Arthroplasty rates and risk in familial Mediterranean fever patients: a large population-based study

Background: FMF is a genetic disorder characterized by recurrent episodes of fever and inflammation in various organs, including the joints. Traditionally, the arthritis of FMF has been considered relatively harmless. However, anecdotal evidence has suggested that it may contribute to long-term joint damage, which may necessitate surgical joint replacement. This study aimed to investigate the rates of arthroplasty among FMF patients and compare it with those of the general population. Methods: The study used the electronic database of the largest health-care organization in Israel to identify 9769 FMF patients diagnosed between 2000 and 2016. A similar number of age-, gender-, and residency-matched controls were also identified. The rates of arthroplasty were compared between the two groups. A logistic regression model predicting the need for arthroplasty within the FMF group was formed to identify potential risk factors. Results: Of the 9769 FMF patients, 114 (1.2%) underwent arthroplasty, compared with 64 (0.7%) of the control group [unadjusted odds ratio (OR) = 1.79, 95% CI 1.32–2.43; partially adjusted OR = 1.97, 95% CI 1.40–2.77; fully adjusted OR = 1.92, 95% CI 1.35–2.72]. Within the FMF cohort, those of North African origin had a significantly higher risk of arthroplasty (OR = 6.89, 95% CI 5.09–9.33; P < 0.001). Conclusion: FMF patients can experience long-term joint damage that may require arthroplasty. Although this complication is relatively uncommon in FMF patients, it occurs almost twice as frequently as compared with the general population. FMF patients of North African origin are at an even higher risk.