CORTICAL DEFECT OF THE DISTAL FIBULA - VARIANT OF OSSIFICATION

PURPOSE: To elucidate the nature of a normally occurring cortical defe ct of the distal fibula. MATERIALS AND METHODS: In patients with sprai n and nonspecific ankle pain during a 2-year period, the authors revie wed ankle radiographs, computed tomographic (CT) scans, and magnetic r esonance (MR) images. Cases were added from our file. Dried skeletons and cadavers were evaluated with radiography for the presence of this cortical defect. RESULTS: Fifteen (1,8%) of 847 radiographs in 739 pat ients (male, 377; female, 362; age range, 15-84 years) showed a small cortical defect in the anterior aspect at the level of the distal tibi ofibular joint. The age range of the subjects with the defect (male, f our; female, 11) was 16-66 years. MR imaging in two patients showed a small low-signal-intensity area at the insertion site of the anterior tibibofibular ligament Evaluation of 148 skeletons (75 subjects) revea led similar cortical defect in two cases (1.4%). CONCLUSION: The corti cal defect of the distal fibula, at the insertion she of the anterior tibiofibular ligament has no-clinical significance and should not be c onfused with neoplasm.