Rate of Development of Hallucal Interphalangeal Degenerative Joint Disease After First Metatarsophalangeal Joint Arthrodesis: A Retrospective Radiographic Analysis.

The development of hallux interphalangeal joint (IPJ) arthritis after an arthrodesis of the first metatarsophalangeal joint has been established in the literature. However, the significance has not been well reported. A retrospective, radiographic review of patients who had undergone a first metatarsophalangeal joint arthrodesis was performed. The Coughlin classification for degree of arthritic degeneration, hallux abductus angle, and hallux interphalangeus angle were measured in 107 radiographs of 103 patients preoperatively and postoperatively. Postoperative angles were measured immediately following surgery at approximately 6 weeks, 3 months, 6 months, 12 months, and 24 months. We found that the hallux abductus angle had decreased in the patients postoperatively; however, the hallux abductus interphalangeus angle increased on average after first metatarsophalangeal fusion. The majority of patients started with a Coughlin classification I of the hallux IPJ, which remained unchanged over the postoperative period, with no statistically significant difference in IPJ degeneration in the patients with or without fusion of the first metatarsophalangeal joint. In addition, no patients had a symptomatic hallux IPJ postoperatively within our limited study period. Further prospective studies would be beneficial with longer follow-up times to assess IPJ degeneration following first metatarsophalangeal joint fusions. Level III: Retrospective, comparative study.