Total Knee Arthroplasty in Patients With Prior Ipsilateral Hip Fusion: A Surgical Technique

Background: In patients with severe osteoarthritis of the knee with prior ipsilateral hip fusion who require total knee arthroplasty (TKA), a controversial issue is whether to first convert the hip fusion to a total hip arthroplasty (THA) or to perform TKA without reconstruction of the hip. Also, immobility of the ipsilateral, fused hip adds significant technical challenge because the usual positioning of the leg requires modification in order to gain access needed for the TKA. Technique: In such cases, we position the patient with the knee suspended, similar to how we perform knee arthroscopy. In our experience, the ipsilateral knee has significant deformity and is best addressed with a constrained, hinged TKA. Results: In 3 patients with severe knee osteoarthritis with prior ipsilateral hip fusion—a 72-year-old man and a 79-year-old woman with hip arthrodesis due to posttraumatic arthritis and an 81-year-old woman with hip arthrodesis due to congenital dislocation of the hip—rotating-hinge knee prostheses were implanted due to severe knee instability. All 3 patients had satisfactory results, without complications, after follow-up of 1 to 5 years. Conclusions: We obtained satisfactory results in the short and medium term without previously converting the hip arthrodesis to THA by positioning patients with the knee suspended, in a way similar to when knee arthroscopy is performed, and implanting rotating hinge TKAs due to severe preoperative knee instability.