Anatomical study for an updated comprehension of clubfoot. Part II: Ligaments, tendons and muscles

Purpose The aim of our study was to evaluate the pathological anatomy of the ligaments, tendons and muscles in clubfeet, and to show whether the dysbalance of shortened and elongated structures is an adaptive process or a primary factor inducing the misshaped bones and cartilagines. Methods Surgical exposure was performed on seven idiopathic clubfeet specimens, aborted between the 25th and 37th week of gestation and compared to two normal feet (27th and 36th week of gestation). Results The medial stabilisation system of the foot was found shortened, but all ligaments could be dissected. On the lateral side, the calcaneofibular ligament in particular was both 'shortened' and 'elongated', depending on the course of the fibres to the axis of motion in the subtalar and talocalcaneonavicular joint. The main difference to the normal feet was found in the thickened tendon of the tibialis posterior forming a bulbus before dividing into fascicules. Conclusions We presume the ossification disturbance of the calcaneus to be the primary fault. This disturbance will influence the reduction of the varus position, so ligaments and tendons will be conformed to the misshaped bones.