[Ender nail with interlocking mechanism or dynamic hip screw in pertrochanteric fractures? A prospective study extending its limits].

In a prospective study on 148 patients with trochanteric fractures of the hip we compared the results of two implant-systems: the Ender-nailing modified by the dynamical interlocking method of Kempf and Bitar, and the dynamic hip screw (DHS) of the AO-ASIF. The Ender-method had the shorter operation time, earlier weight-bearing and less septic complications. Fracture consolidation was complete after three months in all cases. But in 8% reosteosynthesis because of hip joint perforations of nails was necessary. The method leads in less cases to anatomical reduction (85%), more often relevant varus (9%) and rotationary (14%) malpositions and functional deficits in hip (25%) and knee joints (9%), compared with the DHS. The DHS had less implant complications, reosteosynthesis was necessary in 4%. Technical failures were seldom. In 96% anatomical reduction could be achieved and the function of the hip was in 87% good to excellent. The Ender-nailing with dynamic interlocking is a system for internal fixation of trochanteric fractures in elder patients. The DHS-system has better functional results. Both systems need to be performed in a very careful, exact surgical procedure, to avoid complications.