The use of Gamma-irradiated proximal femoral allografts for bone stock reconstruction in complex revision hip arthroplasty

Abstract

We have followed a consecutive series of 49 revision hip arthroplasties, performed for severe femoral bone loss using Gamma-irradiated anatomic-specific proximal femoral allografts longer than five centimetres. The patients were followed for a median 10.2 years, with a five year minimum follow-up. The median preoperative Harris Hip Score (HHS) improved from 42 points to 77 points postoperatively. In four hips the femoral component was further revised for non-union of the allograft and aseptic failure. In one hip the allograft and the femoral component were removed because of infection. In one hip the allograft and the femoral component were re-revised for host step-cut fracture. Junctional-union was observed in 44/49 hips. By defining success as an increase of HHS by 20 points or more, a stable implant and no need for any subsequent re-operations related to the allograft and /or the implant, a success rate of 76% was observed. Kaplan-Meier survivorship analysis predicted 79% rate of survival at 10 years and 75% rate of survival at 17 years, with the need for further revision of the allograft and/or implant as the end point. Three hips underwent re-attachment of the greater trochanter for trochanteric escape. Asymptomatic non-union of the greater trochanter was noticed in another three hips. Moderate allograft resorption was observed in four hips. Two fractures of the host step-cut occurred. There were four dislocations. Good long-term results with the use of large anatomic-specific femoral allografts justify their continued use in cases of revision hip arthroplasty complicated with severe femoral bone loss.