A report of a 7‐toed foot

Abstract

The right foot of a 65-year old female specimen from the gross anatomy laboratory had seven toes. A study by x-ray films and dissection showed that two extra toes were inserted within the normal limits of the foot between the hallux and axial digits.The phalangeal complement of the seven toes was complete but the two extra toes were borne on the bicapitate distal end of a single extra metatarsal. The medial (first) cuneiform tarsal was tripartite. The flexor musculature was for all practical purposes complete but the extensor musculature absent.Polydactylism has been found to occur rather frequently in human populations. The various conditions of polydactylism may be grouped into three general categories as follows:(1) as supernumerary digits outside of the normal limits of the foot or hand, such as the prehallux and postminimus;(2) as longitudinal "splitting" of existing digits; and, ( 3 ) as extra digits inserted within the normal limits of the foot or hand.During the '61-'62 school year a 65-year old female specimen in the gross anatomy laboratory was found to exhibit a case of the third type of polydactylism. Two extra toes were found to be inserted between the first (hallux) and the second (axial) digits. The foot was removed at the talotibular joint and carefully studied by means of x-ray films and dissection. My sincere thanks and appreciation are herewith extended to JosC E. Polanco, M.D. of Caguas, Puerto Rico for his cooperation in providing the necessary x-ray films for this study. Detailed descriptionThe right foot of this 65-year old female had seven toes (see fig. 1 ) while the left foot had the usual five. The second toe was bound along its medial edge proximally to the lateral surface of the hallux. All the other toes were freely separate.Skeleton. The seven digits had their normal number of phalanges, three for each toe with two for the hallux. The phalanges of the "third" toe were thicker than those of the "second."The intermetatarsophalangeal bursae were present between all of the metatarsophalangeal areas. That between the "third toe and the axial digit however was displaced because of the foreshortened second metatarsal. This bursa was located between the distal lateral surface of the proximal phalanx of the "third digit and the proximal medial area of the axial digit. The bursa between the "second and "third" toes was not very pronounced.Six metatarsal bones were present, the second bearing the two additional toes. This second metatarsal however was bicapitate dorso-ventrally at each end. The "second toe was borne on the plantar distal head while the "third" toe was borne on the dorsal distal head. The first and second metatarsals articulated with the medial (first) cuneiform tarsal, the third and fourth with the intermediate (second) and lateral (third) cuneiform tarsals respectively, while the fifth and sixth articulated with the cuboid tarsal.The medial cuneiform tarsal in this specimen was actually a complex of three separate bones extending longitudinally and parallel from the n...

A case of eight-toed foot

“…Supernumerary digits have been classified into the human. It has been grouped into three categories by Nelson (1963):…”