Anterolateral compartment of the ankle in the lateral impingement syndrome: appearance on CT arthrography.

Abstract

This article describes the appearance of the anterolateral recess of the posttraumatic ankle on CT arthrography and clearly shows the benefit of this technique in the diagnosis of soft-tissue impingement. The study was carried out on 44 patients examined by CT arthrography and arthroscopy for chronic, posttraumatic ankle pain. The analysis principally concerned the lateral compartment--in particular, the synovial regularity and the cartilage of the talar dome. Four CT patterns were identified: type 0, uniform filling of the recess with clear limits; type I, intraarticular linear structure outlined by contrast agent; type II, nodular formation in the lateral groove; and type III, irregular appearance of the edges of the lateral groove. Ninety-one percent (10/11) of type II patterns were characterized as meniscoid lesions by arthroscopic examination, 100% (14/14) of type III patterns corresponded to an abundant fibrous reaction, and arthroscopic findings were normal for 100% (2/2) of type 0 patterns and 88% (15/17) of type I patterns. The latter was thus considered as a normal variant outlining the accessory anterior inferior tibiofibular ligament. Type II and III lesions were statistically associated (p = .001) with a chondropathy when time from initial trauma was greater than 22 months. CT arthrography provides evidence of anterolateral soft-tissue impingement--in particular, in type II or III patterns. These lesions are statistically associated with a chondropathy.