[Talus fractures--fractures of the most important tarsal bone].
The talus is the key bone of the foot due to its location between the ankle and the subtalar joints. Through the flexion and extension of the ankle joint, the talus is the "propulsive bone" situated at the root of the first ray and the hallux. Through the subtalar and talo-navicular joints, the talus allows the foot to be "suspended" using a fancy spring mechanism involving ligaments and tendons. The talus thus transmits forces through two important joints without any direct muscular constraint. The talo-calcaneo-navicular joint may be called the "coxa pedis" due to the anatomical and functional similitudes with the coxofemoral joint ("coxa pelvis"). Fractures of the talus are rare. Talus fractures can be classified in "central" and "peripheral" fractures. Central fractures occur through a strong axial blow provided that the ankle and coxa pedis are locked by extrinsic muscular contraction. Peripheral fractures instead occur in an extreme position of the ankle or the coxa pedis, with a subluxation or complete dislocation of one or more of those joints. Central fractures produce a bony solution of continuity in between at least two of the ankle, subtalar and talo-navicular joints. Peripheral fractures mostly do implement joint surfaces which are sheared off. Aim of treating talus fractures is precise and stable reduction of the fragments because most often, the fractures cross the articular layers. The surgical approaches are critical, especially in displaced central fractures, because the reduction may require visual control all around the bone. There are three approaches which might be used as single approaches or combined simultaneously: the anteromedial approach along the subtalar joint from the navicular to the retro-malleolar region, the anterolateral approach centered on the sinus tarsi (Ollier) and the postero-lateral approach (Gallie). In many cases, a joint distraction device may help visualization of the different joint spaces as well as assist reduction of dislocations. Early joint mobilization, without weight bearing may be very profitable for good functional results. Aseptic necrosis (AVN) of the talus do not need special care if asymptomatic. On the long run, open operative arthrolysis might be added to the eventual removal of implants to considerably improve the results.
Klaue
K
K
Reparto di Chirurgia Ortopedica, Clinica Luganese, sede Moncucco, Lugano. k.klaue@bluewin.ch
D000328:Adult; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal; D050723:Fractures, Bone / Q000145:classification / Q000000981:diagnostic imaging / Q000601:surgery; D006801:Humans; D004204:Joint Dislocations / Q000175:diagnosis; D008297:Male; D011859:Radiography; D013628:Talus / Q000033:anatomy & histology / Q000000981:diagnostic imaging / Q000293:injuries* / Q000502:physiology; D013997:Time Factors