Apart from the exposure and prominence of the medial side of the first metatarsal head commonly seen in association with hallux valgus (and referred to as a first metatarsal head exostosis), several exostoses may give rise to trouble in adolescence:
- Calcaneal exostosis Prominence of the calcaneus above and to the sides of the Achilles tendon insertion may cause problems with friction against the counter of the shoe (blisters, calluses, difficulty in shoe fitting). Where the exostosis is restricted to the lateral side it is known as a Haglund deformity
Cuneiform exostosis An exostosis formed on the dorsum of the foot by arthritic lipping at the margins of the joint between the first metatarsal and medial cuneiform may cause similar difficulties.
- Fifth metatarsal head Prominence of the fifth metatarsal head (bunionette or tailor’s bunion) may occur and is often associated with a varus deformity of the fifth toe (quinti varus).
All the above conditions are treated by local excision of the prominence.
- Fifth metatarsal base The base of the fifth metatarsal is sometimes enlarged and unduly prominent, especially in the narrow foot; it may sometimes cause pressure against the shoe, but surgical treatment is seldom required