Etiology of the anterior ankle impingement syndrome: a descriptive anatomical study.

BACKGROUND: In the anterior ankle impingement syndrome, recurrent traction to the anterior joint capsule is stated to be the cause of formation of talotibial osteophytes. This hypothesis involves the assumption that the osteophytes originate at the site where a capsular attachment is located. A soft tissue component that can get squeezed between the distal tibia and talus is thought to be responsible for impingement complaints during dorsiflexion movements.
METHODS: In eight ankle specimens, the width of the nonweightbearing tibial cartilage rim and the distance of the tibial and talar cartilage to the capsular attachment were measured. The relationship of the soft tissue components to the anterior joint was studied. The average tibial cartilage rim width was 2.4 mm (1.5-3.0 mm). Tibial and talar cartilage-capsule distances were 4.3 mm (0.5-9.0 mm) and 2.4 mm (1.8-3.3 mm), respectively. In all specimens, the anterior joint space contained a triangular soft tissue component, overlying the joint capsule. The component consisted of a synovial membrane and subsynovial located fat and collagen tissue. It was observed that in 15 degrees dorsiflexion the soft tissue component was squeezed between the tibia and talus.
CONCLUSIONS: The anterior ankle joint capsule attaches proximal to the site where the anterior talotibial spurs originate. The hypothesis of formation of talotibial spurs due to repetitive capsule traction therefore does not seem plausible. The anatomic findings do support the hypothesis that an anteriorly located soft tissue component is present that can give impingement symptoms.