High Prevalence of Foot Insufficiency Fractures in Patients With Inflammatory Rheumatic Musculoskeletal Diseases

To assess the prevalence of foot insufficiency fractures (IF) in patients with rheumatic musculoskeletal disease (RMD) with foot pain.In a retrospective design, 1752 magnetic resonance imaging (MRI) scans of consecutive patients presenting with foot pain in 2 time periods between 2016 and 2018 were evaluated. The group with IF was matched with controls with foot pain without IF. Bone mineral density (BMD) was assessed by dual-energy x-ray absorptiometry. Multivariate analyses were performed.A total of 1145 MRI scans of patients (median age 59 yrs, 82.9% female) with an inflammatory (65.4%) and of 607 with no inflammatory (34.6%) RMD (median age 58 yrs, 80.8% female) were available. Most patients had rheumatoid arthritis (RA; 42.2%), and others had psoriatic arthritis (22.4%), axial spondyloarthritis (11.1%), or connective tissue disease (CTD; 7.6%). Foot IF were found in 129 MRI scans of patients (7.5%). There was no difference between time periods. The prevalence of IF was highest in CTD (23%) and RA (11.4%). More patients with an inflammatory than a noninflammatory RMD had IF (9.1% vs 4.1%, respectively; P < 0.001). Using conventional radiography, IF were only detected in 25%. Low BMD and a history of fractures were more frequent in patients with IF than without (42.6% vs 16.2% and 34.9% vs 8.6%, respectively; P < 0.001).A high prevalence of foot fractures was found in MRI scans of patients with RMD, many without osteoporosis. MRI was more sensitive than radiographs to detect IF.