関節リウマチ前足部変形に対する足趾形成術の中期成績

抄録

Objective: The aim of this study is to investigate mid-term outcome of forefoot surgery for patients with rheumatoid arthritis (RA).

Methods: We investigated 39 feet in 28 patients who underwent forefoot surgery between January 2010 and December 2018. There were 34 feet in 24 women and 5 feet in 4 men. The average age at the time of surgery was 66 years old. They were followed for more than one year after surgery. Swanson implant arthroplasty or metatarsal correction osteotomy was performed for the big toe, and shortening oblique osteotomy (SOO) at the metatarsal neck was performed for the Ⅱ-Ⅴ toes. X-ray changes in the angle of hallux valgus (HVA), the angle between the first and second metatarsals (M1/2), and the angle between the first and fifth metatarsals (M1/5) were measured. Progression of painful hyperkeratosis and bunion, Japanese Society for Surgery of the Foot (JSSF) hallux and lessor toe scale, recurrence of deformity and bone union, complications, and patient satisfaction were also examined.

Results: Average HVA of 17 feet performed Swanson implant arthroplasty improved from 43.1 degrees to 22.3 degrees one month after surgery, but it increased slightly to 24.9 degrees one year after surgery. Also, average HVA of 15 feet performed metatarsal correction osteotomy improved from 47.6 degrees to 20.0 degrees one month after surgery, but it increased slightly to 26.4 degrees one year after surgery. Painful hyperkeratosis and bunion tended to disappear one month after surgery, and JSSF scale significantly improved at the final follow-up. One year after surgery, bone union rate of the big toe was 100%, while non-union occurred in 7.8% of the metatarsals which underwent SOO. Complications were one infection at the surgical site, one necrosis at the tip of the toe, and one infection around Swanson implant. Patient satisfaction at the final follow-up was high.

Conclusions: Forefoot surgery for patients with RA has some problems such as recurrence of deformity, non-union, and infection, however it is a useful procedure which eliminates pain at hyperkeratosis and bunion, and improves activities in daily living (ADL).