Flail hip joint following periacetabular tumor resection of the pelvis using upper surface of the femoral neck as a saddle: A case report.

Reconstruction following periacetabular tumor resection of the pelvis is one of the most challenging issues in limb salvage surgery. An ideal procedure has still not been established. There are several reconstruction methods available, including arthrodesis, pseudoarthrosis, resection arthroplasty, prosthetic arthroplasty, saddle prosthesis, allograft and hip transposition. In our hospital, we have been using a flail hip joint procedure without reconstruction. Herein, we report good extremity function following a flail hip joint procedure which used the upper surface of the femoral neck as a saddle facing the remaining ilium. To the best of our knowledge, among the reported flail hip joint cases, this procedure has never been used. The patient is able to walk without any pain for several hundred meters with a shoe lift but without a cane, as observed at a 20-year follow-up. The authors consider that the flail hip joint using the upper surface of the femoral neck as a saddle is a simple and effective method.