Hu Wan-Kun, Chen Da-Wei, Li Bing, Yang Yun-Feng, Yu Guang-Rong
1 Department of Orthopaedics, Shanghai Pudong Hospital, Fudan University, Shanghai, China.
2 Department of Orthopaedic Trauma, East Hospital, Tongji University School of Medicine, Shanghai, China.
J Orthop Surg (Hong Kong). 2019 May-Aug;27(2):2309499019842879. doi: 10.1177/2309499019842879.
The distal tibiofibular syndesmosis is an important structure for ankle stability. The objective of this study was to evaluate the motion of the syndesmosis under different loading patterns and determine the characteristics of the syndesmotic motion.
Six fresh cadaveric lower extremity specimens with the knee reserved were tested in this study. The skin and muscles were removed with all ligaments around the syndesmosis and knee and ankle joint intact. An axial load of 600 N was applied to the specimens with the ankle joint in 10° dorsiflexion, neutral position, and 15° plantar flexion using a universal material testing machine. Then, with the ankle joint positioned neutrally, a combination of 600-N axial and 5-Nm torsional external rotation loading was applied to the specimens. The medial-lateral and anterior-posterior displacement and rotation of the distal fibula relative to the distal tibia were measured.
Under the axial loading, the distal fibula tended to move medially and anteriorly and rotate internally with the ankle positioned from the neutral position to 15° plantar flexion. Meanwhile, when the ankle was positioned from the neutral position to 10° dorsiflexion, the distal fibula tended to move laterally and posteriorly and rotate externally. Under the combined loading, with respect to the isolated axial loading, the distal fibula tended to move medially and posteriorly, and rotate externally relative to the distal tibia.
Micro motion existed in the syndesmosis. The relative motion of the syndesmosis was correlated to the ankle position and loading patterns.
胫腓下联合是维持踝关节稳定性的重要结构。本研究旨在评估不同负荷模式下胫腓下联合的运动情况，并确定其运动特征。
本研究对6具保留膝关节的新鲜尸体下肢标本进行测试。去除皮肤和肌肉，保留胫腓下联合及膝关节和踝关节周围的所有韧带。使用万能材料试验机对标本施加600 N的轴向负荷，踝关节分别处于10°背屈、中立位和15°跖屈。然后，将踝关节置于中立位，对标本施加600 N轴向负荷与5 N·m扭转外旋负荷的联合作用。测量腓骨远端相对于胫骨远端的内外侧和前后位移及旋转情况。
在轴向负荷作用下，随着踝关节从中立位到15°跖屈，腓骨远端有向内、向前移动并内旋的趋势。同时，当踝关节从中立位到10°背屈时，腓骨远端有向外、向后移动并外旋的趋势。在联合负荷作用下，相对于单纯轴向负荷，腓骨远端相对于胫骨远端有向内、向后移动并外旋的趋势。
胫腓下联合存在微动。胫腓下联合的相对运动与踝关节位置和负荷模式相关。
