Results of dynamic condylar screw for subtrochanteric fractures.

A consecutive series of 58 patients, treated with the dynamic condylar screw (DCS) for subtrochanteric fractures were retrospectively reviewed. The mechanism of injury was low-energy in 47 cases and high-energy in 11 cases. Five patients died before fracture healing. Ten out of 11 young patients, (nine with high-energy injuries), united primarily. In contrast, the primary union rate in the elderly was 74%. Implant failure was seen in 11 cases (20%). Restricted weight bearing status post-operatively was associated with significantly lower incidence of implant failure (P<0.05, chi(2)-test). The use of bone graft was not related to fracture union (P>0.5). After revision surgery the overall union rate in the elderly was 90%. Using the DCS, the results were good in the young patients with high-energy injuries. However, the implant failure rate is high in elderly patients who suffer low-energy fractures. The DCS should not be used if weight bearing cannot be minimized in this group.