Department of Orthopaedic Surgery, Yokohama City University School of Medicine, 3-9 Fukuura, Kanazawa, Yokohama, Kanagawa, 236-0004, Japan.
Department of Orthopaedic Surgery, Yokohama Hodogaya Central Hospital, Yokohama, Japan.
BMC Musculoskelet Disord. 2022 Aug 15;23(1):776. doi: 10.1186/s12891-022-05734-7.
We evaluated the relationship between the weight-bearing line (WBL) ratio and anatomical femorotibial angle (FTA) by simulated open wedge high tibial osteotomy (OWHTO). This study evaluated the correlation between the ''Fujisawa point'' and FTA, and identified factors which caused deviations between the two measurement methods. We hypothesized that the Fujisawa point corresponded with 170° of the FTA.
Preoperative antero-posterior full-length lower limb radiographs of 82 patients were obtained for the OWHTO to place the WBL ratio at a target of 62.5% of the width of the tibial plateau (Fujisawa point). The coronal alignment was measured pre- and post-planning. The patients were divided into two groups by the post-planning FTA: a correspondence group (168.5°≦FTA≦171.5°) and a non-correspondence group (FTA < 168.5°, 171.5° < FTA). The relationship between the Fujisawa point and the FTA was analyzed with multivariate regression analysis.
The post-planning FTA was 169.8 ± 1.1° and within 170 ± 1.5° in 69 cases (84.1%) when the WBL ratio was 62.5%. The neck shaft angle was 128.1 ± 5.2° in the correspondence group, and 122.3 ± 6.3° in the non-correspondence group. The multivariate linear regression analysis revealed that the neck shaft angle was the only factor that predicted the correspondence of the Fujisawa point with the FTA at 170° (p = 0.006, odd 1.28).
The post-planning FTA converged at 170° when the WBL ratio passed through the Fujisawa point and the neck shaft angle was the only predictor.
我们通过模拟开放式楔形胫骨高位截骨术（OWHTO）评估了负重线（WBL）比率与解剖股骨胫骨角（FTA）之间的关系。本研究评估了“Fujisawa 点”与 FTA 之间的相关性，并确定了两种测量方法之间产生偏差的因素。我们假设 Fujisawa 点对应于 FTA 的 170°。
对 82 例行 OWHTO 的患者进行术前前后全长下肢 X 线片，将 WBL 比率置于胫骨平台宽度的 62.5%（Fujisawa 点）的目标处。在规划前和规划后测量冠状面排列。根据规划后的 FTA 将患者分为两组：对应组（168.5°≦FTA≦171.5°）和不对应组（FTA<168.5°，171.5°<FTA）。使用多元回归分析分析 Fujisawa 点与 FTA 之间的关系。
当 WBL 比率为 62.5%时，规划后 FTA 为 169.8±1.1°，在 170±1.5°范围内的有 69 例（84.1%）。对应组的颈干角为 128.1±5.2°，不对应组为 122.3±6.3°。多元线性回归分析显示，颈干角是唯一预测 Fujisawa 点与 170° FTA 对应的因素（p=0.006，Odd 为 1.28）。
当 WBL 比率通过 Fujisawa 点时，规划后的 FTA 收敛于 170°，而颈干角是唯一的预测因素。
