Camarda Lawrence, Martorana Umberto, D'Arienzo Michele
Orthopedic and Traumatology Unit, University of Palermo, Via del Vespro, Palermo, Italy.
Orthopedics. 2009 Jul;32(7):530. doi: 10.3928/01477447-20090527-25.
A subtalar dislocation of the foot is an uncommon injury, and cases of posterior subtalar dislocation are even rarer. This injury is characterized by a simultaneous dislocation of talocalcaneal and talonavicular joints while tibiotalar and calcaneocuboid articulations remain intact. Subtalar dislocation is commonly accompanied by fractures of the malleoli, talus, or fifth metatarsal and by a rotational component of the subtalar joint. Subtalar dislocation can occur in any direction and produces significant deformity. This article presents a case of pure posterior subtalar dislocation in an 80-year-old man who presented with pain and deformity in his left ankle following a motorcycle accident. Radiographs demonstrated dislocation of both the talonavicular and talocalcaneal joints. The calcaneus was displaced posteriorly without medial or lateral displacement. No rotational component of the calcaneus was noted, suggesting the trauma was in pure hyperplantar flexion. We hypothesize that pure hyperplantar flexion could lead to a progressive subtalar ligament weakening that may result in a complete ligament rupture if the plantar flexion force is prolonged. This could be observed in the presence of good bone quality and if the force is applied distally at the navicular bone.
距下关节脱位是一种罕见的足部损伤，而后方距下关节脱位的病例更为罕见。这种损伤的特征是距跟关节和距舟关节同时脱位，而胫距关节和跟骰关节保持完整。距下关节脱位常伴有踝关节骨折、距骨骨折或第五跖骨骨折，以及距下关节的旋转成分。距下关节脱位可发生于任何方向，并产生明显畸形。本文报道了一例80岁男性单纯后方距下关节脱位的病例，该患者在摩托车事故后出现左踝疼痛和畸形。X线片显示距舟关节和距跟关节均脱位。跟骨向后移位，无内外侧移位。未发现跟骨的旋转成分，提示创伤为单纯极度跖屈。我们推测，单纯极度跖屈可能导致距下关节韧带逐渐减弱，如果跖屈力持续存在，可能导致韧带完全断裂。在骨质良好且力作用于舟骨远端的情况下可观察到这种情况。
