1. INTRODUCTION
High tibial osteotomy (HTO) has been an effective surgical method for the treatment of moderate osteoarthritis of the medial compartment of the knee.1,2,3 Re-alignment of a varus deformity of the knee by HTO or total knee arthroplasty (TKA) inevitably changes the alignment of the ankle joint.4,5 However, the effects of these procedures on the ankle joint have not been well described.
Patients who suffer from degenerative osteoarthritis in both knee and ankle joints on the same limb are occasionally encountered in clinical practice. Osteoarthritis of the ankle is relatively rare compared to that of the knee.6 Moreover, patients with concurrent osteoarthritis and a varus deformity of both the knee and ankle in the same leg are extremely rare.2 Here, we reported two cases of patients with concurrent osteoarthritis of the knee and the ipsilateral ankle in whom an HTO was performed, resulting in significant clinical and radiographic improvement.