Isolated fracture of the posterolateral tibial lip (Volkmann's triangle)

To retrospectively evaluate the underlying pathomechanism of isolated fracture of the posterolateral tibial lip (Volkmann's triangle), and to demonstrate associated radiographic methods.

Retrospective analysis of 2500 ankle lesions showed an isolated fracture of the dorsal tibial lip in 25 cases. Distal tibial lesions of growing individuals were not considered. All patients were examined by radiography in internal oblique and lateral views.

Sixteen of 25 patients had had their accident during winter; 11 had slipped on ice or snow. All 25 patients showed a closed ankle lesion in the correct joint position with no clinical signs of instability. Evaluation of the standard images showed isolated fracture of the posterolateral tibial lip in 24 patients. The fracture was best recognized in the standard lateral view in 22 patients. In 2 patients the lateral stress projection demonstrated the fracture (20 degrees internal rotation). In one case the fracture was only seen on axial CT images. Twenty-two patients with small wedge fragments were treated conservatively; 3 with a displaced and large fragment had surgical revision and stabilization. Sixteen cases were examined by conventional radiography at follow-up examination and 5 of these showed radiological signs of arthrosis.

Plain conventional radiography is still necessary in the primary diagnosis of ankle joint lesions. The isolated fracture of the dorsal tibial margin is best seen in the standard lateral view. Indication for CT in routine diagnostics is limited to cases showing clinical evidence of ankle injury without roentgenological signs of a fracture in the standard images. Differential diagnoses include the pilon lesion and the Maison-neuve-type fracture.