近年来微创技术（髓内钉和经皮钢板固定）治疗肱骨骨折的病例逐渐增加，该技术难以获得骨折精确的旋转复位。我们研究发现微创术后＞20度的肱骨近端旋转畸形愈合发生率高达27.2%-40.9%，回顾性研究认为较大旋转畸形与肩关节远期退变有关，但缺乏实验证据，且尚无对继发肩袖病理变化的研究。.术后旋转畸形可由肱骨头后倾角数值量化，后倾角较对侧增大或减小表明肱骨近端内旋或外旋畸形。我们假设旋转畸形会改变肩袖与肩峰、喙突、喙肩韧带间隙及其力臂长度，使肩袖的生物力学环境变化，进而导致组织退变和损伤。拟通过构建包括周围肌肉群（三角肌、肩袖）的肩关节三维有限元模型和动物实验研究。.预期证实旋转畸形的方向和程度与肩关节活动中肩袖力学负荷变化相关，畸形可增加肌腱与肩峰、喙肩韧带和喙突之间的撞击，诱发组织退变并影响肩关节功能。从而重新审视微创技术治疗肱骨骨折的价值，为该骨折治疗进展提供新的借鉴和指导。

In recent years, minimally invasive techniques such as intramedullary nail and percutaneous plate osteosynthesis(Mipo) were popular in the treatment of humeral shaft fracture. However, minimally invasive operation lacks adequate intraoperative exposure, thus reduction error especially malrotation could not be avoided even under intraoperative image intensifier. A retrospective study suggested postoperative malrotation would affect the ipsilateral shoulder function. However but we have no experimental evidence on this result, nor secondary pathological changes of rotator cuff of shoulder with malrotation...Postoperative malrotation could be quantified by humeral head retroversion angle(HRA) changes. The increases or decreases of HRA suggest the proximal humeral internal or external malrotation. We assume that the malrotation will change the distance between rotator cuff and the acromion, coracoid process, coracoacromial ligament as well as the length of the muscular force arm. The disturbed biomechanical environment may lead to tissue degeneration and injury. We proposed to explore and analyze the assumption through establishing three-dimensional finite element model of shoulder with surrounding muscles(including deltoid, rotator cuff) and animal experiment..We expect to confirm that the direction and extent of malrotation will vary rotator cuff mechanical load during shoulder joint motion, and induce impingement of tendon to acromion , coracoacromial ligament and the coracoid process, which results in rotator cuff degeneration and shoulder detriment. We hope to provide a new aspective to evaluate the value of minimally invasive technique in treatment of humeral fractures.

【目的】:通过并建立三维有限元计算机模型分析肱骨干骨折旋转畸形愈合后引起的肩关节生物力学环境的变化趋势。并通过建立兔动物医源性肱骨近端旋转畸形（后倾角改变）的肩关节模型，并分析该骨性结构变化对肩袖组织的影响；【方法】:通过CT获得健康成人肩关节及同侧肱骨全长扫描Dicom数据，通过Mimics和Marc软件建立三维有限元肩关节骨与软组织模型，分别模拟肱骨三角肌止点水平上方和下方截骨后骨折近端旋转畸形愈合，分析骨折后旋转移位引起的肩关节生物力学变化。16只新西兰白兔随机分为实验（A组）和对照组B组，实验组使骨折近端分别20度的向内旋转对位畸形，对照组使骨折端解剖复位，制造骨折后以小钢板固定，骨折愈合后使患侧主被动活动，20周后处死动物取肩袖标本，行病理切片观察。【结果】：三维有限元力学分析提示，存在肱骨近端内旋20度畸形情况下，肩关节内旋40度时，关节面应力为正常的7-9倍。动物实验证实：存在肱骨近端外内旋20度畸形情况下，肩关节外旋40度时，关节面应力为正常的3-5倍。内向旋转畸形可造成肩关节活动中肩袖力学负荷增加，畸形可增加肌腱与肩峰、喙肩韧带和喙突之间的撞击，诱发组织退变并影响肩关节功能。