Clinical features and risk factors for Baker's cyst in patients with rheumatoid arthritis

Objectives Baker's cyst (BC) is a complex complication of rheumatoid arthritis (RA), with a poor prognosis. This paper aimed to analyse the clinical features and risk factors for BC in patients with RA to assist clinicians in early warning and appropriate action. Methods The clinical features of the hospitalized RA patients with knee affected were analysed retrospectively. The R software was used for the statistical analysis, while logistic regression analyses were used to determine independent risk factors. Results A total of 367 RA patients with knee affected were studied, and BC was diagnosed in 15.3% of them. The BC group exhibited a higher proportion of knee-only affected than the non-BC group (P < .05), while the attributes linked to disease activity exhibited no disparity. Logistic regression analyses selected two independent risk factors for BC: knee-only affected and anaemia. A total of 26.8% of patients with BC developed rupture, exhibiting a higher proportion of knee-only affected (P < .05), compared to those unruptured. Conclusions The occurrence and rupture of BC in RA patients were significantly related to local inflammation, but not to systemic one. Incorporating local treatment may be a more advantageous option compared to solely relying on systemic therapy.