Focal fibrocartilaginous dysplasia associated with tibia vara

Focal fibrocartilaginous dysplasia of the tibia at the insertion of the pes anserinus (the expanded tendinous insertion of the gracilis, sartorius, and semitendinous muscles) is a rare unilateral lesion with a characteristic deformity of the proximal tibial metadiaphysis. It is associated with unilateral tibia vara in toddlers. Three cases of this entity are described, and the radiologic features are presented. Recognition of this disease is important because the response to conservative therapy is excellent.