Femoral cortical bone radiogrammetry data in a Portuguese reference skeletal collection

Radiogrammetric parameters of the femur were assessed in an adult sample (N=98) from the Coimbra Identified Skeletal Collection (Portugal). Anteroposterior radiographs of the midshaft area of the left femur of each individual were taken using a mammogram film with an exposure time of mAseg 80-50,exposure of Kv 30-35 and focal distance of 1.0 m. Maximum length of the femur, as defined by Martin and Saller (1957), was determined. Measurements of diaphysis total width (DTW) and medullary width (MW) were taken following a standardized guide. Radiogrammetry was used to establish cortical index (FEMCI) in the femoral mid-shaft. Diaphysis total width (DTW) and femoral cortical index (FEMCI) are significantly higher in males, while medullary width (MW) is not statistically different between sexes. The evaluation of femoral cortical bone reveals sex-specific trajectories of endosteal bone loss and periosteal apposition, stemming from sexual differences in the rate and pattern of bone loss, and in bone size. In females, endocortical bone loss rises with age, particularly in peri- and postmenopausal years, decelerating later in life. Concomitantly, accretion of bone in the subperiosteal surface persists throughout adulthood — partially offsetting bone fragility in women. Strength in the femoral mid-diaphysis appears to be preserved throughout most of the life course in both sexes.