Department of Orthopaedic Surgery, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa-Ku, Yokohama, 236-0004, Japan.
BMC Musculoskelet Disord. 2022 Dec 23;23(1):1121. doi: 10.1186/s12891-022-06101-2.
Double level osteotomy (DLO) has been introduced to prevent increased postoperative joint line obliquity. However, although DLO is planned, knees with postoperative medial proximal tibial angle (MPTA) > 95° in preoperative surgical planning are present. This retrospective study aimed to evaluate risk factors for an MPTA > 95° in preoperative surgical planning for DLO in patients with varus knee osteoarthritis (OA).
A total of 168 knees that underwent osteotomies around the knee for varus knee OA were enrolled. The hip-knee-ankle angle (HKA), weight-bearing line (WBL) ratio, mechanical lateral distal femoral angle (mLDFA), joint line convergence angle (JLCA) and mechanical medial proximal tibial angle (mMPTA) were measured on preoperative radiographs. The postoperative WBL ratio was planned to be 62.5%. When the postoperative mMPTA was more than 95° in isolated high tibial osteotomy (HTO), (DLO) was planned so that the postoperative mLDFA was 85°, and residual deformity was corrected by HTO. Knees with postoperative mMPTA ≤ 95° and > 95° were classified into the correctable group and uncorrectable group, respectively.
DLO was required in 101 knees (60.1%). Among them, 41 knees (40.6%) were classified into the uncorrectable group. Binomial logistic regression analysis showed that preoperative JLCA and mMPTA were independent predictors in the uncorrectable group.
Even with DLO, postoperative mMPTA was more than 95° in approximately 40% of cases. Preoperative increased JLCA and decreased mMPTA were risk factors for a postoperative mMPTA of > 95° after DLO.
双平面截骨术（DLO）已被引入以防止术后关节线倾斜增加。然而，尽管计划进行 DLO，但在术前手术计划中仍存在术后内侧近端胫骨角（MPTA）>95°的膝关节。本回顾性研究旨在评估在膝关节内侧骨关节炎（OA）患者中，DLO 术前手术计划中 MPTA>95°的危险因素。
共纳入 168 例膝关节周围行截骨术治疗膝内翻 OA 的膝关节。在术前 X 线片上测量髋膝踝角（HKA）、负重线（WBL）比值、机械外侧股骨远端角（mLDFA）、关节线会聚角（JLCA）和机械内侧近端胫骨角（mMPTA）。术后 WBL 比值计划为 62.5%。当单独行高胫骨截骨术（HTO）时，术后 mMPTA 大于 95°，（DLO）计划使术后 mLDFA 为 85°，并通过 HTO 矫正残余畸形。术后 mMPTA≤95°和>95°的膝关节分别分为可矫正组和不可矫正组。
需要 DLO 的膝关节 101 例（60.1%）。其中，41 例（40.6%）被归类为不可矫正组。二项逻辑回归分析显示，术前 JLCA 和 mMPTA 是不可矫正组的独立预测因子。
即使进行了 DLO，术后 mMPTA 仍大于 95°的情况约占 40%。术前 JLCA 增加和 mMPTA 减少是 DLO 后术后 mMPTA>95°的危险因素。
