A clinical evaluation of the total first metatarsophalangeal joint prosthesis: the use of footprints in assessing foot contact.

The use of footprints in evaluating surgical results is most significant to the physician. This clinical investigation consisted of patients whose surgical correction of severe hallux valgus included the use of the Swanson-total great toe hinged prosthesis. The resulting failure of weightbearing by the great toe pulp postoperatively were found to be associated with excessive weightbearing by the lesser metatarsal heads, evidenced by discrete keratomas, a relative lesser metatarsalgia, and footprinting analysis. In conclusion, we believe that there is a definite relationship between the lack of weightbearing under the first ray and the instability of the first metatarsophalangeal musculoligamentous structures. This was found to be influenced by metatarsal protusion and first metatarsophalangeal joint range of motion. The possibility also exists that the intrinsic property of silicone played a role in failure of great toe weight-bearing. It is our belief that the Swanson-total is truly and mainly a joint spacer that relieves pain associated with first metatarsophalangeal joint arthrosis. The possibility exists that when using the Swanson-total with a short first metatarsal protrusion it may be necessary to perform shortening osteotomies on the appropriate lesser metatarsals. This redesigning of the metatarsal parabola could restore a normal forefoot weight-bearing pattern and minimize postoperative complications. Further research on this matter is in the planning stages.