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Abstract
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The preservation of both life and limb is a sacred tenet of the medical profession. More dramatic is the preservation of life. And less dramatic is the preservation of limb. Much of the effort generated in the past decades toward the preservation of life, particularly with automotive safety, has proved more or less successful. One is now frequently confronted with a survivor of a head-on road crash handicapped by disturbing limb disabilities, a problem which has received meager attention in the past. Such disabilities are disturbing not only from the aspect of severity and residual disability, but just how such a crash can produce such an injury. The purpose of this paper is to describe a certain type of foot injury which occurs with remarkable similarity in head-on collisions.
The specific foot injury involves disruption (fracture-dislocation) of the tarso-metatarsal joint complex. The tarso-metatarsal joint represents the anatomical connection of the forefoot to the mid-foot. Held securely by ligaments and reinforced on the plantar aspect by the muscles of the arch of the foot, this joint complex is nevertheless vulnerable to certain forces applied to the foot. Two anatomical features bear considerable importance, however. Firstly the unique anatomical arrangement of the base of the second metatarsal -that is, it is firmly locked in a mortise formed by all the cuneiform bones. Because the base of this metatarsal is not in the same curvilinear plane as the remainder of the tarso-metatarsal joints it is easily fractured, and, in fact, becomes the sentinel injury of such a disruption. Secondly, the tarso-metatarsal joint complex is poorly reinforced dorsally by soft tissue structures, and, forming part of a convex arch, is vulnerable on the dorsal aspect. Should such forces be applied to the foot to disrupt the tarso-metatarsal joint, a specific injury pattern occurs including any or all of the following: a)fracture of the base of the second metatarsal; b)fracture of the cuboid; and c)fracture of necks, shafts, or bases of the metatarsals.
We present 30 cases of tarso-metatarsal joint disruptions. All of these cases occurred in head-on auto collisions. With two exceptions, all patients were occupants of the front seat. It would appear that such an injury may occur when the foot is directed forward into the sloping toe-pan or the firewall at time of impact. Although such an injury may have minor status relative to more serious injuries to head, chest, or abdomen, late results of this injury may involve major residual disability. |