients operated with uncemented THA were randomized to receive either intramuscular clodronate at a dose of 100 mg weekly for 12 months or no treatment. Periprosthetic and contralateral bone mineral density (BMD) scans were performed and biochemical markers of bone turnover measured at baseline and at 3, 6, and 12 months. At month 12, with the exception of Gruen zones 4 and 5, patients treated with clodronate showed less bone loss at all zones, reaching statistical significance (P\0.05) in Gruen zones 2 and 6 (difference of 6.6 and 5.9%, respectively). Analysis of data according to gender revealed sex-related differences in bone loss and efficacy of treatment. After 12 months, the difference in bone loss between treated and untreated women in five out of seven Gruen zones ranged from 6.2 to 13.3% (SS at zones 2 and 6), whereas comparison between treated and untreated men showed no BMD differences in all zones(P[0.05). Median percent changes in serum levels of markers of bone metabolism by gender were consistent with BMD changes. A 1-year treatment with intramuscular clodronate determined a significant reduction of bone loss after THA. This was mainly attributed to its greater efficacy in the female population, which is at higher risk for bone loss. This observation suggests the need for the characterization of high-risk subjects as potential candidates for prevention strategies.

OARSI recommendations for the management of hip and knee osteoarthritis: part III: Changes in evidence following systematic cumulative update of research published through January 2009

OBJECTIVE

To update evidence for available therapies in the treatment of hip and knee osteoarthritis (OA) and to examine whether research evidence has changed from 31 January 2006 to 31 January 2009.

METHODS

A systematic literature search was undertaken using MEDLINE, EMBASE, CINAHL, AMED, Science Citation Index and the Cochrane Library. The quality of studies was assessed. Effect sizes (ESs) and numbers needed to treat were calculated for efficacy. Relative risks, hazard ratios (HRs) or odds ratios were estimated for side effects. Publication bias and heterogeneity were examined. Sensitivity analysis was undertaken to compare the evidence pooled in different years and different qualities. Cumulative meta-analysis was used to examine the stability of evidence.

RESULTS

Sixty-four systematic reviews, 266 randomised controlled trials (RCTs) and 21 new economic evaluations (EEs) were published between 2006 and 2009. Of 51 treatment modalities, new data on efficacy have been published for more than half (26/39, 67%) of those for which research evidence was available in 2006. Among non-pharmacological therapies, ES for pain relief was unchanged for self-management, education, exercise and acupuncture. However, with new evidence the ES for pain relief for weight reduction reached statistical significance, increasing from 0.13 [95% confidence interval (CI) -0.12, 0.36] in 2006 to 0.20 (95% CI 0.00, 0.39) in 2009. By contrast, the ES for electromagnetic therapy which was large in 2006 (ES=0.77, 95% CI 0.36, 1.17) was no longer significant (ES=0.16, 95% CI -0.08, 0.39). Among pharmacological therapies, the cumulative evidence for the benefits and harms of oral and topical non-steroidal anti-inflammatory drugs, diacerhein and intra-articular (IA) corticosteroid was not greatly changed. The ES for pain relief with acetaminophen diminished numerically, but not significantly, from 0.21 (0.02, 0.41) to 0.14 (0.05, 0.22) and was no longer significant when analysis was restricted to high quality trials (ES=0.10, 95% CI -0.0, 0.23). New evidence for increased risks of hospitalisation due to perforation, peptic ulceration and bleeding with acetaminophen >3g/day have been published (HR=1.20, 95% CI 1.03, 1.40). ES for pain relief from IA hyaluronic acid, glucosamine sulphate, chondroitin sulphate and avocado soybean unsponifiables also diminished and there was greater heterogeneity of outcomes and more evidence of publication bias. Among surgical treatments further negative RCTs of lavage/debridement were published and the pooled results demonstrated that benefits from this modality of therapy were no greater than those obtained from placebo.

CONCLUSION

Publication of a large amount of new research evidence has resulted in changes in the calculated risk-benefit ratio for some treatments for OA. Regular updating of research evidence can help to guide best clinical practice.

Temporal trends in primary total hip and knee arthroplasty surgery: results from a UK regional joint register, 1991-2004

INTRODUCTION

The aim of this study was to evaluate temporal trends in the prevalence of primary total hip and knee replacements (THRs and TKRs) throughout the Trent region from 1991 to 2004.

PATIENTS AND METHODS

The Trent Regional Arthroplasty Study records details of primary THR and TKR prospectively and data from the register were examined. Age and gender population data were provided by the Office for National Statistics.

