Arthroscopic assessment of occult intra-articular injury in acute ankle fractures.

Purpose: To arthroscopically assess the pattern and extent of intra-articular damage associated with ankle fractures.

Type Of Study: Prospective case series.

Methods: From 1989 to 1998, 48 consecutive patients with acute unstable ankle fractures underwent ankle arthroscopy followed by reduction and internal fixation. In addition, all injuries were categorized by specific osseous, ligamentous, and articular pathology, based on clinical and arthroscopic examination. Whenever possible, the fractures were classified according to Lauge-Hansen and Danis-Weber schemes.

Results: Traumatic articular surface lesions (TASLs), including chondral defects and osteochondral lesions measuring greater than 5 mm in diameter, were identified in 30 of the 48 ankles (63%), with 11 lesions localized to the tibia and 19 noted on the talus. The tibial lesions were at the posterior syndesmotic ligament insertion in 6 cases, at the anterior capsule origin in 3 cases, and at the central articular surface in 2 cases. Of the 19 talar lesions, 15 involved the medial dome and 4 involved the lateral articulation. TASLs of the talus in this series were uniformly unstable or displaced and virtually devoid of subchondral bone, precluding satisfactory internal fixation. Of the 10 pronation-external rotation fractures, 7 had articular surface defects with 5 involving the medial and 2 the lateral dome. Ten of the 24 supination-external rotation or Danis-Weber B fractures were found to have TASLs of the talus, 9 medial and 1 lateral. Nine of 12 fractures with syndesmosis disruptions sustained full-thickness damage to the talar chondral surface (P =.01).

Conclusions: Ankle fractures have a high incidence of concomitant intra-articular pathology with syndesmosis disruption portending a particularly high risk of articular surface injury to the talar dome. Arthroscopy is a valuable tool in identifying and treating intra-articular damage that would otherwise remain unrecognized and may provide prognostic information regarding the functional outcome of these injuries.