[Surgical technic in femur shaft fenestration within the scope of revision operations following hip joint total endoprostheses].

In revision arthroplasty the loss of stability secondary to fenestration of the proximal femur reduces the loading capacity of the limb and increases the risk of postoperative fractures. Trying to improve the fenestration technique we tested the usual fenestration procedure experimentally. Besides pure axial load we investigated the torsional forces of the proximal femur in the bended hip position. We recorded the deformation under increasing load and analysed the fracture pattern. The results shows an unwarantable loss of stability in lateral or complete ventral fenestration procedures. Ventral fenestration procedures with smooth edges and intact proximal bony ring having additional prosthesis stem support presented the best mechanical results. According to the tolerated load it is possible to give guide-lines for the postoperative treatment in the cemented and cementless arthroplasty of the hip joint.