The first 100 fully porous-coated femoral components in hip resurfacing

Uncemented fixation of implants to bone is a proven technology in traditional hip arthroplasty surgery. However, cement fixation is currently the standard method for the femoral component in hip resurfacing. The purpose of this study was to evaluate the performance of uncemented fixation of the femoral component in the first 100 fully porous-coated metal-on-metal hip resurfacing arthroplasties at a minimum follow-up of 2 years.

From March to October 2007, 100 consecutive uncemented metal-on-metal hip resurfacing arthroplasties in 95 patients (74 males and 21 females) were implanted by the same surgeon, using bone ingrowth technology for both femoral and acetabular components. The posterior minimally invasive approach was utilized in all cases. The primary diagnosis was osteoarthritis in 72% of cases, but other diagnoses were not excluded for the purposes of this study. The mean femoral component size was 51 ± 4 millimeters, and patients were not excluded for small component size.

The mean follow-up was 2.9 ± 0.2 years. The mean pre-operative Harris hip score was 57 ± 13 and improved to 96 ± 6 at the final follow-up visit. The mean UCLA activity score was 8 ± 2. There were two failures (2%): one femoral neck fracture at 2 months and one femoral component loosening at 12 months postoperatively.

The study demonstrated that fully porous-coated femoral resurfacing components have equivalent results to those reported for cemented femoral components at short-term follow-up. This suggests that the femoral head can reliably achieve bone ingrowth into a fully porous-coated femoral component. This encourages us to continue utilizing this bone ingrowth technique as an alternative to cement in this young and active patient group. Long-term follow-up will be needed.