Fragility Fractures in Patients with Psoriatic Arthritis

Psoriatic arthritis (PsA) can have peculiar effects on bone, including mechanisms of bone loss such as erosions, but also of bone formation, such as ankylosis or periostitis. The aim of the present study was to describe the prevalence of fractures in patients with PsA as compared to healthy controls and to investigate determinants of fractures among cases. For both cases and controls, radiographs were read to identify vertebral fractures (VF), and the presence of femoral neck or other nonvertebral fractures was obtained from patients' medical history. The prevalence of fragility fractures on radiographic readings did not differ between cases and controls. The number of subjects showing a VF was 33 (36%) among PsA patients and 36 (36%) among controls, with a prevalence of severe VF of 8% among cases and 4% among controls. Controlling for covariates in a logistic model, the only variables showing a significant correlation with the presence of nonvertebral fractures (NVF) were disease duration (p=0.02), age (p=0.03), and bone mineral density at femoral neck (inverse correlation, p=0.04). Fractures should be carefully considered when evaluating the global picture of the patient with PsA for their contribution to the "fragility" profile.