Department of Orthopaedics, Xinqiao Hospital, Army Medical University (Third Military Medical University), Chongqing, China.
Orthop Surg. 2023 Apr;15(4):953-960. doi: 10.1111/os.13647. Epub 2023 Jan 31.
Mismatch between the femoral component and the resected surface is related to the postoperative clinical outcome. This study aimed to measure the morphometric features of the distal femoral resected surfaces in patients with osteoarthritis in southwestern China and to compare the measured morphometric data with six commonly used total knee arthroplasty (TKA) femoral components in China.
The computer tomography (CT) images of a total of 406 knees from 203 osteoarthritis patients who underwent TKA from January 2018 to December 2021 were imported into Mimics 21.0 software to reconstruct the three-dimensional (3D) model of the femur. Morphometric data of the distal femoral resected surfaces were measured after the completion of simulated bone resection in the software. The data included the medial-lateral (ML) dimension, anterior-posterior (AP) dimension, and the aspect ratio (AR) (AR = ML/AP), which were compared between genders with independent sample t-tests. In addition, we plotted the scatter diagram of those morphometric data in Origin software, and the linear fits of ML versus AP and AR versus AP were performed and compared for the six femoral components commonly used in enrolled patients in China.
The mean ML dimension, the mean AP dimension, and the mean AR value measured for Chinese knees were 66.62 ± 4.57 mm, 58.10 ± 3.74 mm, and 1.15 ± 0.06 respectively. All dimensions were significantly larger in males than in females, including the calculated values for AR (P < 0.05). The fitted lines for males showed that the ML dimensions tended to be wider compared to femoral components of a given AP dimension. Females tended to have wider ML dimensions compared to small femoral components and, on the other hand, narrower ML dimensions compared to large femoral components.
The femoral component of the current commonly used TKA prosthesis in China may not be perfectly matched to the distal femoral resected surface of patients in southwestern China. Male patients tended to underhang in all dimensions of the ML dimension. Female patients with shorter AP lengths are more likely to experience underhang, whereas those with longer AP lengths are more likely to develop overhangs. Therefore, we recommend multiple ML width options for a given AP length to more appropriately match the Chinese femoral anatomy.
股骨部件与切除表面之间的不匹配与术后临床结果有关。本研究旨在测量中国西南部骨关节炎患者股骨远端切除表面的形态特征，并将测量的形态数据与中国六种常用的全膝关节置换术（TKA）股骨部件进行比较。
从 2018 年 1 月至 2021 年 12 月期间接受 TKA 的 203 名骨关节炎患者的共 406 个膝关节的计算机断层扫描（CT）图像被导入 Mimics 21.0 软件中，以重建股骨的三维（3D）模型。在软件中完成模拟骨切除后，测量股骨远端切除表面的形态数据。数据包括内侧-外侧（ML）尺寸、前-后（AP）尺寸和纵横比（AR）（AR=ML/AP），并通过独立样本 t 检验比较性别间的差异。此外，我们在 Origin 软件中绘制了这些形态数据的散点图，并对中国患者中常用的六种股骨部件进行了 ML 与 AP 以及 AR 与 AP 的线性拟合比较。
中国膝关节的平均 ML 尺寸、平均 AP 尺寸和平均 AR 值分别为 66.62±4.57mm、58.10±3.74mm 和 1.15±0.06。男性的所有尺寸均显著大于女性，包括计算的 AR 值（P<0.05）。男性拟合线表明，与给定 AP 尺寸的股骨部件相比，ML 尺寸趋于更宽。女性的 ML 尺寸与小的股骨部件相比更宽，而与大的股骨部件相比更窄。
中国当前常用的 TKA 假体股骨部件可能与中国西南部患者的股骨远端切除表面不完全匹配。男性患者在 ML 尺寸的所有尺寸上都倾向于悬垂。AP 长度较短的女性患者更有可能出现悬垂，而 AP 长度较长的女性患者更有可能出现过伸。因此，我们建议为给定的 AP 长度提供多个 ML 宽度选项，以更适当地匹配中国股骨解剖结构。
