Sunday, April 27, 2014

Stress fractures after reverse shoulder replacement

Stress fractures after reverse shoulder replacement is a problem that has to be recognized and accurately diagnosed early. The reported rate is 3-5% and the factors leading to this complication are (1) Over-lengthening of the arm (2) Advanced age at the time of surgery or osteopenia (3) Usually there is minor accident involved. Most of these fracture occur at the acromion while it is not uncommon to see them at the scapula. It is a problem that if left untreated can lead to displacement of the acromion, loss of tension of the deltoid and poor outcome. Usually the patient will stop using the shoulder and will present with "global" or posterior shoulder pain without any obvious explanation. Some surgeons do immobilize with shoulder in a sling for a period of 6 weeks if the X-rays are negative for a fracture. In my opinion, advanced imaging in the form of CT scan is required to see where the fracture is located. The value of the CT lies on the type of approach that will be selected for the treatment of this complication. The following case (one of my patients) demonstrates the workup of this condition in the setting of negative X rays. The patient regained all of his motion after a 6 week period of strict immobilization in a sling and the fracture did not displace. In addition, please note the position and length of the central locking baseplate screw of this system (glenoid side).







CT 3D reconstruction of the shoulder better demonstrates the acromial stress fracture (reconstruction performed with Osirix software)