Purpose: Distal clavicle marrow edema: frequency, MRI in the early stage and macroscopic correlation to the bone marrow distribution and to evaluate frequency and diagnostic criteria of a posttraumatic clavicula disorder with an edema pattern on MRI. An additional macroscopic study of the clavicle should elucidate anatomic peculiarities which could explain the reaction of the distal clavicle.
Material and methods: 285 MRI of traumatized patients were analyzed for edema pattern of the distal clavicle. Pattern A edema within the clavicle and the acromion was distinguished from pattern B edema within the clavicle only. Dissection in 20 cadavers should reveal vascular peculiarities and the bone marrow distribution within clavicle and acromion or vascular peculiarities.
Results: In 38 patients (13,3%) we found edema within the distal clavicle. Pattern A was found in 28 (9,8%) and pattern B in 10 patients (3,5%). Pattern A was usually associated with swelling of the AC joint (27 out of 28). Other injuries were not evident. 18 cadavers showed hematopoietic marrow within the distal clavicle and fatty marrow within the acromion.
Conclusion: The distal clavicle can frequently react with edema pattern after trauma without evidence for another injury. Distinguish in cases with and cases without synovitis of the AC joint could have impact on therapy. A peculiar vascular supply of the distal clavicle could not be found.