Creation of an Above-the-Knee Amputation Stump After Hip Disarticulation for Severe Periprosthetic Infection and Fracture

Abstract

R ecurrent infection at the site of a total joint replacement secondary to a highly resistant organism in combination with a periprosthetic fracture presents a treatment challenge. To salvage this situation, a hip disarticulation or a type-B-IIIb rotationplasty, as described by Winkelmann, are the only viable surgical techniques reported in the literature of which we are aware1,2. The purpose of our report is to present an alternative surgical technique for creating an above-the-knee stump with use of a modular proximal femoral replacement with a bipolar head after hip disarticulation. The procedure consists of two stages. Following implant removal and debridement, an antibiotic-impregnated polymethylmethacrylate spacer is implanted. After the proximal part of the femur is removed, the greater trochanter is fixed to the spacer to prevent shortening of the gluteal muscles. During this first stage, either an immediate hip disarticulation with reconstruction of an above-the-knee stump is performed (Case 1) or the extremity is preserved (Case 2). The former should be considered for a patient with a severe periprosthetic fracture, severe vascular compromise distally, or inadequate soft-tissue coverage. Following treatment with intravenous antibiotics, the patient is managed with reconstruction of an above-the-knee stump with use of a modular proximal femoral replacement implant (MUTARS; Implantcast, Buxtehude, Germany) and a bipolar head. In general, the original lateral incision is preferred and distally a fish-mouth skin incision is used for the amputation. The end of the reconstruction is covered with an anterior flap that is large enough so that the scar lies posteriorly. However, a reconstruction with use of a medial or an anterior flap is possible if the lateral soft tissues are severely scarred3. Depending on the quality of the soft-tissue coverage, every effort should be made to preserve a stump length of at least 25 cm, …