Dykyj D
Division of Basic Sciences, New York College of Podiatric Medicine, New York.
Clin Podiatr Med Surg. 1989 Jan;6(1):1-15.
HAV is a joint deformity that has some very characteristic anatomic features but that may be developed from a variety of interactive causes, both anatomic and functional. In the normal condition, the first metatarsal bone and hallucal phalanges form an axial array of bones. At the first metatarsophalangeal joint this arrangement is stabilized by a set of muscles whose tendons surround the joint. The pathology is associated with the deviation of the bones from their axial position and the related destabilization of the muscle group around the joint, specifically: (1) The hallux deviates and rotates laterally, while the first metatarsal deviates medially and also rotates laterally to some degree. (2) Deviation of the two main segments of the joint causes tearing and weakening of the medial capsular fibers and pulls the sesamoid bones and metatarsal head away from their normal plantar articulation. (3) Abnormal articulation of the sesamoid bones under the crista and pressure of the medial capsular wall cause erosion of cartilage and subchondral bone on the metatarsal head. (4) Deviation of the hallux redistributes the tendon insertions in relation to the joint axes of motion such that they serve to aggravate the deviation. (5) The deviated position of the hallux and eccentric actions of the tendons create a reaction force on the metatarsal head that serves to further medially displace the first metatarsal bone.
拇外翻是一种关节畸形，具有一些非常典型的解剖学特征，但可能由多种解剖学和功能性的相互作用原因导致。在正常情况下，第一跖骨和拇趾趾骨形成一组轴向排列的骨骼。在第一跖趾关节处，这种排列通过一组肌腱环绕关节的肌肉得以稳定。其病理变化与骨骼偏离轴向位置以及关节周围肌肉群的相关失稳有关，具体如下：（1）拇趾向外偏斜并向外旋转，而第一跖骨向内偏斜且也有一定程度的向外旋转。（2）关节两个主要部分的偏斜导致内侧关节囊纤维撕裂和减弱，并将籽骨和跖骨头从其正常的跖侧关节连接处拉开。（3）籽骨在嵴下的异常关节连接以及内侧关节囊壁的压力导致跖骨头软骨和软骨下骨的侵蚀。（4）拇趾的偏斜重新分布了与关节运动轴相关的肌腱附着点，从而加剧了偏斜。（5）拇趾的偏斜位置和肌腱的偏心作用在跖骨头上产生一个反作用力，进一步使第一跖骨向内移位。
