Sarmiento A, Latta L L, Tarr R R
Instr Course Lect. 1984;33:83-106.
A mechanically based classification system and hypothesis for fracture healing with peripheral callus has been proposed based on many years of clinical experience and numerous laboratory research studies. This hypothesis describes the interactions and influences on fracture healing from the vascular, mechanical, electric, chemical, and thermal environments in specific callus regions surrounding the fracture site. The central theme to this phenomenon is motion at the fracture site. The single factor distinguishing the effects of closed functional bracing of fractures from all other treatment modalities is motion between the fragments which results from early functional activity. Perhaps the stimulus to a prolonged inflammatory response is provided by friction between moving fracture fragments and the surrounding tissues. An increased vascular response results, and environmental factors are stimulated to form an abundant peripheral callus. Three distinct callus zones exist which provide overlapping stages of healing based on structure and optimized physiologic conditions. Clinical signs and symptoms, such as fracture stability as well as motion and pain at the fracture site, combine to provide the optimum feedback mechanism to control functional activity, which in turn governs environmental factors. Roentgenographic appearance can be better judged for mechanical significance if these three callus regions are appreciated. In animals as well as in humans, if function has correctly influenced the environment during callus formation, refracture strength is often greater than that of the original bone.
基于多年的临床经验和大量的实验室研究，已经提出了一种基于力学的骨折愈合分类系统及伴有外周骨痂的骨折愈合假说。该假说描述了骨折部位周围特定骨痂区域内血管、力学、电学、化学和热环境对骨折愈合的相互作用和影响。这一现象的核心主题是骨折部位的活动。骨折闭合功能支具与所有其他治疗方式效果的唯一区别因素是早期功能活动导致的骨折碎片之间的活动。也许骨折活动碎片与周围组织之间的摩擦会引发持续的炎症反应。继而血管反应增强，刺激环境因素形成丰富的外周骨痂。存在三个不同的骨痂区域，根据结构和优化的生理条件提供重叠的愈合阶段。临床体征和症状，如骨折稳定性以及骨折部位的活动和疼痛，共同构成控制功能活动的最佳反馈机制，而功能活动又反过来支配环境因素。如果了解这三个骨痂区域，就能更好地判断X线表现的力学意义。在动物和人类中，如果在骨痂形成过程中功能正确地影响了环境，再次骨折时的强度往往大于原始骨骼的强度。