RESULTS

A total of 26,281 THRs and 23,606 TKRs were recorded during this period. Analysis showed that females had an increased incidence rate ratio (IRR) for both primary THR (IRR = 1.29; 95% CI 1.26-1.33; P < 0.001) and TKR (IRR = 1.17; 95% CI 1.14-1.20; P < 0.001). Patients aged 74-85 years had the largest IRR for both primary THR (IRR = 6.7; 95% CI 6.4-7.0; P < 0.001) and TKR (IRR = 15.3; 95% CI 14.4-16.3; P < 0.001).

CONCLUSIONS

The prevalence of primary TKR increased significantly over time whereas THR remained steady in the Trent region between 1991 and 2004.

A cost-utility analysis of nonsurgical management, total wrist arthroplasty, and total wrist arthrodesis in rheumatoid arthritis

PURPOSE

Management of end-stage rheumatoid wrist disease remains controversial. Total wrist arthrodesis provides reliable pain relief and stability and is the most commonly applied management strategy. Total wrist arthroplasty is a motion-preserving alternative that is gaining popularity. The purpose of this study was to perform a cost-utility analysis comparing nonsurgical management, total wrist arthroplasty, and total wrist arthrodesis for the rheumatoid wrist.

METHODS

A time trade-off utility survey was developed to investigate patient and physician preferences for the potential outcomes of total wrist arthroplasty and total wrist arthrodesis. The study sample consisted of rheumatoid patients (N = 49) recruited as part of an ongoing prospective study and a national random sample of hand surgeons and rheumatologists (N = 109). A decision tree was created using utility values derived from the survey, and the expected quality-adjusted life-years (QALYs) for each procedure were determined. Using the societal perspective, costs were based on the Medicare fee schedules for the Current Procedural Terminology codes associated with total wrist arthroplasty and total wrist arthrodesis and their potential complications. Costs per QALY were calculated and compared.

RESULTS

Patients and physicians both showed a preference for surgical management over nonsurgical management. Application of cost data indicated that the incremental cost per additional QALY gained for total wrist arthroplasty over nonsurgical management was $2,281 and the incremental cost per QALY gained with total wrist arthroplasty over total wrist arthrodesis was $2,328, which is substantially less than the national standard of $50,000/QALY deemed acceptable for adoption.

CONCLUSIONS

In the absence of rigorous outcome data, cost-utility analysis is a useful tool to guide treatment decisions. Total wrist arthroplasty and total wrist arthrodesis are both extremely cost-effective procedures. This study incorporated patient and physician utilities to demonstrate that total wrist arthroplasty has only a small incremental cost over the traditional total wrist arthrodesis procedure. Based on this economic model, total wrist arthroplasty may be worthy of further consideration, and cost should not be considered prohibitive.

TYPE OF STUDY/LEVEL OF EVIDENCE

Decision Analysis II.

Complications for racial and ethnic minority groups after total hip and knee replacement: a review of the literature

BACKGROUND

Total hip and knee replacement reduces disability associated with lower extremity osteoarthritis. It has been shown that racial and ethnic minority groups underutilize these procedures; however, little information exists on postoperative outcomes for ethnic minorities.

METHODS

We conducted a systematic review of the literature to compile population-based or multicenter studies on early postoperative outcomes after total hip and knee replacement in racial and ethnic minorities.

RESULTS

Nine studies met the inclusion criteria. Among the nine eligible studies, four examined total knee replacement, three examined total hip replacement, and two examined both. Two studies investigated mortality after total knee replacement, and one found that blacks had an increased risk of mortality. Three studies investigated infection after total knee replacement; all found an increased risk in blacks and Hispanics. Four studies examined non-infection-related complications after total knee replacement, and all four found that nonwhites had an increased risk of complications. Two studies investigated mortality after total hip replacement; one of these found that, for primary hip replacement, blacks had an increased risk of mortality.

CONCLUSIONS

There is a paucity of research on outcomes after orthopaedic procedures for racial and ethnic minority groups. On the basis of the available literature, racial and ethnic minority groups appear to have a higher risk for early complications (those occurring within ninety days), particularly joint infection, after total knee replacement and perhaps a higher risk of mortality after total hip replacement.

Two-stage revision for prosthetic joint infection: predictors of outcome and the role of reimplantation microbiology

Objectives

We describe rates of success for two-stage revision of prosthetic joint infection (PJI), including data on reimplantation microbiology.

