The aim was to investigate whether or not the pre-operative injection of cortico-steroids into the knee influences the infection rate of a subsequent total knee replacement.

This was a case controlled study, in which it was calculated that 152 controls and 38 infected cases would give sufficient power to the study. The infection group had to have had a delay in wound healing or have had a revision for infection.

A total of 32.8% had had an injection at some time pre-operatively. The average number of injections was 2.23, with a range of 1–15. 37% were performed by a G.P., 35% by an orthopaedic surgeon, and 22% by a rheumatologist.79% had the injection within 12 months of surgery. The rate of injection was the same in the two groups. There was no significant difference in the infection rate between the two groups (OR 1.38; 95%CI 0.55–3.31)

Despite recent literature indicating that there is a 10% increase in infection in patients having steroid injections into the hip prior to THR this study does not confirm this risk in patients undergoing TKR.

To assess if highly cross-linked polyethylene is associated with less linear wear than ultra high molecular weight polyethylene in vivo.

To assess whether alteration in biomechanical characteristics of the reconstructed hip influence’s wear patterns.

A randomised prospective trial comparing conventional polyethylene with highly cross-linked polyethylene in an acetabular component was designed. Identical cemented stems were used in all cases, with a metal head. The polyethylene thickness was controlled. The trial design required 124 cases to be entered to give the study sufficient power to determine any difference in wear rates. Polyware Auto was used to assess 2D wear rate and volume.

This paper presents the preliminary results of the early patients entered into the study and looks at both 2D wear or creep at 18 months post operatively, and seeks to establish any relationships between 2D movement and biomechanical characteristics of the reconstructed hip.

There was no significant difference in the 2D wear (or creep) between the two types of polyethylene at 18 months. There was no correlation between femoral offset, cup offset, or centre of rotation offset and 2D wear (or creep).

This preliminary data shows no difference in the early wear rate of the two types of polyethylene. This is in contrast to an in vitro wear simulator study that has shown more creep in highly cross-linked polyethylene. The significance of this observation is unclear. We hope to demonstrate that as the trial progresses any difference in the performance of the two types of polyethylene should be evident.

Introduction: Hip fractures in the elderly create an economic and social burden on individuals and society. Earlier predictions of the incidence of hip fractures in the older adult population showed that by the year 2011 the rate would rise to epidemic proportions.

Aim: To analyse the actual hip fracture rate from 1988 to 1999 and then to compare it with the hip fracture rate predicted by Rockwood, Horne and Cryer in 1990.

Method: Data on the number of patients admitted to New Zealand hospitals with a diagnosis of fractured neck of femur were obtained, and compared with Rockwood’s (1990) weighted regression and baseline predictions. Poisson regression was used to test for changes in hip fracture rates over time.

Results: The numbers of hip fractures for females, from 1988 to 1993, were similar to the numbers predicted, yet have been significantly lower than stated predictions since 1995 (all age bands, P < 0.002; in the 85+ group, p < 0.0001). For males, hip fracture numbers are closer to those predicted, and since 1995 are less than the weighted regressions predicted. The difference was not statistically significant.

Conclusions: Despite the absence of a nationally agreed and coordinated strategy aimed at osteoporosis prevention, it appears that the use of risk assessments, osteoporosis prevention strategies, in combination with improved retirement home and personal care interventions and treatments are likely to have contributed to this situation. The 4.6% drop in the age group most at risk of hip fracture (85+), may be a contributing factor.