Aim: The aim of this study is to analyse the peri-operative complications of the Bimetric femoral hip prosthesis (Biomet UK Ltd) and to evaluate the osteo-conductive and osteo-inductive performance of HA coatings in this implant.

Materials and Methods: This is an ongoing randomised control study (retrieval) over a period of 4 years at William Harvey Hospital, Ashford, Kent. Three types of HA coatings were used – plasma sprayed HAC 60μm, bonemaster dense HAC 3μm, bonemaster graded HAC 7μm. Three retrieved implants were sent for histological examination at The Royal National Orthopaedic Hospital, Stanmore.

Results: Fifty Four patients with mean age of 77 years (66–89) were evaluated. There were 12 (22%) surgical complications- 9 (7.4%) periprosthetic fractures, 2 stems subsided, 1 stem cemented. There was 5.5 % (3/54) risk of revision in 4 years (p< 0.001). The histological photomicrograph with the three different coatings examined showed Bone master 3–7μm coating had excellent bony in growth (osteo-integration).

Conclusion: In our series there was 5.5% risk of revision rate. The periprosthetic fracture and early mortality rates are within national limits. Revision surgery is the most significant aspect and this should be our primary concern. Hydroxyapatite coated stems with newer technique coating promotes good osteo-integration.