Zirconium total knee replacements theoretically have a low incidence of failure as they are low friction, hard wearing and hypo allergenic; we present the five year survival data.

Data was collected prospectively from 212 patients who underwent Profix zirconium total knee replacements with an all-polyethylene tibial component. Revision surgery or a Knee Society Roentgenographic Evaluation System (KSRES) score of 10 or more was considered failure. SF 12 and WOMAC scores were recorded preoperatively, at three months, at one year, at three years and at five years. KSRES scores were recorded at all postoperative intervals.

There were 92 male and 120 female patients with a median age of 63 years, range 25 to 87. 188 implants were for osteoarthritis and 24 were for rheumatoid arthritis. Eight patients died and six were lost to follow up, the remaining 198 patients reached a minimum of five year follow-up.

At five years, the mean WOMAC score improved from 56 to 35 and the mean SF12 physical component score improved from 28 to 34. The mean SF12 mental component score remained unchanged at 51.

The five year survival with failure due to implant related reasons was 99.5% (95% CI 97.3 - 100). This was due to one tibial component becoming aseptically loose in the first year.

Reoperations excluded from this analysis were downsizing of the tibial component for stiffness and patella resurfacing. When these were included the five year survival was 98.1% (95% CI 95.1 - 99.3).

Our results demonstrate that the Profix zirconium total knee replacement has a low medium term failure rate comparable to the best implants. Further research is needed to establish if the beneficial properties of zirconium improve long term implant survival.

Introduction: We assessed the correlation between the International Prostate Symptom Score (IPSS), patient age and incidence of post-operative catheterisation for retention in patients undergoing total hip replacement.

Methods And Results: 140 patients, 60 male and 80 female, admitted for total hip replacements between August 2005 and March 2006 were included. Pre-operatively patients were scored by the IPSS (0–35) according to the severity of their urinary symptoms. Patients were categorised into three symptom groups (mild, moderate and severe based on scores of 0–7, 8–18 and > 18 respectively) and four age groups (< 50, 51–60, 61–70 and > 70 years). All patients with post-operatively urinary retention were catheterised per urethra.

Results: 8 (13.3%) males and 7 (8.8%) females were catheterised post-operatively. The average IPSS value in non-catheterised males and females were 8.9 and 9.5 respectively whereas in catheterised males and females were 21 and 19 respectively. 75% of catheterised males had an IPSS > 18. 85.7 % of catheterised females had an IPSS > 18. Statistical analysis showed significant association between high IPSS (> 18) and catheterisation risk in both males (chi square - p< 0.001, sensitivity- 0.75, specificity- 0.92, negative predictive value (NPV) - 0.96) and females (chi square - p< 0.001, sensitivity- 0.86, specificity- 0.90, NPV- 0.99). There was no significant relation between age and incidence of catheterisation.

Discussion: IPSS is a widely accepted, simple and easy to use tool to predict patients at risk of post-op catheterisation. It is a simple pre-assessment tool even in female patients. Patients with IPSS > 18 are most at risk of post-op retention.