Preoperative radiographic and clinical factors associated with postoperative floating of the lesser toes after resection arthroplasty for rheumatoid forefoot deformity

BACKGROUND: This study aimed to clarify the characteristics associated with postoperative floating of the lesser toes, especially focusing on the medial and lateral lessor toes, after arthrodesis of the first metatarsophalangeal joint and resection arthroplasty of the lessor toes in rheumatoid forefoot deformity. METHODS: Fourty-seven feet of 43 people who underwent resection arthroplasty of the metatarsal head of the lesser toes for rheumatoid arthritis of the metatarsophalangeal joints were included. We retrospectively evaluated the preoperative radiographic findings and clinical characteristics of the patients, and the occurrence of postoperative floating of the lesser toes. The mean duration of follow-up was 36.5 (range 12 to 114) months. RESULTS: Preoperative dislocation grades of the second and third toes that demonstrated postoperative floating were significantly higher than those of toes that did not experience postoperative floating. The hallux valgus deformity before surgery was significantly more severe in toes with postoperative floating of the second and third lessor toes than those with no floating (p < 0.05). In addition, the Japanese Society for Surgery of the Foot (JSSF) hallux scale scores before surgery in toes with postoperative floating of the fourth and fifth lessor toes were significantly worse than those in non-dislocating toes (p < 0.05). CONCLUSIONS: The preoperative condition of the first metatarsophalangeal joint, including hallux valgus deformity, pain, range of motion, activity of daily living, and function is significantly different between postoperative floating of the lesser toes and non-floating of them after resection arthroplasty for rheumatoid forefoot deformity.