UW Shoulder and Elbow Academy: Failed total shoulder, difficult revision

One year after a total shoulder arthroplasty, this patient presented with a draining right shoulder wound, a red arm, and a painful shoulder

and these x-rays showing glenoid osteolysis, a fractured hybrid fixation peg and stress shielding of the upper humerus with a bone-ingrowth press fit humeral stem.

At surgery, the sinus track was excised along with chronic inflammatory tissue. Frozen sections were negative for white cells.

The retrieved glenoid showed a fractured peg

The portion of the peg remaining in the glenoid was removed with a trephine.

Removal of the humeral component was difficult because of the tight diaphysial fit and the fragile osteopenic metaphyseal bone.

A cement spacer was inserted because of the suspicion of infection.

The patient will be placed on the 'red' protocol of IV antibiotics until the cultures are finalize.

This case demonstrates (1) the ever present risk of infection in shoulder arthroplasty, (2) the susceptibility of fatigue fracture of a metal post, (3) the problems created by a tight press-fit bone ingrowth stem should prosthesis removal become necessary.

The potential for fatigue fracture of a hybrid post has been shown in a recent article

Five-year minimum clinical and radiographic outcomes of total shoulder arthroplasty using a hybrid glenoid component with a central porous titanium post.

Here is a radiograph from that article.