Cortical defect of the distal fibula: variant of ossification.
OBJECTIVE
To elucidate the nature of a normally occurring cortical defect of the distal fibula.


METHODS
In patients with sprain and nonspecific ankle pain during a 2-year period, the authors reviewed ankle radiographs, computed tomographic (CT) scans, and magnetic resonance (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 patients (male, 377; female, 362; age range, 15-84 years) showed a small cortical defect in the anterior aspect at the level of the distal tibiofibular joint. The age range of the subjects with the defect (male, four; 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 tibiofibular ligament. Evaluation of 148 skeletons (75 subjects) revealed similar cortical defect in two cases (1.4%).


CONCLUSIONS
The cortical defect of the distal fibula, at the insertion site of the anterior tibiofibular ligament, has no clinical significance and should not be confused with neoplasm.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016512:Ankle Injuries / Q000175:diagnosis / Q000000981:diagnostic imaging; D000843:Ankle Joint / Q000000981:diagnostic imaging / Q000473:pathology; D001847:Bone Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging; D001859:Bone Neoplasms / Q000175:diagnosis / Q000000981:diagnostic imaging; D003937:Diagnosis, Differential; D005260:Female; D005360:Fibula / Q000000981:diagnostic imaging* / Q000473:pathology*; D006801:Humans; D008023:Ligaments, Articular / Q000000981:diagnostic imaging / Q000473:pathology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010012:Osteogenesis; D010146:Pain / Q000175:diagnosis / Q000000981:diagnostic imaging; D011446:Prospective Studies; D012189:Retrospective Studies; D013180:Sprains and Strains / Q000175:diagnosis / Q000000981:diagnostic imaging; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology; D014057:Tomography, X-Ray Computed