THA for Hip Ankylosed Before Skeletal Maturity with Complex Femoral Deformity and Subtrochanteric Nonunion

Case: Total hip arthroplasty (THA) in hips ankylosed and deformed from childhood infection is technically demanding because of distorted anatomy, poor bone quality, and abductor deficiency. A 48-year-old woman with fused hip, subtrochanteric nonunion, and proximal femoral hypoplasia underwent conversion THA through a posterior approach. A dual mobility acetabular cup and long-stem uncemented femoral component were used to reduce the instability risk and achieve fixation. Her postoperative course was uneventful, though rehabilitation was prolonged due to abductor atrophy. Conclusion: This case highlights the importance of surgical planning, implant selection, and tailored rehabilitation in complex hip reconstructions.