Xu Jian, Abdullah Abdullah, Alkhatib Nedal, Huang Yan, Xie Dawang, Deng Zhiqin, Deng Zhenhan
Department of Orthopaedics, The Fourth Affiliated Hospital of Guangxi Medical University, Liuzhou Workers' Hospital Liuzhou, Guangxi, China.
Orthopedic Department, Toronto Western Hospital Toronto, Ontario, Canada.
Am J Transl Res. 2021 Nov 15;13(11):12834-12842. eCollection 2021.
The surgical treatment for stage II adult acquired flat foot deformity (AAFD) remains controversial. Biomechanical effects of medial column stabilization remain unclear. No study has biomechanically assessed the effect of medial column arthrodesis on the whole foot. Our study aimed to mechanically analyze the advantages and disadvantages of this. Stage IIa and IIb AAFD three-dimensional finite element models were established. The application of Geomagic software, Solidwork software, and Abaqus software was used to simulate a medial column stabilization operation (navicular-cuneiform joint fusion, metatarsal-cuneiform joint fusion, or both). The maximum pressure on plantar soft tissue, medial column bone, and medial ligaments was compared before and after simulated single-foot weight loading. Several data were measured to carry out a comprehensive comparison. The maximum plantar stress was located under the first metatarsal head after the simulated medial column stabilization operation. It increased significantly after medial column stabilization in a stage IIa flatfoot model, but did not change significantly after medial column stabilization in stage IIb model. Therefore, after medial column fusion, the stress of the corresponding joint was reduced, but it was increased in the adjacent joints of the medial column. The stresses on medial ligaments and plantar fascia were also not alleviated after medial column fusion. Our results showed isolated medial column stabilization surgery cannot help patients with stage IIa nor IIb flatfoot from the biomechanical point of view, and such stabilization increases stress on the sole, the joints around the fusion sites, medial soft tissue, and ligaments. It can only be used as a combined surgery to stabilize joints with excessive motion and correct the deformity of supination of the forefoot.
II期成人获得性平足畸形（AAFD）的手术治疗仍存在争议。内侧柱稳定的生物力学效应尚不清楚。尚无研究从生物力学角度评估内侧柱关节融合对整个足部的影响。我们的研究旨在从力学角度分析其利弊。建立了IIa期和IIb期AAFD的三维有限元模型。应用Geomagic软件、Solidwork软件和Abaqus软件模拟内侧柱稳定手术（舟楔关节融合、跖楔关节融合或两者联合）。比较模拟单足负重前后足底软组织、内侧柱骨和内侧韧带的最大压力。测量了多个数据进行综合比较。模拟内侧柱稳定手术后，最大足底应力位于第一跖骨头下方。在IIa期扁平足模型中，内侧柱稳定后最大足底应力显著增加，但在IIb期模型中内侧柱稳定后无显著变化。因此，内侧柱融合后，相应关节的应力降低，但内侧柱相邻关节的应力增加。内侧柱融合后内侧韧带和足底筋膜的应力也未得到缓解。我们的结果表明，从生物力学角度来看，单纯的内侧柱稳定手术对IIa期和IIb期扁平足患者均无帮助，而且这种稳定会增加足底、融合部位周围关节、内侧软组织和韧带的应力。它只能作为一种联合手术来稳定运动过度的关节并纠正前足内旋畸形。
