Endocrine Abstracts

Bone mass, macrostructure and lean mass are being identified as main contributors of strength of upper femur. The purpose of this study has been to assess the role of the cortical and trabecular bone as well as muscle mass in the hip fracture production. We used a new DXA application which allow 3D bone volume reconstruction from standard 2D DXA scans, providing a three dimensional approach of the femoral shape and bone density spatial distribution and measurement cortical thickness. The purpose of this study was to analyze these measurements in a cohort of elderly patients suffering a recent hip fracture.

Methods: A prospective study was carried out to collect scans from 96 patients of both sexes, older of 75 years, who have suffered a hip fracture indoor in a shorter interval of 2 weeks. None of the patients had osteoporotic fracture history at baseline. 3D-DXA technology in an early version (Galgo Medical S.L; Barcelona, Spain) was used to obtain patient-specific models from the 2D-DXA scans performed in the opposite femur (iDXA model GE Healthcare). The 3D-DXA algorithm made the registration of a 3D appearance model incorporating statistical information about the femoral shape and density onto the 2D DXA image. From the resulting patient-specific models the volumetric BMD can be automatically quantified as well as the volume (for trabecular and cortical regions) and cortical thickness distribution. Also, a total body scan was performed in these patients for body composition analysis purpose. The parameters were compared with reference values obtained on age and sex matched healthy volunteers and also on young people of same sex.

Results: A 47.1% of these patients were classified as osteoporotic using the WHO criteria. The femur of the patients suffering hip fracture show a significant less vBMD and BMC in cortical and trabecular bone (P>0,001). The average cortical thickness was also lower for fracture group (1.49 mm) than for sex and age-matched references (1.63 mm, P<0.001). This difference was bigger (26%) at the antero-superior radiant of femoral neck. The limb lean mass had a good correlation with all the bone parameters (r2: 0.218–0.375). Trabecular bone parameters (vBMD, BMC) were the most deviated from reference values.

Conclusion: Both trabecular as well as cortical bone assessed by 3D-DXA are decreased in patients suffering hip fracture.