Presentation
Patient presented with history of trivial injury to foot.
Patient Data
Radiograph of left foot shows the presence of a distinct osseous structure within the fourth intermetatarsal space consistent with accessory metatarsal. The accessory bone along with fifth metatarsal is contributing to the formation of fifth metatarsophalangeal joint without any bony fusion. No visible external deformity was present.
Note is made of lack of distal interphalangeal joint with presence of only two phalanges in fifth toe.
Additional note is made of os peroneum.
No acute bony injury is seen.
Case Discussion
Polymetatarsia is an anomaly characterized by presence of additional one or more metatarsals. It can occur in association with polydactyly (supernumerary digit) or without polydactyly. Polymetatarsia without polydactyly is a rare variant 1 .They may be incidentally discovered on imaging done for other purposes, such as in this case. However, some patients can present with pain in foot. In such cases resection of the extra bone proves beneficial in pain relief.
Differential diagnosis includes os intermetatarseum ossicle. The presence of growth plate favors the former 2 .
Case also contributed by Tanya Sehgal.