Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.
Joint Reconstruction Center, Department of Orthopaedic Surgery, Yonsei Sarang Hospital, 10 Hyoryeong-ro, Seocho-gu, Seoul, 06698, Republic of Korea.
J Orthop Surg Res. 2020 Dec 11;15(1):603. doi: 10.1186/s13018-020-02146-y.
Although several reference axes have been established for determining femoral rotational alignment during total knee arthroplasty (TKA), the most accurate axis is undetermined. This study determines the relationship between the posterior cortical axis (PCA) and the trochlear anterior line (TAL) of the femur in relation to the epicondylar axis.
A total of 341 patients who underwent TKA for osteoarthritis were enrolled. Patients who had undergone previous bony surgery or replacement that might have changed the femoral geometry were excluded. Finally, 336 patients (200 females and 136 males) were included in the study. The angles between the transepicondylar axis (TEA) and TAL and TEA and the femoral PCA (FPCA) were evaluated. We also assessed whether there was any significant differences in variance and gender in these two angles. Student's t tests were used to determine the significance of coronal alignment and any gender-based differences. The variances between the TAL/TEA and FPCA/TEA angles were compared using F tests.
The FPCA was externally rotated by 2.6° ± 3.6°, and the trochlear anterior line was internally rotated by 5.2° ± 5.5°, relative to the TEA. Gender-based differences were observed in the comparisons between anatomical references and TEA.
The FPCA is a more conservative landmark than the TAL for intraoperative or postoperative approximation of the TEA. When conventional reference axes, such as the posterior condylar axis and the anteroposterior axis, are inaccurate, surgeons can refer to this alternative reference. These findings demonstrate that the FPCA may be useful for determining the rotational alignment of the femoral component before and during TKA.
尽管已经建立了几种参考轴来确定全膝关节置换术（TKA）中股骨的旋转对线，但最准确的轴仍未确定。本研究旨在确定股骨后皮质轴（PCA）与滑车前线（TAL）相对于髁间轴（TEA）之间的关系。
共纳入 341 例因骨关节炎行 TKA 的患者。排除了既往行可能改变股骨几何形状的骨手术或置换术的患者。最终，共有 336 例患者（200 例女性和 136 例男性）纳入本研究。评估了 TEA 与 TAL 和 TEA 与股骨 PCA（FPCA）之间的角度。我们还评估了这两个角度在方差和性别方面是否存在显著差异。使用 Student's t 检验确定冠状对线的显著性和任何基于性别的差异。使用 F 检验比较 TAL/TEA 和 FPCA/TEA 角度之间的方差。
FPCA 相对于 TEA 外旋 2.6°±3.6°，滑车前线内旋 5.2°±5.5°。在解剖参考与 TEA 之间的比较中观察到性别差异。
与 TAL 相比，FPCA 是术中或术后 TEA 接近的更保守的标志。当常规参考轴（如后髁轴和前后轴）不准确时，外科医生可以参考这个替代参考。这些发现表明，在 TKA 之前和期间，FPCA 可能有助于确定股骨组件的旋转对线。
