Background Despite increased concern for injury during surgical reconstruction of the sternoclavicular joint, to our knowledge there are few studies detailing the vascular relationships adjacent to the joint. Questions/purposes We investigated sex differences in the following relationships for sternoclavicular joint reconstruction: (1) safe distance from the posterior surface of the medial clavicle's medial and lateral segments to the major vessels, (2) length of the first costal cartilage and safe distance from the first rib to the internal mammary artery, (3) minimum distance medial to the sternoclavicular joint for optimal hole placement, and (4) safe distance from the manubrium to the great vessels.Methods Fifty normal postcontrast CT scans of the chest were reviewed. Means, standard deviations, and 95% CI were calculated for each aforementioned measurement. A t-test was used to determine if a sex difference exists (p B 0.05).