Dynamic Foot Bone Motion: Evaluation of Reconstructive Procedures

描述(由申请人提供)： 扁平足畸形(扁平足或足周半脱位)是美国最常见的足部疾病，影响各个年龄段的患者。由于该畸形通常含有肌肉腱成分，而且许多患者有糖尿病、高血压和肥胖史，因此扁平足的发病率呈上升趋势。对于跟骨周围半脱位的治疗还没有完全标准化，可能涉及制动、矫形术，严重的情况下还需要手术矫正。这些矫治手术可以包括以下手术的组合：肌腱转移或延长、足底内柱屈肌截骨、内柱稳定、各种后足截骨和/或后足关节置换术。值得注意的是，外科医生对执行哪些外科手术几乎没有达成一致意见。后足外翻的存在是一项重要的信息，因为无后足外翻的有症状的扁平足通常可以通过内侧柱稳定手术纠正；然而，如果存在后足外翻，则需要进行某种程度的跟骨截骨。虽然具体的截骨类型由扁平足畸形的病理决定，但最常见的后足截骨手术(内侧跟骨截骨术(MCO)、Evans跟骨截骨术和跟骨立方体牵引关节融合术(CCDA))都会导致前足外侧压力增加。对于后足外翻、前足外展和跟骨俯仰角正常(侧柱手术的禁忌症)的扁平苔藓来说，这些手术都不是理想的。此外，这些截骨术并不能直接控制所有三个平面的矫正。跟骨Z形截骨术已被证明可以在所有三个平面上矫正有后足内翻畸形的足部。最近，Z形截骨术被用来矫正扁平肌畸形。本组骨科医生目前的临床实践是采用改良的跟骨Z形截骨术治疗后足外翻、前足外展、跟骨俯仰角正常的扁平足畸形，但该方法尚未得到客观研究。本研究的目的是通过对跟骨截骨术(MCO和Evans)和Z形截骨术手术前后的骨位、关节轴线和足底压力的研究，比较两种截骨术的优劣。我们将使用高度专业化的双平面透视系统来跟踪感兴趣的脚部骨骼的运动。我们的具体目标是[1]改进我们现有的双平面透视系统，[2]研究三种可能的跟骨截骨术：MCO截骨术、Evans截骨术或Z跟骨截骨术(MCO、Evans或Z-跟骨截骨术)手术前后对照(中性对齐)足和扁平足的骨运动。我们有两个飞利浦BV-Pulsera C形臂，它们被配置为允许受试者在对脚进行成像时穿过两个系统的视野。我们的目标是开发新的软件来跟踪高速透视图像中的单个骨骼，用高速摄像机取代现有的CCD摄像机，并将X射线源和图像增强器安装在定制的柱子上，这将极大地增加我们的双平面系统的灵活性。我们将量化10个中性排列的受试者的足部骨骼运动学和足底压力。我们还将量化30名扁平足受试者手术前后的足部骨骼运动学和足底压力，其中10人将接受MCO、Evans跟骨截骨术或Z形截骨术。

DESCRIPTION (provided by applicant): Project Summary/Abstract The pes planus deformity (flatfoot or peritalar subluxation) is the most common foot condition affecting patients of all ages in the U.S. Since the deformity often has a musculotendinous component and many patients have a history of diabetes, hypertension and obesity, the incidence of flatfoot is on the rise. The treatment for peritalar subluxation is not wel-standardized and may involve immobilization, orthotics, and in severe cases, surgical correction. These corective surgeries may include combinations of the folowing: tendon transfers or lengthenings, medial column plantar flexor osteotomies, medial column stabilizations, various hindfoot osteotomies and/or hindfoot arthrodeses. Of note is that there is little agreement among surgeons as to which surgical procedures to perform. The presence of hindfot valgus is a critical piece of information, as symptomatic flatfeet without hindfot valgus can often be corected with a medial column stabilization procedure; however, if hindfoot valgus is present, some measure of calcaneal osteotomy is required. While the specific type of osteotomy is dictated by the pathology of the flatfoot deformity, the most common hindfoot osteotomies (the medializing calcaneal osteotomy (MCO), the Evans calcaneal osteotomy, and the calcaneocuboid distraction arthrodesis (CCDA)) can all lead to increased lateral forefoot pressure. None of these procedures are ideal for pes planus with hindfoot valgus, forefoot abduction and a normal calcaneal pitch angle (a contraindication for lateral column procedures). Additionally, these osteotomies do not offer direct control of correction in all three planes. The calcaneal Z-osteotomy has been demonstrated to allow for correction in all three planes in feet with a varus hindfoot deformity. Recently, the Z-osteotomy has been has been described for corection of the pes planus deformity. The current clinical practice of the orthopaedic surgeon in our group is to perform a modified form of the calcaneal Z-osteotomy to treat pes planus with hindfoot valgus, forefoot abduction and a normal calcaneal pitch angle; however, this procedure has not been objectively studied. The purpose of this study is to compare and contrast the well-established calcaneal osteotomies (MCO and Evans) with the Z-osteotomy by studying bone pose, joint axis and plantar pressure pre- and post- surgery. We will use a highly specialized biplane fluoroscopic system to track the motion of the foot bones of interest. Our Specific Aims [1] To refine our existing biplane fluoroscopic system and [2] To study the fot bone motion of control (neutrally aligned) feet and flatfeet pre- and post-surgery with one of three possible calcaneal osteotomies: the MCO, Evans or Z-calcaneal osteotomy. We have two Philips BV-Pulsera C-arms that are configured to allow a subject to walk through the field of view of both systems while the foot is imaged. We aim to develop new software to track individual bones in high-speed fluoroscopic images, replace the existing CCD cameras with high-speed cameras and mount the X-ray sources and image intensifiers on customized posts that will greatly increase the flexibility of our biplane system. We will quantify the foot bone kinematics and plantar pressures 10 neutrally aligned subjects. We will also quantify the pre- and post-surgical foot bone kinematics and plantar pressures of 30 flat foot subjects, 10 of which will undergo either an MCO, an Evans calcaneal osteotomy or a Z-osteotomy.