Methods

We retrospectively collected data from all the cases of PJI that were managed with two-stage revision over a 4 year period. Patients were managed with an antibiotic-free period before reimplantation, in order to confirm, clinically and microbiologically, that infection was successfully treated.

Results

One hundred and fifty-two cases were identified. The overall success rate (i.e. retention of the prosthesis over 5.75 years of follow-up) was 83%, but was 89% for first revisions and 73% for re-revisions [hazard ratio = 2.9, 95% confidence interval (CI) 1.2–7.4, P = 0.023]. Reimplantation microbiology was frequently positive (14%), but did not predict outcome (hazard ratio = 1.3, 95% CI 0.4–3.7, P = 0.6). Furthermore, most unplanned debridements following the first stage were carried out before antibiotics were stopped (25 versus 2 debridements).

Conclusions

We did not identify evidence supporting the use of an antibiotic-free period before reimplantation and routine reimplantation microbiology. Re-revision was associated with a significantly worse outcome.

The effect of total hip arthroplasty on employment

This study was undertaken to investigate the impact of total hip arthroplasty on a patient's work ability. Fifty-four patients who were in the workforce completed a questionnaire 1 year after total hip arthroplasty. Thirty-eight (86%) of 44 patients working preoperatively were working 1 year after surgery, whereas only 2 (20%) of 10 patients who were not working preoperatively resumed work. Those who resumed work were younger and reported better Oxford-12 and physical function scores. Patients who resumed working had improvements in their ability to meet workplace physical demands and in productivity. Total hip arthroplasty has positive effects on work capacity in patients who return to work. To help patients remain in the workforce, surgery should be undertaken before a patient's hip dysfunction forces them off work.

Modeling the cost-effectiveness for cement-less and hybrid prosthesis in total hip replacement in Emilia Romagna, Italy

BACKGROUND

The aim of the present study was to assess the cost-effectiveness of cement-less versus hybrid prostheses in total hip replacement (THR) in patients diagnosed with primary osteoarthritis.

METHODS

Effectiveness data were obtained from the Emilia-Romagna Regional Registry on Orthopaedic Prosthesis (RIPO), which collects information on all orthopaedic intervention performed in Emilia-Romagna (41,199 total hip replacements performed from 2000 to 2007), and from which we obtained survival curves and transition probabilities for the cement-less and hybrid prostheses, respectively. Conversely, costs were derived from regional databases through a specific procedure, which allowed us to register individual component's costs for both primary and subsequent revision interventions. A specific Markov transition model was constructed in order to consider the 3 types of revisions that an implant could possibly undergo through its life-span: total, cup or stem, head insert or neck. The cost-effectiveness was expressed in terms of cost per "revision-free" life year.

RESULTS AND CONCLUSIONS

Considering a 70-y old patient undergoing THR, the cementless strategy resulted more effective but more costly than the hybrid solution, with an incremental cost effectiveness ratio of 2401.63 € per revision-free life year. Following a deterministic sensitivity analysis, hybrid and cementless fixation showed, respectively, a dominance profile for patients older than 83 y and younger than 43 y, whereas for all ages in between, we report a progressive increase in the ICER of cementless prostheses. Our results proved to be robust, as underlined by the probabilistic sensitivity analysis performed using cost distributions.

Adverse events after total knee arthroplasty: a national Medicare study

Adverse events from 2033 total knee arthroplasty patients were documented by nonphysician abstractors. The annual rate of adverse events from 2002 to 2004 was 9.2%, 6.4%, and 5.8%, respectively. Congestive heart failure (odds ratio, 2.1; 95% confidence interval, 1.2-3.5; P < .01) and chronic obstructive pulmonary disease (odds ratio, 1.8; 95% confidence interval, 1.2-2.7; P < .01) were associated with a significantly increased risk of experiencing any adverse event during the index hospitalization. The 30-day postprocedure rate of readmission for all causes was 5.5%. Experiencing an adverse event during the index hospitalization increased the length of stay (P < .001). The rate of symptomatic venous thromboembolism 30 days postprocedure was 1.7%. The 30-day postprocedure mortality rate was 0.3%. Experiencing any adverse event was associated with an increased 30-day postprocedure mortality (P < .001). Compared with previous studies of Medicare claims, these data reveal a substantial decrease in the mortality rate, an increased readmission rate, and no substantial change in the rate of venous thromboembolism.

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.