Bone loss at hip resurfacing: A comparison with total hip arthroplasty.

Resurfacing arthroplasty of the hip has been advocated as a bone-conserving procedure although concerns have been raised as to whether this is truly the case. We therefore compared bone loss during hip resurfacing with bone loss at total hip arthroplasty under controlled conditions using dry pelvic and femoral Sawbones (DePuy, Leeds, UK). Ten sets of femoral and pelvic Sawbones were included in the study. Five sets were prepared for implantation of a hybrid total hip arthroplasty and five sets were prepared for insertion of hip resurfacing components. The Sawbones were weighed before and after preparation and the amount of dry bone loss was determined. During preparation of the femur for a resurfacing arthroplasty we resected 51.4% less Sawbone than for a total hip arthroplasty (mean 12.3g vs 25.3g, p<0.001). More bone (311.1%) was removed, however, during acetabular preparation for a resurfacing arthroplasty than for a total hip arthroplasty (mean 5.6g vs 1.8g, p<0.001). The total amount of Sawbone removed was 33.9% less for a resurfacing arthroplasty compared with a total hip arthroplasty (mean 17.9g vs 27.1g, p=0.001). We conclude that although reduced resection of femoral bone may be an advantage of hip resurfacing arthroplasty, the increased amount of bone that is removed from the acetabulum may prove problematic should patients require future revision surgery. (Hip International 2005; 15: 195-8).