Subtrochanteric fracture after Garden screw fixation: a review of predisposing factors and management in nine cases.

Nine cases of subtrochanteric fracture are reviewed following 300 fixations of subcapital fractures with Garden screws. In six cases technical operative errors were considered to contribute to the fracture. It is stressed that adequate reduction and suitably placed crossed Garden screws are demanding requirements and that every attempt should be made to avoid making extra holes with guidewires. In two technically satisfactory cases the low position of the lower Garden screw-hole in the femur probably predisposed to the subtrochanteric fracture. A computerized two-dimensional finite analysis confirmed smaller magnitudes of stress at a more proximally positioned lower Garden screw, and in patients at risk, particularly those with a valgus femoral neck or valgus reduction, it is suggested that if this method of internal fixation is to be used, the screws should be crossed less obliquely, with the lower screw more proximally positioned in the femur.