Regional Osseous Morphology of the Medial Clavicle in Relation to the Impression for Costoclavicular Ligament: Considerations for Fixation, Resection and Reconstruction

Medial clavicle surgery is challenging because of the small medial fragment, limited bone stock, and the close proximity of vital mediastinal structures. The costoclavicular ligament is an important stabilizer of the sternoclavicular region, making its clavicular attachment relevant to fracture fixation, medial clavicle resection, and ligament reconstruction. This study aimed to characterize the morphology and topography of the impression for costoclavicular ligament and the regional osseous morphology of the medial clavicle. Seventy-one dry clavicles were examined. The dimensions and location of the impression for costoclavicular ligament were recorded. Anteroposterior (AP) and superoinferior (SI) osseous dimensions were measured at levels corresponding to its medial border, midpoint, and lateral border. The impression measured 21.86 ± 5.69 mm mediolaterally and 7.76 ± 2.24 mm anteroposteriorly. Its medial and lateral borders were located 8.36 ± 3.50 mm and 29.52 ± 6.21 mm from the most inferior point of the sternal articular surface, respectively. SI dimensions decreased from 18.19 ± 2.97 mm medially to 13.62 ± 2.25 mm centrally and 11.84 ± 2.11 mm laterally. Corresponding AP dimensions were 14.36 ± 3.84 mm, 11.79 ± 3.04 mm, and 10.57 ± 2.76 mm. All pairwise differences were significant (p<0.001). The medial clavicle demonstrates substantial topographic and level-specific osseous variability in relation to the impression for costoclavicular ligament. These quantitative data may provide anatomical reference values for medial clavicle fracture fixation, resection, and costoclavicular ligament repair or reconstruction.