Do biologic drugs affect the need for and outcome of joint replacements in patients with rheumatoid arthritis? A register-based study

Objectives: The aim was to study the incidence of joint replacements among biologic drug and disease-modifying anti-rheumatic drug (DMARD) users as well as to investigate the plausible effect of biologic treatment on survival of prostheses in patients with Rheumatoid arthritis (RA).

Methods: The study population comprised 2 cohorts of patients [Register of biologic treatment in Finland (ROB-FIN) and the Central Finland RA database] from 1999 to 2010. Records of joint replacements performed in the study population between 1980 and 2010 were retrieved from the Finnish Arthroplasty Register. Propensity score matching was used to equalize patient characteristics between biologics and DMARD users. The incidence rates of primary and revision operations were compared between the 2 treatment groups. Kaplan-Meier survival analysis was used to analyze prosthesis survival.

Results: Of the 2102 biologics and 2710 DMARD users identified from the registries, 1587 were included in both groups after the matching. Median follow-up times were 3.1 and 8.0 years, respectively. There were more primary operations per 100 patient years in the biologics (3.89, CI 95% 3.41-4.41) vs. DMARD (2.63, 2.35-2.94) group but slightly fewer revisions (0.65, 0.46-0.88 vs. 0.83, 0.68-1.01). Biologics users were more likely to receive a joint replacement to small joints (p < 0.001). The survival of the prostheses installed during or prior to follow-up was similar in both treatment groups.

Conclusions: The use of biologic drugs did not reduce the need for joint replacement surgery in patients with a similar on-medication disease activity. Despite possibly lower rate of revisions among biologic users, the durability of prostheses was not improved.