Abstract
Background: High volumetric wear of polyethylene was the main factor in periprosthetic bone resorption and the failure of historic metal or ceramic on polyethylene hip resurfacing prosthesis. Metal on metal devices reduce the wear substantially and may solve this problem. The present study describes the clinical and radiographic results of our first 300 hips treated with the Birmingham Hip Resurfacing (BHR, Midland Medical Technologies, U.K.).
Methods: Between September 1998 and May 2003, 300 BHR were implanted in 262 patients. The patients had an average age of 49 years, 56% were men, 58% had a diagnosis of a CDH, 19% of osteoarthritis and 11% of avascular necrosis. Clinical and radiographic follow-up was performed at three months postoperatively and yearly thereafter.
Results: The average duration of follow-up was 2.4 years (1 to 5 years). We achieved a follow-up rate of 97%. Mean Harris Hip Score increased from 51 points pre-operatively to 91–92 points after one to five years, Total range of motion increased from 136 to 220. 6 prostheses had to be revised due to malposition (2), infection (2), neck fracture (1) and inguinal pain (1). Acetabular radiolucencies were observed in 3% in one zone, femoral radiolucencies in 5% in one to three zones around the stem. No patient showed radiolucency lines in all zones or migration.
Conclusions: In our opinion the cementless press fit cup, the low wear metal-on-metal bearing and the conservative implantation technique of the BHR at least fundamentally improves the known disadvantages of the historic Resurfacings. Our preliminary experience is encouraging, but has to be proofed in long-term observations.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
