Abstract
Introduction and Aims: The purpose of the present study was to review the early results and clinical performance of FDA approved large unipolar heads (36mm and greater) used with a metal-on-metal (MM) bearing.
Method: Fourteen stem type prostheses were implanted in 14 patients. There were eight primary THA, and six conversions of surface arthroplasties in which thin-walled (5mm) porous coated MM sockets were maintained. Mean age was 55.4 years (range 30–72 years). There were nine males and five females. Dislocation precautions were discontinued after capsular healing (six weeks). The initial etiology was OA in 78%.
Results: The median head size was 44mm (36–52) and socket size 54mm. Mean follow-up time was 29.1 months (range 12–81). UCLA hip scores improved for pain, walking, function, and activity from 4.8, 6.2, 6.1, and 4.8 pre-operatively to 9.3, 8.5, 7.5, and 5.4 postoperatively. Range of motion normalised. There were no complications.
Conclusion: This investigation shows excellent clinical results, and suggests that dislocation can be avoided by an anatomical THR with the use of large unipolar femoral heads and thin sockets with low wear bearings. The advantage of MM is the ability to manufacture thin shells with porous beads for fixation and preserve ace-tabular bone stock.
These abstracts were prepared by Editorial Secretary, George Sikorski. Correspondence should be addressed to Australian Orthopaedic Association, Ground Floor, The William Bland Centre, 229 Macquarie Street, Sydney, NSW 2000, Australia.
At least one of the authors is receiving or has received material benefits or support from a commercial source.
