In the subtrochanteric region of the femur high tensile forces are active in the lateral cortex and even higher compressive forces in the medial cortex. Subtrochanteric fractures are often comminuted. The implant of choice for osteosynthesis of subtrochanteric femoral fractures is the condylar plate. Usually the various fragments are dissected intraoperatively and the medial cortex is reconstructed anatomically for improved abutment. This devitalizing of fragments leads to disturbed healing, so that failures are frequent despite cancellous bone grafting. The osteosynthesis technique introduced by Mast and Ganz of indirect reduction by distractor without dissection of the fragments and the medial cortex allowed the complication rate to be reduced to 0%. We have modified this technique in that we performed closed reduction on the traction table rather than using the distractor to achieve axial and rotational alignment, after which the fracture is stabilized with dynamic condylar screw (DCS) under image intensifier control. The proximal femur is dissected only laterally and only in so far as in necessary to place the DCS. We never use cancellous bone grafting. From 1988 to 1990 this technique was used in 12 patients. All fractures had healed uneventfully after 4 months. bearing line lies outside the bone here, so that high tensile forces are generated in the lateral cortex and even higher compressive forces in the medial cortex [9,11,15,20].
Subtrochanteric fractures of the femur are usually comminuted, sometimes oblique or spiral fractures with a comminuted zone medially; in rare cases they are transverse fractures. The comminution zone usually present medially and the high bending forces acting on the proximal femur render osteosynthesis difficult. Despite the numerous implants that have been proposed for stabilizing these fractures, the failure rate is high at 10%-40% [1, 2. 5, 6, 14. 17. 19, 21, 22. 24]. Mast and Ganz were able to reduce the rate of complications to 0% with the technique of indirect reduction with a distractor [8]. By this technique the fracture is stabilized with a condylar plate. This technique of osteosynthesis is very demanding, We have adopted the basic idea of this technique (indirect reduction and fixation of the fracture without visualization of the fracture lines) and modified it. On the extension table closed axial and rotational alignment of the fi'acture is achieved. The fracture is fixed with a dynamic condylar screw (DCS) under image intensiver control without touching the comminuted zone.