Amer Al-Ani, Tommy Cederholm, Maria Saaf, Gustaf Neander, D Richard Blomfeldt, Wilhelmina Ekstrom and Margareta Hedstrom
Karolinska Institute, Sweden
Posters & Accepted Abstracts: Orthop Muscular Syst
Background: Reduced bone mineral density (BMD) together with muscle wasting and dysfunction, i.e. sarcopenia, emerge as risk factors for hip fracture. The aim of this study was to examine body composition, BMD and their relationship to trauma mechanisms in young and middle-aged patients with femoral neck fracture. Materials & Methods: In this study 185 patients with femoral neck fracture aged 20-69 were included. BMD, body composition, including fat-free mass index (FFMI) were determined by dual-X-ray absorptiometry (DXA) and trauma mechanisms were registered. Results: 90% of the whole study population had a femoral neck BMD below the mean age. In the young patients (<50 years) 27% had a Z-score of BMD â�?¤ -2 SD. More than half of the middle-aged patients (50-69 years) had osteopenia, i.e. T-score -1 to -2.5, and 35% had osteoporosis, i.e. T-score<-2.5, at the femoral neck. Patients with low-energy trauma, sport injury or high-energy trauma had a median standardized BMD of 0.702, 0.740 vs. 0.803 g/cm2 (P=0.03), and a median FFMI 15.9, 17.7 vs. 17.5 kg/m2 (P<0.001), respectively. FFMI<10th percentile of an age- and gender matched reference population was observed in one third. Conclusions: A majority had low BMD at the femoral neck and one third had reduced FFMI (i.e. sarcopenia). Patients with fracture following low-energy trauma had significantly lower femoral neck BMD and FFMI than patients with other trauma mechanisms. DXA examination of both BMD and body composition could be of value especially in those with low energy trauma.