[The painful os intermetatarseum].

The os intermetatarseum is an uncommon accessory bone of the foot, usually found between the bases of the first and second metatarsal bones. Two cases of a painful os intermetatarseum in athletes are reported. Surgical excision of the os intermetatarseum relieved the pain in both patients. Case reports concerning athletes with a painful os intermetatarseum are rare. An os intermetatarseum should be taken under consideration when evaluating dorsal midfoot pain.