Saturday, July 12, 2014

Propionibacterium - the 'stealth' organism in shoulder joint replacement arthroplasty. When does the worry stop?

Substantial cultures of Propionibacterium can be found in apparently aseptic shoulders revised three years or more after the index arthroplasty

Revisions of apparently “aseptic” shoulder arthroplasties are not infrequently culture positive for Propionibacterium, organisms that may be introduced at the time of the index surgery when the dermal sebaceous glands are transected. 

We sought to answer the question, "Do surgeons performing revision shoulder arthroplasty years after the index procedure need to be concerned about the persistence of Propionibacterium?"

We reviewed our records of 148 revision arthroplasties performed between July 2008 and June 2013 for problems of stiffness, pain or component loosening.  We found 14 cases in which the revision was performed at least 3 years after the index procedure and at which intraoperative cultures were strongly positive for Propionibacterium. All 14 patients were male. None of these cases had clinically apparent evidence of infection. Importantly these 14 cases did not come to revision until 8 ± 4 years after the original arthroplasty. A total of 109 specimens were obtained, 84 of which were positive.

Comment:  It is now recognized that shoulder arthroplasties revised for the mechanical problems of loosening or stiffness can be substantially culture positive for Propionibacterium, even if the revision is performed many years after the index procedure. Therefore, even in shoulder arthroplasties revised for mechanical problems years after the index procedures, surgeons should consider submitting multiple deep specimens for specific Propionibacterium culture. In the presence of persistent Propionibacterium, surgeons should consider the need for directed surgical and medical treatment in their management of a failed arthroplasty.