Conversion of First Metatarsophalangeal Joint Arthrodesis to Interpositional Arthroplasty With Acellular Dermal Matrix for First Ray Ulceration: A Case Report.

The purpose of this study is to report the outcome of the conversion of a first metatarsophalangeal (MTP) joint arthrodesis to an interpositional arthroplasty with an acellular dermal matrix for a chronic nonhealing first ray wound. To our knowledge, this is the first case report converting a first ray arthrodesis to an interpositional arthroplasty to heal a chronic ulceration. A 78-year-old female developed a chronic neuropathic ulceration under the first metatarsal head and hallux after a first MTP joint arthrodesis. The patient failed local wound care and underwent gastrocnemius recession, hallux interphalangeal joint fusion, and an interpositional arthroplasty with the use of an acellular dermal matrix. Bone tunnels were placed proximal to the metatarsal neck, where absorbable sutures affixed to the dermal matrix were passed from plantar to dorsal, and the graft was secured to the reamed metatarsal head and associated capsule. Postoperative radiographs revealed improved alignment of the first MTP joint. Complete reepithelialization of the plantar ulceration occurred within 2 weeks postoperatively. At the 16-month follow-up, the patient was ambulating without restriction and continued to be free of first ray ulceration and infection. This case study details the use of an acellular dermal matrix in an interpositional arthroplasty to offload a chronic nonhealing ulceration secondary to elevated first ray pressure associated with first MTP joint arthrodesis. The goal of this treatment is to reduce pain, heal the ulceration, and prevent its recurrence.