This study reports the results of hybrid stem fixation in difficult revision hip arthroplasties where proximal femoral bone stock loss was severe.

Twenty-six revision arthroplasties (21 women and 5 men, aged from 58 to 86 years), were performed between 1998 and 2008. The indication for surgery was aseptic loosening. In all cases, stabilization of the stem presented problems because of severe proximal femoral bone stock loss (due to extensive periprosthetic osteolytic defects), or because of iatrogenic defects or surgical procedures (attempts to remove the stem and cement with fenestration or extended osteotomy). The average follow-up was 48 months (range 16 to 120).

Primary stability is necessary for the successful definite fixation of a cementless implant by bone. When this was not possible (because of proximal cortical insufficiency), we used a modular distally cemented long stem, bypassing the area of bone defect for at least 6–7 cm. Proximally bone defects were grafted and osteotomy was closed with cerclage wires.

Four stems (15%) had an asymptomatic subsidence (3 stems subsided less than 3–4 mm and 1 stem about 15mm). No stem was revised to date. Major complications did not occur. The mean Harris hip score improved from 32 points preoperatively to 82.3 points (at the most recent evaluation).

Hybrid fixation offers the advantage of initial and secure stability of the cemented stem on the short term, until stabilization of the entire implant by bone occurs. Thus early subsidence and loosening is avoided and on the long term benefits of the cementless fixation are attained. Our results support the method of hybrid fixation in patients with severe femoral bone loss (and consequently problematic stabilization), when primary stability is needed.