2.1. Case 1
A 48-year-old female patient who complained of serious pain in the right knee and ipsilateral ankle for about three years presented to our clinic in January 2019. She had no systemic musculoskeletal disease or other medical history. She was 150.0 cm in height and 57.0 kg in weight, with a body mass index of 25.3 kg/m2. Pain in both the knee and ankle joints began three years ago due to a moderate varus deformity and osteoarthritis of the double joints. Physical examination showed that the right knee could actively flex to 120° and had a prominent hyperextension of about 5°. The Hospital for Special Surgery (HSS) score of the right knee was 65. In addition, the right ankle was swollen and showed abnormal plantar flexion and was markedly varus. The osteoarthritic ankle stage was Takakura’s classification stage 3.7 Hip and pelvis movements were symmetrical, full, and pain-free. The results of the spine examination were normal with no neurological abnormalities.
Kellgren-Lawrence (K-L) grade II~III osteoarthritic change of the right knee was documented. The weight-bearing X-ray showed the varus deformity, and the hip-knee-ankle (HKA) angle was 8.2°. Her ankle was noted to have 16.4° of varus talar tilt (TT) and 6.1° of tibial inclination (TI) (Fig. 1).
We considered that her ankle symptoms could be attributed to the varus alignment of the left knee. Through a medial approach above the pes anserinus, an opening wedge HTO was performed. Intraoperatively, the medial osteotomy wedge was opened to 9° and the desired correction was achieved. The patient recovered without any complications and was advised to perform non-weight-bearing mobilization with a walker during rehabilitation.
The patient was satisfied with the outcome of her surgery, reporting a marked reduction in pain and improved stability of both knee and ankle joints six weeks postoperatively. Three months later, there was no pain in her left knee, and she could walk unaided. Her active range of motion was 0 to 135°. The HSS score of the right knee was 85 three months after surgery and she volunteered a subjective improvement in ankle pain of 95%.
The postoperative weight-bearing X-ray showed favorable limb alignment on the coronal view. The standing HKA angle improved from a preoperative value of 8.2° to 0° at follow-up. The TT was corrected from 16.4° to 8.2° and the TI from 6.1° to 0.7° (Fig. 2).