2023 ISAKOS Biennial Congress ePoster
Pre and Postoperative Changes in Alignment of the Ankle and Subtalar Joint in Patients Undergoing High Tibial Osteotomy for Knee Osteoarthritis
Yuki Nishimura, MD, Kashihara City, Nara Prefecture JAPAN
Munehiro Ogawa, MD, PhD, Kashihara, Nara JAPAN
Kensuke Okamura, MD, Kashihara, Nara JAPAN
Yusuke Inagaki, MD, PhD, Kashiba, Nara JAPAN
Yasuhito Tanaka, Prof., Kashihara, Nara JAPAN
Nara Medical University, Kashihara, Nara, JAPAN
FDA Status Not Applicable
Summary
High tibial osteotomy in patients with varus knee osteoarthritis reduces compensation for valgus alignment between the tibia and calcaneus
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Abstract
Background
High Tibial Osteotomy (HTO) is the main joint-preserving surgery for varus osteoarthritis of the knee, and although the HTO technique can alter the lower extremity alignment, the pre- and postoperative changes in the alignment of the ankle and subtalar joints in the coronal plane are not well known.
Objectives
In this study, we investigated the changes in coronal plane alignment of the ankle and subtalar joints in patients undergoing HTO before and after surgery using long x-rays of the lower extremities.
Study Design & Methods
Thirty two knees (22 males and 10 females, mean age 60.0 years) of 31 patients with varus knee osteoarthritis who underwent HTO were included in this study. All patients had frontal lower extremity long x-rays taken preoperatively and 1 month postoperatively. The midpoint of the tibial plateau was set as 0, the medial end as 100, and the lateral end as -100. A line from the center of the femoral head to the center of the tibial canal (Mikulicz line) and a line to the lowermost edge of the calcaneal contour were determined, respectively, to investigate the migration of the line at the level of the tibial plateau before and after surgery. We also determined the femoral tibial angle and tibial anterior surface angle, the angle between the tibial shaft and calcaneal shaft, and the tibial tilt angle before and after surgery to determine if there were any significant differences between the two.
Results
The Mikulicz line moved significantly outward from 46 to -22 at the tibial plateau and from 34.6 to -38.3 outward from the center of the femoral head to the lowest point of the calcaneal contour before and after surgery. FTA changed significantly from 178 to 171 degrees, but TAS did not change either to 89 degrees. The angle between the tibial shaft and calcaneal shaft decreased significantly from 10.8 to 9.6 degrees of valgus and the tibial tilt angle decreased significantly from 4.2 degrees to 0.3 degrees of varus.
Conclusions
HTO was found to alter not only femoral and tibial alignment, but also subtalar joint alignment.