SAT0705 Association between fracture sites in patients with a history of parental fracture

Abstract

Background: Fragility fractures (FF) are fractures due to low energy force. Factors predisposing to FF in the general population include reduced bone mineral density (BMD), and family history of osteoporosis. FF most commonly occur in the vertebrae, proximal femur, and distal radius. Studies have demonstrated increased risk of FF in patients with decreased BMD and parental history of FF, particularly hip fracture.1,2 Few data exist on the association between sites of fracture in patients with a history of parental fracture, especially whether they co-exist at several sites and if particular factors are associated with discrete sites. Objectives: We aimed to find the correlation between sites of FF in patients with a history of parental fracture, and identify and examine the clinical association with any clusters of fractures. Methods: 2094 patients with a history of parental FF and personal history of at least one FF, presenting for BMD estimation from their primary or secondary care practitioner, from 2006-2016, were included. Parameters recorded: height, weight, age at scan, average fat mass, site of fracture(s), smoking, alcohol, corticosteroid use, aromatase inhibitor use, Depo-Provera use, hormone replacement therapy (HRT), rheumatoid arthritis (RA), polymyalgia rheumatica (PMR), breast or prostate cancer, and coeliac disease. Factor analyses with polychoric correlation matrices were applied to determine association between fracture sites. Any associations with Eigenvalues of more than one were then examined using a logistic model to analyse the effect of the above risk factors. Results: Fracture sites with Eigenvalue of more than one (tibia/fibula, spine, ribs, pelvis) were compared to sites with least co-variability (humerus, forearm, femur). The two cohorts were significantly different in age; therefore, an age-adjusted model is reported below (table 1). Smoking, HRT, and increased age significantly impacted clustering of fractures in the tibia/fibula, spine, ribs, and pelvis, compared with clustering at the humerus, forearm, and femur. Conclusions: In this cohort of patients, there was overlap between all fracture sites, with significant clustering seen in fractures of the tibia/fibula, spine, ribs, and pelvis. After adjusting for age, predictors of fracture in this cluster were smoking, HRT and increased age. This indicates that risk factors for FF are different at different sites, and affects the association of fracture between sites. Further work validating this finding is currently underway.