[Clinical evaluation of PFNA® and relationship between the tip-apex distance and mechanical failure]

The incidence of trochanteric fractures is increasing in Europe, and the economic impact and mortality is high. The aim of the study was to evaluate the PFNA® (proximal femoral nail antirotation) with respect to its clinical use and mechanical complications.All patients with a trochanteric fracture who had been treated with a PFNA® between 12/2004 and 12/2007 were identified and analysed regarding complications and radiological findings. The study included 195 patients; 61.2% of the patients were classified as Singh I und II. The mean duration of surgery was 57 min. In ten cases (5.1%) the blade migrated, four cases (2.1%) showed blade cut out and in one case the nail broke (0.5%). The mean TAD was 26.7 mm, in cases of cut out 41.3 mm and in blade migrations 38.6 mm. No failure could be documented when the TAD was less then 30 mm. There is a strong relationship between increasing TAD and mechanical failure (P<0.001); 84.6% of the patients have been followed up, and 30.2% died in the follow-up period.The PFNA® is an easy-to-use implant for the treatment of stable and instable proximal femur fractures. Mechanical failure depends on the TAD.