O2054 DISTAL CEMENT RESTRICTION IN TOTAL HIP REPLACEMENT: A RANDOMISED PROSPECTIVE COMPARISON BETWEEN BONE AND PLASTIC

Abstract

Aims: The aim of this study was to compare the efþcacy of plastic and bone block cement restrictor as a medullary plug in total hip replacement. Methods: In this pro- spective study all patients undergoing a primary charnley total hip replacement were randomised to receive either a Hardinge cement restrictor or a Bone block. The medullary plug was inserted to a constant distance. Postoperative standardised radiographs were assessed. The length of the distal mantle was compared between the two groups. Results: 119 hips with a bone block (BB) and 85 hips with a Hardinge plastic cement restrictor (CR) were analysed over a period of 4 years. Analysis of the data by the application of the Two-sample t Ð test, ANOVA and Mann Ð Whitney test revealed a statistically signiþcant difference between the two groups (p < 0.0001). 95% CI limits for BB (a) & CR (a)(t Ð test) = (−12.9, −6.6); 95% CI (Mann-Whitney test) = (−13.002, −8.001). Results show that the plastic cement restrictor migrates distally to a greater degree than the bone plug. Conclusion: Interdigitation of cement into the cancellous endosteal bed depends on intramedullary pressure. The depth of the cement mantle is a measure of the intramedullary pressure and the function of the cement restrictor. We conclude that the bone plug is better in primary hip replacements.