Hip resurfacing with metal-on-metal in patients with osteonecrosis (ON) raises concerns of early failure. This study addresses the hypothesis that osteonecrosis as a pre-operative diagnosis significantly increases the risk of failure following hip resurfacing. We analyzed data of 202 hips that underwent metal-on-metal hip resurfacing. In group 1 were 101 hips with a pre-operative diagnosis of osteonecrosis. In group 2 were 101 hips with other pre-operative diagnosis of osteoarthritis. Survival analysis with Cox regression was used to compare the revision risks of both groups. The mean age at operation was 42 years in osteonecrotic and 43 years in osteoarthritic group. The preoperative and postoperative hip scores were 62 and 96 for osteonecrotic group and 58 and 95 for osteoarthritic group, respectively. Survival analysis with revision for any reason as the endpoint was performed on the two groups which had identical follow-up periods. Survival at 10 years was 97.7% for osteonecrosis and 95.0% for osteoarthritis. The revision risk for patients with osteonecrosis was lower (0.37, 95% CI 0.07 – 1.82, Cox regression) but the difference was not significant (p = 0.19). Our study found no difference in revision risk in patients with osteonecrosis as compared to those with osteoarthritis

Between January 2000 and December 2007, 31 patients 90 years of age or older underwent total hip replacement at our hospital. Their data were collected prospectively. The rate of major medical complications was 9%. The surgical re-operation rate was 3%. The requirement for blood transfusion was 71% which was much higher than for younger patients. The 30-day, one-year and current mortality figures were 6.4% (2 of 31), 9.6% (3 of 31) and 55% (17 of 31), respectively, with a mean follow-up for the 14 surviving patients of six years. Cox’s regression analysis revealed no significant independent predictors of mortality. Only 52% of patients returned immediately to their normal abode, with 45% requiring a prolonged period of rehabilitation.

This is the first series to assess survival five years after total hip replacement for patients in their 90th year and beyond. Hip replacement in the extreme elderly should not be discounted on the grounds of age alone, although the complication rate exceeds that for younger patients. It can be anticipated that almost half of the patients will survive five years after surgery.

Introduction: Hip resurfacing is a renaissance of metal on metal hip arthroplasty. It preserves bone stock and a large head allows greater range of motion. This new technique is gaining popularity among patients and surgeons alike. We present a nine year follow up in the context of survival, function and complications.

Methods: We analysed follow up data of 4778 patients who have had hip resurfacing using Birmingham Hip resurfacing (Smith & Nephew, UK) in 37 countries. Patients were followed up annually using Oswestry hip score and any revisions were updated on the database at the Oswestry Outcome Centre. Function was analysed using multilevel modelling and Kaplan-Meier method used for survival analysis.

Results: There were 3193 males and 1585 females operated by 138 surgeons in 37 countries. The mean age was 52.8 years (13 – 87.8). Using hierarchical regression the annual hip scores were analysed. Overall function was significantly affected by pre op score and gender (p< 0.01). Age at operation had no effect on outcome score (p =.462).

We observed similar effect in individual domains of pain, mobility and range of motion. Survival of the implant at nine years with revision due to any reason was 93.5%. We observed a significant difference in survival of procedures done by pioneer surgeons and by non pioneering surgeons (p < 0.01) (log rank test). There were 119 complications of which there were 30 fractures, 21 occurring within the first six months of operation.

Conclusion: Nine year results of hip resurfacing arthroplasty look promising and are comparable to traditional hip arthroplasty. The difference between two surgeon groups could be due to a learning curve in the technique. Further follow up would be necessary to ascertain the long-term clinical effectiveness of this technique.

Introduction: Total hip replacement in one of the most commonly performed operation in orthopaedics in the UK with similar numbers being operated in other parts of the world (2). The main reasons for this magnitude are marked improvement in function and the quality of life. The hip prosthesis has evolved significantly over half a century and better prostheses are available today. These newer implants are required to have a survival of 90% for a minimum of 10 years. The improved survival of the implant tends to have effect on the quality of life as well as the life expectancy. There has been a continuous attempt to quantify this increased life expectancy and survival following total hip arthroplasty.

Materials and Methods: We compared the mortality figures of 3947 patients who had hip resurfacing arthroplasty with the national mortality figures of the UK. The cause of death was determined by telephone call to the next of kin and from the national death register.

