基于髌股关节三维运动瞬时旋转轴的髌股关节疾病生物力学发病机制研究

The leading cause for patellofemnoral disease, which is with high incidence and poor curative effect, lies in its unclear biomechanical pathogenesis. Patellofemoral malalignment, which leads to abnormal stress distribution of the patellofemoral articular surfaces, is an important pathogen. But the past criterions for the determination of patellofemoral malalingment only focus on the matching of the patellofemoral articular surfaces, which isn't consistent with the essence of the patellofemoral biomechanics. Basically, muscle force moment acting on the patellofemoral joint is the driver of joint movement and stress. The moment is a product of the quadriceps force with its arm which is the vertical distance of quadriceps force line to the Patellofemoral rotational axis during flexion and extension. Therefore, the rotational axis plays an important role in the patellofemoral biomechanics, and is a reasonable reference line to assess patellofemoral malalingment. Based on this hypothesis, a research program is set to reveal the patellofemoral biomechanical pathogenesis: firstly, patellofemoral tracing and the rotational axis are observed with in vivo movement measurement techniques; then differerces of patellofemoral track, rotational axis, and stress distribution between normal people and patients with patellofemoral disease will be analyzed; finally, the relationship between the patelloferal rotational axis and the knee anatomical landmarks will be analysed to propose a reference axis for clinical diagnosis and treatment, and to provide a biomechanical insight into the patellofemoral malalignment.

髌股关节疾病发病率高，导致其疗效差的根本原因在于其生物力学发病机制不清。因髌股关节排列紊乱(malalignment)造成的应力分布异常是其发病机制的重要因素，但既往仅仅以关节面的匹配程度作为判断髌股关节排列紊乱的标准，忽视了髌股关节力学环境与髌股关节疾病内在联系的本质。作用于髌股关节的力矩才是驱动关节运动、产生关节面应力的掌控者，该力矩为股四头肌合力与力臂的乘积，其力臂为股四头肌力线与髌股关节旋转轴的垂直距离。故应将以此旋转轴视为髌股关节运动的核心，并作为评估排列紊乱的参照基准更为科学。本项目拟应用三维活体运动测量技术分析髌股关节运动轨迹，测定髌股关节旋转轴线；再以旋转轴线为参照基准，对比分析正常与排列紊乱患者髌骨轨迹、旋转轴及关节面应力分布的差异；并根据该旋转轴与膝关节解剖标志空间位置的相关性，提出适用于临床应用的旋转轴；为研究髌股关节疾病生物力学发病机制提供定量科学依据。

髌股关节疾病发病率高，既往仅仅以其关节面间的匹配程度作为判断髌股关节解剖结构异常和排列紊乱的标准，本课题组认为应将髌股关节旋转轴视为其运动的核心，并作为评估髌股关节的参照基准更为科学。项目获得批准后，项目负责人积极组织项目组成员进行开题论证，并按照计划书内容进行分工。截止2016年12月份，已经按计划完成任务书所有研究内容，取得研究成果包括：①研发膝关节薄层磁共振扫描方法，使扫描层厚小于1mm，为进行膝关节三维重建提供高清晰图像；②研发高屈膝角度膝关节磁共振扫描方法，为构建准动态膝关节三维运动模型提供影像基础；③开发磁共振图像专用图像分割工具“3D-livewire”的使用方法，用于构建精准的膝关节三维模型；④研发“基于间断膝关节三维影像构建准动态膝关节三维运动模型”的方法；⑤明确“基于间断膝关节三维影像构建准动态膝关节三维运动模型”所需膝关节角度位置的数量，基于大于等于5个间断“角度位置”的膝关节三维静态图像，可获得较为精确的膝关节准动态三维运动轨迹；⑥确立髌股关节旋转轴的计算方法，研发髌股关节旋转轴计算程序及软件；⑦计算正常人群的髌股关节旋转轴及其与股骨通髁线的解剖的相关性，正常人群组中，旋转轴与通髁线的空间夹角为6.80±4.41°；⑧计算正常人群与髌股关节疾病患者的髌股关节旋转轴的差异，复发性脱位组旋转轴与通髁线的空间夹角为26.03±18.84°、习惯性脱位组为17.62±10.78°、膝前痛组为15.97±8.24°，与正常组具有显著统计学差异；⑨计算正常人群与髌股关节疾病组的髌股关节应力分布差异，病例组的应力分布不均匀，存在应力集中区域；⑩建立适用于临床应用的髌股关节解剖旋转轴及髌股关节疾病评价方法，结果显示髌股关节旋转轴与股骨通髁线具有相关性，这可作为评价髌股关节解剖结构优劣、评估髌股关节疾病程度的便捷、准确的方式。