Investigation of the relationship between different cortical thickness measurements obtained from the proximal humerus and local and whole-body bone mineral density values

Investigation of the Relationship Between Different Cortical Thickness Measurements Obtained from the Proximal Humerus and Local and Whole-Body Bone Mineral Density Values The aim of this study is to investigate the relationship between various cortical thickness measurements obtained from the proximal humerus and both local and whole-body bone mineral density (BMD) values. By comparing these measurements with the gold standard Dual-Energy X-ray Absorptiometry (DEXA) results, the study seeks to identify accurate methods for diagnosing and assessing the severity of osteoporosis. This prospective clinical study included 100 participants aged between 65 and 80 years. Participants underwent DEXA scans and dual-energy computed tomography (Dual CT) for BMD assessment. Cortical thickness measurements were obtained from anteroposterior shoulder radiographs of the dominant extremity. The study includes measurements of the medial cortical ratio (MCR), deltoid tuberosity index (DTI), and linear cortical index (LCI). Statistical analyses were conducted using SPSS v25.0 to examine the relationships between cortical measurements and DEXA results. T-scores obtained from whole-body BMD values were statistically significantly correlated with BMD values obtained from the proximal humerus. There are significant positive correlations between the indices obtained from cortical thickness measurements of the proximal humerus and the BMD values derived from DEXA. In direct radiographic measurements, the deltoid tuberosity index (DTI) is a strong predictor for proximal humerus and proximal femur BMD values, while in Dual CT measurements, both DTI and LCI are strong predictors. According to the results obtained from Dual CT, osteoporosis-related fatty infiltration of the humeral head shows heterogeneity, with the most significant infiltration occurring at the greater and lesser tubercles. If the local BMD of the proximal humerus is to be predicted using direct radiographs or CT, DTI should be preferred due to its simplicity and reliability, as well as its minimal impact on fracture points. Due to the presence of different BMD values in different anatomical locations of the humeral head at the same time, there is a need for location-specific cortical thickness and BMD measurements.