Background/Purpose:  Orthopedic surgery is used effectively in many patients with severe rheumatoid arthritis (RA). The aim of modern pharmacologic treatment is to prevent joint destruction and reduce the need for orthopedic surgery. Our purpose was to investigate trends in the incidence as well as predictors for such procedures in a population-based sample of patients with RA.

Methods:   The study was based on a dynamic cohort of all known patients from a defined geographical area with a clinical diagnosis of RA who fulfilled the 1987 American College of Rheumatology criteria for RA. A total of 2342 patients (68.7% women) were included. Questionnaires were sent to the RA patients in the register in 1997, 2002, 2005 and 2009(response rates 62-74 %) including visual analogue scales (VAS) for general health and pain and the health assessment questionnaire (HAQ). This register was linked to a regional health care register, which contains information on all inpatient and outpatient procedures in the area, to the national population register to add information on vitality and residential address, and to a regional register of patients with arthritis treated with biologics, which covers >90% of such patients in the region. The total follow-up was calculated for each calendar year from 1998 through 2011, and the annual incidence rate of orthopedic surgery procedures was estimated. The incidence rate for 1998-2001 was compared to those of 2002-2006 and 2007-2011. The impact of demographics and patient reported outcomes on the risk of future orthopedic surgery was analyzed using Cox proportional hazard models.

Results:   The incidence of all orthopedic surgery procedures during the whole study period was 82,3/1000 person-years (95 % confidence interval (CI) 78,7-86,0). The incidence of all procedures declined significantly over time, with a decrease also for large joint surgery and small joint surgery (hand, wrist, foot and ankle surgery), when studied separately (Table). There was a decline in hip surgery, but not in knee surgery (Table). The incidence of large joint surgery was reduced already in 2002-2006 compared to 1998-2001, whereas a decline in small joint surgery was apparent only in the final period (2007-2011).

Female sex was a predictor of orthopedic surgery [age adjusted hazard ratio (HR) 1.50; 95 % CI 1.23-1.83). Greater disability, measured by HAQ, was associated with a higher rate of orthopedic surgery (HR per standard deviation 1.37; 95 % CI 1.25-1.50 adjusted for age, sex and duration of RA), and similar, although weaker, associations were observed for VAS pain and VAS global.

Conclusion:   The overall incidence of orthopedic surgery declined over time which coincides with increasing use of more intensive pharmacological treatment including the use of biologics. The decrease in large joint surgery predated that of small joint surgery. Improved management may reduce the need for orthopedic interventions in patients with RA.