Predictors for orthopaedic surgery in patients with rheumatoid arthritis: results from a retrospective cohort study of 1010 patients diagnosed from 1972 to 2009 and followed up until 2015

Objectives: To investigate how patient characteristics, time of diagnosis, and treatment affect the need for orthopaedic surgery in patients with rheumatoid arthritis (RA).Method: We reviewed the medical history of 1544 patients diagnosed with RA at Haukeland University Hospital in Bergen, Norway, from 1972 to 2009, of whom 1010 (mean age 57years, 69% women) were included in the present study. Relevant orthopaedic procedures were obtained from the Norwegian Arthoplasty Register and the hospital's administrative patient records. In total, 693 procedures (joint synovectomies 22%, arthrodeses 21%, prostheses 41%, and forefoot procedures 12%) were performed in 315 patients. Survival analyses were completed to evaluate the impact of different factors such as age, gender, radiographic changes, and year of diagnosis, on the risk of undergoing surgery.Results: Patients diagnosed in 1972-1985 and 1986-1998 had a relative risk of undergoing surgery of 2.4 and 2.2 (p<0.001), respectively, compared to patients diagnosed in 1999-2009. Radiographic changes at diagnosis and female gender were also significant risk factors. Anti-rheumatic medication was significantly different in the three time periods.Conclusion: Patients with a diagnosis in the early years had a greatly increased risk of having orthopaedic surgery performed. This is probably due to the year of diagnosis being a proxy for the type and intensity of medical treatment.