Change in limb length after high tibial osteotomy using computer-assisted surgery: a comparative study of closed- and open-wedge osteotomies.

ABSTRACT

PURPOSE: Limb length changes were evaluated after closed- and open-wedge high tibial osteotomies (HTOs) using computer-assisted surgery. METHODS: A total of 78 closed- and 30 open-wedge HTOs were performed. The changes in limb length were evaluated on a navigation system and radiographs. The correction angle was defined as the difference between the pre and postoperative mechanical axis on the navigation system. The change in limb length with respect to the correction angle was analyzed. RESULTS: Following the closed-wedge HTOs, the mean changes in limb length based on the navigation system and radiographs were -1.3 ± 1.9 and -1.3 ± 10.7 mm, respectively, versus 6.2 ± 2.6 and 7.8 ± 2.9 mm after the open-wedge HTOs. The mean correction angle was 11.6 ± 3.2° for closed-wedge HTOs and 11.5 ± 1.9° for open-wedge HTOs. The correction angle did not affect the change in limb length after closed-wedge HTO, while the larger the correction angle required, the greater the increase in limb length after open-wedge HTO. CONCLUSIONS: The change in limb length was negligible after closed-wedge HTO, while the limb length was increased slightly after open-wedge HTO. The possibility of limb lengthening must be considered carefully when determining whom to perform open-wedge HTO on, especially when a large correction angle is required. LEVEL OF EVIDENCE III.