Mulcahy D M, McCormack D M, Stephens M M
Foot and Ankle Surgery, Wellesley Central Hospital, Toronto, Ontario, Canada.
Foot Ankle Int. 1998 Dec;19(12):842-8. doi: 10.1177/107110079801901209.
Intra-articular calcaneal fractures are associated with significant long-term morbidity, and considerable controversy exists regarding the optimum method of treating them. The contact characteristics in the intact subtalar joint were determined at known loads and for different positions of the ankle and subtalar joint, using pressure-sensitive film (Super Low; Fuji, Itochu Canada Ltd, Montreal, Quebec). We measured the contact area to joint area ratio (pressure > 5 kg force/cm2 [kgf/cm2]) which normalizes for differences in joint size and the ratio of high pressure zone (>20 kgf/cm2) as a reflection of overall increase in joint pressure. Three simulated fracture patterns were then created and stabilized with either 1 or 2 mm of articular incongruity. Eight specimens were prepared with a primary fracture line through the posterior facet, eight with a joint depression-type fracture, and six with a central joint depression fracture. A measure of 1 to 2 mm of incongruity in the posterior facet for all three fracture patterns produced significant unloading of the depressed fragment, with a redistribution of the overall pattern of pressure distribution to parts of the facet that were previously unloaded.
跟骨关节内骨折与严重的长期致残率相关，并且关于其最佳治疗方法存在相当大的争议。使用压敏膜（超低敏型；富士公司，伊藤忠商事加拿大有限公司，蒙特利尔，魁北克），在已知负荷以及踝关节和距下关节的不同位置下，测定完整距下关节的接触特性。我们测量了接触面积与关节面积之比（压力>5千克力/平方厘米[kgf/cm²]），该比值可对关节大小差异进行归一化处理，以及高压区比值（>20 kgf/cm²），以反映关节压力的总体增加情况。然后创建三种模拟骨折模式，并用1或2毫米的关节不平整进行固定。制备了8个标本，其主要骨折线穿过后关节面，8个为关节凹陷型骨折，6个为中央关节凹陷骨折。对于所有三种骨折模式，后关节面1至2毫米的不平整测量结果显示，凹陷骨折块明显卸载，压力分布的整体模式重新分布到先前未加载的关节面部分。
