Martins Rita, Quental Carlos, Folgado João, Ângelo Ana Catarina, de Campos Azevedo Clara
IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal.
Hospital CUF Tejo, Av. 24 de Julho, 1350-352 Lisboa, Portugal.
Biology (Basel). 2022 Dec 8;11(12):1783. doi: 10.3390/biology11121783.
The Latarjet procedure is the most popular surgical procedure to treat anterior glenohumeral (GH) instability in the presence of large anterior glenoid bone defects. Even though the placement of the bone graft has a considerable influence on its efficacy, no clear indications exist for the best graft position. The aim of this study was to investigate the influence of the medial-lateral positioning of the bone graft on the contact mechanics and GH stability due to the bone block effect. Four finite element (FE) models of a GH joint, with a 20% glenoid bone defect, treated by the Latarjet procedure were developed. The FE models differed in the medial-lateral positioning of the bone graft, ranging from a flush position to a 4.5 mm lateral position with respect to the flush position. All graft placement options were evaluated for two separate shoulder positions. Anterior GH instability was simulated by translating the humeral head in the anterior direction, under a permanent compressive force, until the peak translation force was reached. Joint stability was computed as the ratio between the shear and the compressive components of the force. The lateralization of the bone graft increased GH stability due to the bone block effect after a 3 mm lateralization with respect to the flush position. The increase in GH stability was associated with a concerning increase in peak contact pressure due to the incongruous contact between the articulating surfaces. The sensitivity of the contact pressures to the medial-lateral positioning of the bone graft suggests a trade-off between GH stability due to the bone block effect and the risk of osteoarthritis, especially considering that an accurate and consistent placement of the bone graft is difficult in vivo.
拉塔热手术是治疗存在大型前盂肱（GH）骨缺损时前盂肱关节不稳定最常用的外科手术。尽管植骨的放置对其疗效有相当大的影响，但对于最佳植骨位置尚无明确的指征。本研究的目的是探讨由于骨块效应，植骨的内外侧定位对接触力学和GH稳定性的影响。建立了4个采用拉塔热手术治疗的有20%盂骨缺损的GH关节有限元（FE）模型。这些FE模型在植骨的内外侧定位上有所不同，范围从平齐位置到相对于平齐位置外侧4.5毫米的位置。对所有植骨放置选项在两个不同的肩部位置进行了评估。通过在永久压缩力下将肱骨头向前平移来模拟前GH不稳定，直到达到最大平移力。关节稳定性计算为力的剪切分量与压缩分量之比。相对于平齐位置外侧化3毫米后，由于骨块效应，植骨的外侧化增加了GH稳定性。GH稳定性的增加与由于关节面之间不协调接触导致的峰值接触压力的令人担忧的增加有关。接触压力对植骨内外侧定位的敏感性表明，在由于骨块效应导致的GH稳定性与骨关节炎风险之间存在权衡，特别是考虑到在体内难以准确且一致地放置植骨。
