Changes in Alignment of Ipsilateral Knee on Computed Tomography after Total Hip Arthroplasty for Developmental Dysplasia of the Hip.

Total hip arthroplasty for DDH could induce changes in alignment of ipsilateral patellofemoral and tibiofemoral joints, with increases in patellar tilt and displacement, and increases in external rotation of the tibia. These secondary alterations still existed at medium-term follow-up after surgery, which should be considered during THA for patients with DDH. Extended follow-up is necessary to evaluate long-term changes in the knee joint.