Relationship of callosities of the forefoot with foot deformity, Health Assessment Questionnaire Disability Index, and joint damage score in patients with rheumatoid arthritis.

We aimed to investigate the relationship of callosities of the forefoot with foot deformity, the Health Assessment Questionnaire Disability Index (HAQ-DI) and modified total Sharp score (TSS) in patients with rheumatoid arthritis (RA). A total of 202 patients and 404 feet were enrolled. We examined the prevalence of callosities. Clinical data included the HAQ-DI, TSS, hallux valgus angle (HVA), and calcaneal pitch angle (CPA). The analysis of factors associated with callosities of the forefoot was performed by comparing patients with and without callosities of the forefoot. The prevalence of callosities was 31.2% of all patients and 24.0% of all feet. The patients with callosities of the forefoot had significantly higher TSS of the foot. The presence of callosities affected the HAQ-DI walking score. HVA and CPA were identified as being associated with callosities of the forefoot. Analyzing from the cutoff values, the odds ratios of HVA, CPA, and HVA and (combined) CPA were 4.64, 1.73, and 2.99, respectively. Hallux valgus and flatfoot were related to callosities of the forefoot in RA. This study suggested that to prevent callosities of the forefoot, early diagnosis and foot care for hallux valgus and flatfoot are needed in daily practice.