Propionibacterium in a primary arthroplasty after a Latarjet procdure, seeing what you look for

Monday, July 28, 2014

Propionibacterium in a primary arthroplasty after a Latarjet procdure, seeing what you look for

A man is his early twenties presented with pain and stiffness in the shoulder after two prior instability procedures, the last being a Latarjet in 2012.

He had a primary hemiarthroplasty with removal of the screw, the head of which was rubbing on his humeral head. Because of the global loss of cartilage seen on his preoperative films, we obtained cultures before administering antibiotics.
At surgery there was no obvious evidence of infection. The humeral head showed global loss of cartilage as shown here.
His postoperative films are shown here.

After surgery he was started on the ‘yellow’ antibiotic protocol. Range of motion exercises were started on day one and he had 150 degrees of motion on discharge two days later.

Five days after surgery, the cultures grew out coagulase negative staph in one specimen and Propionibacterium in three (capsule, humeral head #1 and humeral head #2). At that time a PICC line was plaeced and he was converted to the ‘red’ antibiotic protocol.

Comment: It would have been easy to miss this infection. Our index of suspicion was heightened by the generalized destruction of the joint surface in contrast to the local destruction that would be expected from contact of the humeral head with the screw.