Jastifer James R, Gustafson Peter A, Labomascus Aaron, Snoap Tyler
Orthopedic Surgeon, Borgess Orthopedics, Kalamazoo, MI.
Associate Professor, Mechanical and Aeronautical Engineering, Western Michigan University, Kalamazoo, MI.
J Foot Ankle Surg. 2017 Jul-Aug;56(4):773-775. doi: 10.1053/j.jfas.2017.02.019.
The ball and socket ankle joint is a morphologically abnormal joint characterized by rounding of the articular surface of the talus. Other than anecdotal observation, little evidence has been presented to describe the development of this deformity. The purpose of the present study was to review ankle and subtalar joint mechanics and to kinematically examine the functional combination of these joints as a mechanism of the ball and socket ankle deformity. We reviewed functional representations of the ankle joint, subtalar joint, and ball and socket ankle deformity. A computational study of joint kinematics was then performed using a 3-dimensional model derived from a computed tomography scan of a ball and socket deformity. The joint kinematics were captured by creating a "virtual map" of the combined kinematics of the ankle and subtalar joints in the respective models. The ball and socket ankle deformity produces functionally similar kinematics to a combination of the ankle and subtalar joints. The findings of the present study support the notion that a possible cause of the ball and socket deformity is bony adaptation that compensates for a functional deficit of the ankle and subtalar joints.
球窝踝关节是一种形态异常的关节，其特征为距骨关节面呈圆形。除了轶事性观察外，几乎没有证据描述这种畸形的发展情况。本研究的目的是回顾踝关节和距下关节的力学，并从运动学角度研究这些关节的功能组合，以此作为球窝踝关节畸形的一种机制。我们回顾了踝关节、距下关节以及球窝踝关节畸形的功能表现。然后，利用从球窝畸形的计算机断层扫描获得的三维模型，进行了关节运动学的计算研究。通过在各个模型中创建踝关节和距下关节联合运动学的“虚拟图谱”来捕捉关节运动学。球窝踝关节畸形产生的运动学在功能上类似于踝关节和距下关节的组合。本研究结果支持这样一种观点，即球窝畸形的一个可能原因是骨适应性改变，以补偿踝关节和距下关节的功能缺陷。
