Hughes Matthew, Bernard Jason, Szarko Matthew
St Georges, University of London, Cranmer Terrace, London SW17 0RE, United Kingdom.
Department of Orthopaedics, St Georges Hospital, Blackshaw Road, London SW17 0QT, United Kingdom.
Spine Deform. 2018 Mar-Apr;6(2):99-104. doi: 10.1016/j.jspd.2017.07.002.
An in vitro biomechanical study into the effect of rib deconstruction on the flexibility in ovine ribs, using three-point bending.
To examine the feasibility and possible effectiveness of a more conservative costoplasty using an in vitro animal model.
Costoplasty remains useful in the treatment of adolescent idiopathic scoliosis, rib hump, and associated chest wall deformities. However, traditional costoplasty increases morbidity and blood loss.
Ribs 2-10 were dissected from four fresh half ovine rib cages. The ribs were randomly allocated to Groups 1 to 4. The ribs underwent deconstruction, 10 mm from the lateral tubercle and 30 mm long, according to their group: Group 1 = control; Group 2 = convex cortical bone removed; Group 3 = convex cortical and cancellous bone removed; Group 4 = all but the ventral cortex is removed. Flexibility was tested by loading the concave side of each rib while fixed at the rib head and equidistant from the center of the resected area. The ribs were deformed at 0.5 mm/s up to a maximum load of 9.99 kg or fracturing. Load was plotted against displacement to find the load/displacement coefficient for each group. Statistical analysis was by an analysis of variance with Tukey's honestly significant difference post hoc testing.
The load/displacement coefficients were as follows: Group 1 = 131.93 (±27.52) N/mm, Group 2 = 93.36 (±40.71) N/mm, Group 3 = 88.66 (±25.84) N/mm, and Group 4 = 29.69 (±29.11) N/mm. Group 4 was significantly less stiff than Groups 1, 2, and 3 (p < .01). No ribs in Groups 1, 2, and 4 fractured. Five of 8 ribs in Group 3 fractured during loading.
Deconstructing the rib down to the concave side significantly increases the flexibility by approximately 4.5 times. Despite large removal of bone, it retains the ability to withstand 10 kg of load without fracture.
一项体外生物力学研究，采用三点弯曲法探究肋骨解构对绵羊肋骨柔韧性的影响。
使用体外动物模型检验一种更保守的肋骨成形术的可行性和可能的有效性。
肋骨成形术在青少年特发性脊柱侧凸、肋骨隆突及相关胸壁畸形的治疗中仍具有重要作用。然而，传统的肋骨成形术会增加发病率和失血量。
从四个新鲜的半绵羊肋骨笼中解剖出第2至10根肋骨。将肋骨随机分为1至4组。根据分组情况，在距外侧结节10毫米处进行30毫米长的肋骨解构：第1组 = 对照组；第2组 = 去除凸侧皮质骨；第3组 = 去除凸侧皮质骨和松质骨；第4组 = 除腹侧皮质外全部去除。在将每根肋骨固定于肋骨头并与切除区域中心等距的同时，通过加载肋骨凹侧来测试柔韧性。肋骨以0.5毫米/秒的速度变形，直至达到9.99千克的最大负荷或发生骨折。绘制负荷与位移的关系图，以确定每组的负荷/位移系数。采用方差分析及Tukey真实显著性差异事后检验进行统计分析。
负荷/位移系数如下：第1组 = 131.93（±27.52）牛/毫米，第2组 = 93.36（±40.71）牛/毫米，第3组 = 88.66（±25.84）牛/毫米，第4组 = 29.69（±29.11）牛/毫米。第4组的刚度明显低于第1、2和3组（p < 0.01）。第1、2和4组中没有肋骨骨折。第3组的8根肋骨中有5根在加载过程中骨折。
将肋骨解构至凹侧可显著提高柔韧性，约为原来的4.5倍。尽管大量去除了骨质，但它仍能承受10千克的负荷而不发生骨折。
