Os Intermetatarseum and Polymetatarsia Without Polydactyly: A Case Report

Abstract

Nontraumatic bony abnormalities of the foot occur at different rates, according to the literature. However, it is uncommon to see rare variations presenting together in one patient. This article discusses two less common anomalies: fused os intermetatarseum and polymetatarsia without polydactyly. Etiology, symptomology, diagnosis, and treatment are reviewed, in addition to the relationship of the two conditions to each other. We then discuss a case where both anomalies are present at the same time in a 17-year-old patient.

Polymetatarsia of the Foot without Polydactyly

“…All forms were 4B type 9 and arose from the lateral aspect of the fourth metatarsal. There are 3 main variants: (1) a standalone type where the supernumerary bone does not communicate with the fifth metatarsal 10 , (2) a conjoined type where the supernumerary bone fuses distally with the fifth metatarsal head to form a distal common metatarsal head complex 11,14 , and (3) a dominant type where the supernumerary metatarsal articulates primarily with fifth phalanx 12 (Fig. 8).…”