This study was designed to assess the necessity of additional supporting fixation to the traditional internal fixation for unstable intertrochanteric fractures of femur.

Seventy two cases of unstable intertrochanteric fractures (modified Boyd-Anderson type III, IV) in the elderly were reviewed, which were internally fixed with Dynamic Hip Screw. 48 cases were treated with Dynamic Hip Screw only(Group I) and 24 cases with Dynamic Hip Screw and additional trochanteric supporting plate(Group II). In 13 cases with weak femoral cortx, we added wiring to the side plate. We measured neck-shaft angle, degrees of displacement of greater trochanteric fragment, slippage of hip screw on plain radiographs.

Varus change in neck-shaft angle, displacement of greater trochanteric fragment and slippage of hip screw revealed 7.3°, 5.4 mm, and 10.7 mm respectively in group I, while 2.1°, 0.1 mm and 3.8 mm respectively in group II. There were no pullout of cortical screws.

Internal fixation with additional trochanteric supporting plate to the conventional Dynamic Hip Screw was effective in unstable intertrochanteric fractures of the femur in the elderly. Added wiring to the side plate was also helpful in weak femoral cortex.