Purpose: To evaluate the assumption that reaming is the main reason for problems of shoulder function (pain – restricted range of motion) after antegrade intramedullary nailing of humerus (unless impingement of fixation material on the rotator cuff or acromion occurs).

Materials – Methods: From January 1999 until March 2003 55 patients underwent unreamed antegrade intra-medullary nailing for treatment of recent fractures of the humeral shaft. Two different intramedullary nailing systems were used, that do not protrude from the humeral shaft and that do not require reaming for insertion. Patients with concomitant problems or complications that could affect the final functional result were excluded from the study (e.g. multiple injuries, brachial plexus lesions, etc.). The remaining 32 patients were examined for postoperative pain and functional problems in the shoulder joint.

Results: No patient complained of persistent shoulder pain. Range of motion was found comparable to that of the other shoulder.

Conclusions: Reaming seems to exert a harmful influence on the rotator cuff, due to direct injury caused by the reamers as they are inserted and withdrawn from the humeral head. Furthermore it is possible that bone reaming products, accumulating under the rotator cuff, contribute to the persistence of pain and loss of motion.