Results: The average standardized mortality ratio of hip resurfacing patients compared to national figures over the nine year period was 0.524(99 percent C.I. 0.39 to 0.69). Individual SMR for each year is shown in Table. The number of observed deaths were 86 as compared to the expected deaths number 164. Out of the total 86 deaths over a nine year period, 36 deaths were due to cancer, 25 due to cardiovascular causes, eight due to respiratory conditions, four following accidents and 13 due to other causes such as suicide, old age. In the cancer group 7 patients died of lung cancer and 8 died of blood cell neoplasms. National figures for year 2007 were not yet compiled so SIR for cancer was not calculated.

Conclusion: The results of this study are comparable to other follow up studies on mortality following total hip replacement. This indicates that increased activity following hip resurfacing may help the patients maintain better fitness.

The incidence of cancer needs to be interpreted with caution and can only be ascertained by a prospective study.

Objective: Assessment of hip function is done by surgeon and few patient based tools. These patient assessed scores do not measure range of motion. The American Academy of Orthopaedic Surgeons has outlined pain, mobility and range of motion as three fundamental aspects of joint assessment. We aimed to validate Oswestry hip score which was developed as a patient-completed self-assessment to provide both Harris hip score and Merle d’Aubigne hip score with added content to estimate hip range of motion.

Methods: 144 patients completed the Oswestry hip score, WOMAC Index and the Oxford hip score at two different occasions. The patients were seen two weeks later and filled the Oswestry hip score and a surgeon filled the Harris hip score. The study included 80 females and 64 males with a mean age of 62 years range (32–91). We assessed the reliability, validity and responsiveness of this new tool by comparing the individual domains of the Oswestry hip score to similar domains of the WOMAC, Harris hip score and Oxford hip score.

Results: The reliability of this new score was established by the Intraclass Correlation Coefficient. Internal consistency was measured by Cronbach’s alpha. The Cronbach’s alpha was 0.7, which is considered a good measure of internal consistency. Content validity of the Oswestry hip score was established by the validated domains of pain, function and range of motion of the Harris hip score. Analysis of frequency of response distribution showed normal floor and ceiling effect for any of the domains of the Oswestry hip score. Multi-method multitrait matrix analysis was used to establish the construct validity of the Oswestry hip score. There was good correlation between pain and function domains (p< 0.001). Moderate correlation was found among clinical assessment of hip movement and movement domains of Oswestry hip score (Pearson’s r=0.55; p0.001). The responsiveness of the Oswestry hip score was measured with Cohen’s effect size. An effect size of > 0.8 is considered large. The mean effect size was 2.06 (1.36–2.97).

Conclusion: A positive construct validity and high correlation with WOMAC, Oxford Hip Score and Harris hip score shows that the Oswestry hip score can give an adequate measure of hip joint function. An effect size of 2.0 shows good responsiveness of the Oswestry hip score. The Oswestry hip score can be completed by patients themselves and is therefore ideal for long-term and large scale collection of clinical outcome data.

Objective: The aim of this study was to validate Oswestry hip score. This is a new score which was developed as a patient completed self-assessment to provide both Harris and Merle d’Aubigne hip score with added content to estimate hip range of motion.

Methods: 61 patients completed the Oswestry hip score, the WOMAC and the SF-36. Validity was tested by comparing the domains and items of the Oswestry hip score to WOMAC and SF-36. The new movement scale of Oswestry hip score was specifically validated against Merle d’ Aubinge, mobility scoring system. SPSS software was used for statistical analysis.

Results: Mean age was 56 years (range 18–83).Content validity of the Oswestry hip score was demonstrated by two main indicators for hip surgery, pain and function. Analysis of frequency of response distribution showed no floor or ceiling effect for any of the domains of the Oswestry hip score. Construct validity of the Oswestry hip score domains of pain and function showed good correlation with the correspondent domains of WOMAC and SF-36 (p< 0.001). Moderate correlation was found among clinical assessment of hip movement, Merle d’ Aubinge mobility score and movement domains of Oswestry hip score (Pearson’s r=0.55; p0.001). Correlation between Harris and Oswestry hip score was 0.63 to 0.91. Cronbach’s alpha was 0.7, showing good internal consistency.

Conclusion: A positive construct validity and high correlation with WOMAC and SF-36 shows that the Oswestry hip score is can give an adequate measure of hip joint function. The new questionnaire is brief and can be completed by patients themselves. It is therefore ideal for long-term and large-scale collection of data. Oswestry hip score does not intend to replace the clinical examination at the critical phases following hip surgery but can be a useful adjunct. We report the validity and reliability of this new tool.