A Rare Intermetatarsal Coalition With Rigid Fifth Metatarsal Deformity and Symptomatic Plantar Lesion

Abstract Coalition or synostosis of the foot is a relatively uncommon abnormality. Some cases of synostosis of the foot, primarily involving the midfoot and hindfoot, have been reported. However, intermetatarsal coalition is extremely rare, with only a small number of cases reported. We report a case of a unilateral, congenital metatarsal coalition between the fourth and fifth metatarsal bones in a 27-year-old female. She had initially been referred because of a symptomatic plantar lesion under the fifth metatarsal head. Surgery consisted of separating the affected metatarsals, combined with a proximal osteotomy, which proved successful in establishing pain-free and more natural weightbearing.