Bone mineral density of the lumbar spine in a South African population using Computed Tomography scans

Bone mineral density (BMD) is a potentially population specific material property influencing Orthopaedic surgery. This study aimed to determine BMD values of healthy/normal lumbar spines to further define and investigate possible population variation/s. 82 CT-scans from Steve Biko Academic Hospital (Pretoria) were used, of which 36 were females (22 black; 14 white) and 46 males (32 black; 12 white). Lumbar vertebrae (L1-L5) were analysed at cortical regions: the superior (SEP) and inferior endplates (IEP) and the anterior (AB) and posterior borders (PB) as well as medullary regions: 3 regions of interest (ROIs). Ranges (in Hounsfield Units) were: Cortical: black males, 522.68-541.11; white males, 479.51-507.89; black females, 496.91-520.04; white females, 484.50-517.08. Medullary: black males, 230.38-236.50; white males, 201.18-210.91; black females, 211.04-222.60; white females, 195.24-208.72. IEP was denser than SEP, and PB denser than AB for most measurements. ROI2 was the lowest and ROI3 the highest for most measurements. Black males surpassed black females, but the opposite was seen for several white cortical measurements. Overall, black individuals showed higher BMD values than white individuals. Awareness of differences in South African populations could aid in allocating interventions suitable for specific patients.