Department of Orthopaedic Surgery, Graduate School of Medicine, Yokohama City University, 3-9 Fukuura, Kanazawa-ku, Yokohama, 236-0004, Japan.
Department of Orthopaedic Surgery, Yokohama City University Medical Center, Yokohama, Japan.
J Orthop Surg Res. 2024 Sep 28;19(1):598. doi: 10.1186/s13018-024-05096-x.
Postoperative change of the joint line convergence angle (JLCA) is known to be a factor affecting correction error in opening wedge high tibial osteotomy (OWHTO). The purpose of this study was to assess whether preoperative planning that considers change of the JLCA can achieve accurate correction in the standing position after OWHTO.
OWHTO was performed for 109 knees with osteoarthritis of the knee. The amount of angular correction was planned aiming to achieve mechanical valgus of 5° in 55 knees (conventional planning), and it was adjusted in 54 knees (adjusted planning) according to the preoperative JLCA as follows: not changed with JLCA ≤ 3°; decreased 1° with JLCA 4-6°; decreased 2° with JLCA 7-8°; and decreased 3° with JLCA ≥ 9°. The hip-knee-ankle (HKA) angle, JLCA, and medial proximal tibial angle (MPTA) were measured on standing long-leg radiographs. Correction error ≤ 2º was defined as the acceptable range, and correction error > 2º was defined as an outlier.
The conventional planning group had a significantly greater postoperative HKA angle than the adjusted planning group (6.1º and 4.9º, respectively). The mean JLCA decreased from 4.8º to 2.6º in the conventional planning group and from 4.6º to 2.7º in the adjusted planning group. The conventional planning group had significantly greater postoperative MPTA than the adjusted planning group (96.2º and 94.7º, respectively). The rate of outliers with correction error > 2º was significantly lower in the adjusted planning group (9%) than in the conventional planning group (24%). The rate of the MPTA > 95º was significantly lower in the adjusted planning group (30%) than in the conventional planning group (69%).
This study demonstrated that preoperative planning with adjustment of the correction angle according to the preoperative JLCA improved correction accuracy in the standing position after OWHTO.
关节线会聚角（JLCA）的术后变化已知是影响开放式楔形胫骨高位截骨术（OWHTO）开口矫正误差的因素。本研究旨在评估是否可以通过考虑 JLCA 变化的术前规划来实现 OWHTO 后站立位的准确矫正。
对 109 例膝关节骨关节炎行 OWHTO。为 55 例膝关节（常规规划）计划了角度矫正量，以实现 5°的机械外翻，并根据术前 JLCA 调整了 54 例膝关节（调整规划），如下所示：JLCA≤3°时不变；JLCA 为 4-6°时减少 1°；JLCA 为 7-8°时减少 2°；JLCA≥9°时减少 3°。在站立位长腿 X 线片上测量髋膝踝（HKA）角、JLCA 和胫骨近端内侧角（MPTA）。将矫正误差≤2º定义为可接受范围，将矫正误差>2º定义为异常值。
常规规划组术后 HKA 角明显大于调整规划组（分别为 6.1º和 4.9º）。常规规划组 JLCA 从 4.8º降至 2.6º，调整规划组从 4.6º降至 2.7º。常规规划组术后 MPTA 明显大于调整规划组（分别为 96.2º和 94.7º）。调整规划组矫正误差>2º的异常值率（9%）明显低于常规规划组（24%）。调整规划组 MPTA>95º的发生率（30%）明显低于常规规划组（69%）。
本研究表明，根据术前 JLCA 调整矫正角度的术前规划可提高 OWHTO 后站立位的矫正准确性。
