Surgical management of a subtrochanteric fracture in a patient with 50-year longstanding intra-articular hip ankylosis and ischiofemoral synostosis: a case report

Background: We present a rare, previously unreported case of total hip arthroplasty (THA) implantation in a patient with an ankylosed hip and pelvic-femoral synostosis who sustained a subtrochanteric fracture. Case: A 70-year-old woman had previously undergone right-sided infectious coxitis treatment, leading to hip ankylosis and pelvic-femoral synostosis. The patient had experienced no hip joint movement from her 20s for over 50 years due to bone fusion at 2 levels. Walking was feasible with compensation, given the ankylosis at an “ideal position” of 15° of flexion, 10° of abduction, and neutral rotation. The patient sustained a subtrochanteric fracture at the age of 70. Given the ankylosis and pelvic-femoral synostosis in the proximal femur fragment, an ideal solution was sought for the surgical management of this case. Methods: Synostosis was resected, total hip replacement was performed using revision arthroplasty components, solving both the problem of the ankylosed hip and that of the subtrochanteric fracture. Results: The subtrochanteric fracture united, and sufficient motion was achieved after THA. Conclusions: THA led to adequate fracture healing, relief of chronic lumbosacral pain and significant improvements in function, proving to be a promising solution for challenging complex hip cases, offering significant improvements in quality of life when combined with careful surgical technique, thorough planning, and attentive postoperative care.