Variations in the pre-operative status of patients coming to primary hip replacement for osteoarthritis in European orthopaedic centres.

BACKGROUND: Total hip joint replacement (THR) is a high volume, effective intervention for hip osteoarthritis (OA). However, indications and determinants of outcome remain unclear. The 'EUROHIP consortium' has undertaken a cohort study to investigate these questions. This paper describes the variations in disease severity in this cohort and the relationships between clinical and radiographic severity, and explores some of the determinants of variation. METHODS: A minimum of 50 consecutive, consenting patients coming to primary THR for primary hip OA in each of the 20 participating orthopaedic centres entered the study. Pre-operative data included demographics, employment and educational attainment, drug utilisation, and involvement of other joints. Each subject completed the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC - Likert version 3.1). Other data collected at the time of surgery included the prosthesis used and American Society of Anaesthesiologists (ASA) status. Pre-operative radiographs were read by the same three readers for Kellgren and Lawrence (K&L) grading and Osteoarthritis Research Society International (OARSI) atlas features. Regression analyses were carried out. RESULTS: Data from 1327 subjects has been analysed. The mean age of the group was 65.7 years, and there were more women (53.4%) than men. Most (79%) were ASA status 1 or 2. Reported disease duration was 5 years or less in 69.2%. Disease in other joint sites was common.Radiographs were available in 1051 subjects and the K&L grade was 3 or 4 in 95.8%. There was much more variation in clinical severity (WOMAC score); the mean total WOMAC score was 59.2 (SD 16.1). The radiographic severity showed no correlation with WOMAC scores.Significantly higher WOMAC scores (worse disease) were seen in older people, women, those with obesity, those with worse general health, and those with lower educational attainment. CONCLUSION: 1. Clinical disease severity varies widely at the time of THR for OA. 2. In advanced hip OA clinical severity shows no correlation with radiographic severity. 3. Simple scores of pain and disability do not reflect the complexity of decision-making about who should have a THR.

The Influence of Arthritis in Other Major Joints and the Spine on the One-Year Outcome of Total Hip Replacement: A Prospective, Multicenter Cohort Study (EUROHIP) Measuring the Influence of Musculoskeletal Morbidity.

BACKGROUND: Although arthritis in other affected major joints and back pain are known to lead to worse outcomes following total hip replacement, to our knowledge, these risk factors have not previously been operationalized as a musculoskeletal morbidity profile. The aim of this study was to measure the influence of other major joints and the spine (as grades of musculoskeletal morbidity) on the 1-year outcome of primary total hip replacement. METHODS: The EUROHIP study consists of 1,327 patients undergoing primary total hip replacement for arthritis across 20 European orthopaedic centers. The primary outcome was the responder rate at 12 months calculated with the relative effect per patient for total hip replacement using the total Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score. The primary predictor of interest was different combinations of arthritis of major joints and the spine grouped into 4 musculoskeletal morbidity grades: 1 (single major joint), 2 (multiple major joints), 3 (single major joint and spine), and 4 (multiple major joints and spine). The confounders adjusted for were age, sex, body mass index, living situation, years of hip pain, American Society of Anesthesiologists (ASA) class, anxiety or depression, and preoperative WOMAC subscales. RESULTS: For this analysis, 845 patients were included with complete 12-month follow-up WOMAC scores. The mean patient age was 65.7 years, and 55.2% of patients were female. CONCLUSIONS: The involvement of other major joints and the spine assessed as 1 of 4 musculoskeletal morbidity grades had a strong influence on the 1-year outcome after total hip replacement. The effect size was large compared with other risk factors. Even so, the majority of patients in musculoskeletal morbidity grade 4 had favorable outcomes from the surgical procedure (>74% response to surgical procedures). LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Patient-reported outcomes one year after primary hip replacement in a European Collaborative Cohort.

OBJECTIVE: To identify whether patients have symptomatic improvement 12 months following total hip replacement (THR) surgery. METHODS: The European Collaborative Database of Cost and Practice Patterns of Total Hip Replacement study consists of 1,327 patients receiving primary THR for osteoarthritis (OA) across 20 European orthopedic centers. The primary outcome was the difference in Western Ontario and McMaster Universities OA Index (WOMAC) score between preoperative and 12-month postoperative measurements. To classify whether patients responded to THR at 12 months, we used return to normal, Outcome Measures in Rheumatology Clinical Trials (OMERACT)-OA Research Society International (OARSI) criteria, minimum important difference (MID), and minimum clinically important difference. Exposures were age, sex, obesity, employment, educational attainment, American Society of Anesthesiologists status, and radiographs. RESULTS: On average, there was a large improvement in WOMAC scores 12 months after surgery, but whereas some patients improved, others got worse. The OMERACT-OARSI method classified 85.7% of patients as responders, MID 70.1%, and return to normal 64.1%. In general, each approach classified the same groups of patients as responding to THR. Based on total WOMAC score, patients who were younger, morbidly obese, employed, and better educated were more likely to respond to THR, but the effects were attenuated after adjustment for confounding, with only the effect of education remaining important. CONCLUSION: The overall average response to THR was good, but approximately 14-36% of patients did not improve, or were worse, 12 months postsurgery. Although the OMERACT-OARSI criteria were originally designed for use in clinical drug trials, they performed well in classifying patient response 12 months post-THR. Further research is required to understand the determinants of patient outcomes following THR.