Radiographic factors associated with painful callosities after forefoot surgery in patients with rheumatoid arthritis.

Objectives: Operative procedures for rheumatoid forefoot deformities have gradually changed from arthrodesis or resection arthroplasty to joint-preserving surgery. Although joint-preserving arthroplasty has yielded good outcomes, painful plantar callosities may occur post-operatively. This study aimed to reveal the radiographic factors associated with painful callosities after joint-preserving surgery for forefoot deformities in patients with rheumatoid arthritis (RA).

Methods: We retrospectively evaluated 166 feet in 133 patients with RA who underwent forefoot joint-preserving arthroplasty, including proximal rotational closing-wedge osteotomies of the first metatarsal, between January 2012 and December 2015. Logistic regression analysis was performed with the objective variable set as the presence/absence of painful plantar callosities at the final observation and the explanatory variables set as several radiographic factors, including post-operative relative first metatarsal length (RML), amount of dorsal dislocation of the fifth metatarsal (5DD), and arc failure of the lesser toes.

Results: At the final follow-up, 42 of the 166 feet (25.3%) had painful callosities under the metatarsal heads post-operatively. Logistic regression analysis showed that the RML, 5DD, and lesser toes' arc failure were significantly associated with painful callosities.

Conclusions: We identified that RML, 5DD, and arc failure of the lesser toes were associated with painful plantar callosities after the surgery.