Anatomically based classification of medial clavicle fractures.

Medial clavicle fractures represent less than 5% of all clavicle injuries. The purpose of this study was to evaluate reliability of a new anatomically based (AB) classification system compared to other classification systems and to evaluate the clinical outcome of nonoperative treated fractures. 55 acute medial clavicle fractures (55 patients) were 3D reconstructed and evaluated using the Edinburgh (ED), Throckmorton (TR) and new AB classification. The AB classification classified the fracture as medial (Type 1) or lateral (Type 2) to the costoclavicular ligament and no or minimal displaced (Type A) or displaced (Type B). Next, a consecutive retrospective clinical evaluation of 38 of these patients was performed using the Oxford Shoulder and Constant Score. An anatomically based classification shows the highest inter- and intra-observer reliability. In case the fracture line originate medial to the costoclavicular ligament and is displaced the Constant and Oxford scores are significantly less.