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.