A clinicopathologic study of bony spurs on the pes anserinus.

Nineteen cases of exostoses located on part of the pes anserinus were studied clinically and histologically. All lesions were resected during surgery between 1965 and 1985. In these 19 cases, 14 had involvement of the tibia only at the insertion of the pes anserinus. Five had multiple exostoses with pes anserinus involvement. All exostoses occurring only in pes anserinus showed an icicle appearance in roentgenography and had no detectable cartilage cap. On the other hand, exostoses in patients with multiple exostoses (osteochondromas) showed varying appearances in roentgenography and had cartilage caps on their surfaces. Exostoses occurring only in the pes anserinus may or may not be osteochondromata and could be classified as pes anserinus bony spurs.