Managing Hip Arthritis in an Above-Knee Amputee: A Case Report of Total Hip Arthroplasty with Surgical Technique and Rehabilitation Considerations.

Introduction: With improved survival rates and functional outcomes, amputees are increasingly presenting with degenerative hip pathology requiring total hip arthroplasty (THA). However, THA in patients with ipsilateral lower limb amputation poses unique anatomical, biomechanical and technical challenges, and current surgical training often lacks specific technical insights for these complex cases. The literature remains limited, with few reports detailing technical strategies and rehabilitative measures in this patient population. This report aims to contribute to the existing knowledge by highlighting key pre-operative, operative and rehabilitative considerations in THA following transfemoral amputation. Case Report: A male in his early 30s, with left above-knee amputation following trauma 3 years prior, developed progressive left hip pain impairing prosthetic ambulation. Radiographs revealed advanced osteoarthritis with femoral head collapse and retained internal fixation hardware. Pre-operative assessment included full-length femur imaging and bone density evaluation, confirming adequate bone stock. An uncemented total hip replacement was performed via a modified lateral approach. Intraoperative control of the femoral stump was achieved with a Steinmann pin inserted in the distal femur, facilitating dislocation and stem positioning without compromising fixation. Post-operatively, rehabilitation emphasized strengthening hip flexors, extensors, abductors, and adductors, with weight-bearing deferred until soft tissue healing permitted prosthetic fitting. By 3 months, the patient resumed independent ambulation with the prosthesis. Follow-up imaging at 6 months showed stable implant integration. The Harris Hip Score improved from 30 pre-operatively to 70 post-operatively. Conclusion: THA in above-knee amputees requires meticulous preoperative planning, including detailed imaging and bone quality evaluation, alongside tailored intraoperative techniques, such as traction pin use for stump control. Implant fixation strategy must consider residual femur morphology, and rehabilitation should be customized to overcome specific muscular deficits. With comprehensive management, favorable functional outcomes and prosthetic gait restoration can be achieved in this challenging patient population.