Shoulder arthroplasty. Indications, contraindications and complications.

Prosthetic substitution of the glenohumeral joint, begun at the end of the last century, has developed greatly in recent years. Today the most widely used shoulder prostheses are defined as "modular" because of their extensive adaptability. The capacity to adapt to anatomic variations must be incorporated within their structure, and normal articular biomechanics must be respected. The choice of prosthesis must be based on the condition of the joint surfaces, on the anatomic and functional condition of the rotator cuff. So endoprosthesis of the shoulder is indicated for avascular necrosis of the head of the humerus, fractures and pseudoarthrosis of the extreme proximal end of the humerus, arthropathy following rotator cuff rupture. Total shoulder prosthetization is indicated for glenohumeral osteoarthritis, rheumatoid arthritis and outcomes of endoprosthesis. The principal contraindications for shoulder replacement include an infection in progress, Charcot's arthropathy and severe neurological pathologies. The complications of shoulder prostheses include infection, dislocation, loosening of a component, periprosthetic humeral and glenoid fractures, nerve injuries, fractures of a prosthetic component and ectopic ossification. At present prosthetic substitution of the glenohumeral joint offers good results. Indispensable conditions for these results include anatomic and functional integrity of the musculature, good bone quality, correct positioning of the prosthetic components and a proper rehabilitation program.

Isolated avulsion fracture of the lesser tuberosity of the humerus. Report of two cases.

We describe two cases of isolated avulsion fracture of the lesser tuberosity: this is an extremely rare pathology, and to our knowledge only 34 cases have been reported in the literature. In the present cases, standard radiography and computed tomography clearly evidenced the detached bone fragments. As the patients refused surgical reduction, they were treated conservatively. Outcomes were successful, and three months after injury both of them returned to normal activity with only slight limitation in external rotation. At their check-up six-months after injury the patients continued to carry on normal activity, in both cases their limitation in external rotation had decreased even further. Both patients were pain-free and satisfied with their treatment outcome.