Single-stage ipsilateral total hip and total knee arthroplasty for developmental dysplasia-related hip osteoarthritis and ipsilateral knee osteoarthritis: a case report

Introduction and importance: Developmental dysplasia of the hip (DDH) is an important cause of secondary hip osteoarthritis and can alter the mechanical environment of the ipsilateral lower limb. Same-session ipsilateral total hip arthroplasty (THA) and total knee arthroplasty (TKA) remain uncommon, although cohort studies and case reports have described the use of this approach in selected patients. Case presentation: A 60-year-old woman with neglected right DDH presented with approximately 10 years of progressive hip pain and 7 years of ipsilateral knee pain, with marked worsening during the preceding 8 months despite nonoperative management. She had an antalgic gait, an approximately 3-cm clinical leg-length discrepancy, severe hip stiffness, a valgus knee deformity of approximately 15 degrees, knee range of motion from 0 degrees to 90 degrees actively and from 0 degrees to 110 degrees passively, and a positive anterior drawer test. Radiographs showed a dislocated, arthritic, dysplastic hip with femoral-head collapse and pseudoacetabulum formation, together with valgus knee osteoarthritis, predominantly involving the lateral and patellofemoral compartments. Clinical discussion: The patient underwent single-stage ipsilateral THA followed by TKA. The hip was reconstructed at the true acetabular level using a cementless cup, augmented with an autologous femoral-head bone graft secured by two cancellous screws, and a cementless femoral stem. A cemented TKA was then performed without changing the supine position. Mobilization began on postoperative day 1, and the patient was discharged on postoperative day 3. Immediate postoperative radiographs demonstrated satisfactory component positions, acetabular graft fixation, and improved coronal knee alignment. The available record did not include prospectively collected validated outcome scores or long-term follow-up. Conclusion: Single-stage ipsilateral THA and TKA may be considered for carefully selected patients with severe symptomatic disease in both joints when the anticipated biomechanical and rehabilitation advantages justify the increased perioperative burden. This report supports the early technical feasibility but does not establish the comparative safety or long-term superiority over staged surgery.