Friday, September 30, 2016

Shoulder arthroplasty infections - they can present months or years after a post surgical 'honeymoon'

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. This report seeks to answer the question, Do surgeons performing revision shoulder arthroplasty years after the index procedure need to be concerned about the persistence of Propionibacterium?

The authors reviewed the medical records of 148 revision arthroplasties performed between July 2008 and June 2013 to find those revisions performed at least 3 years after the index procedure and at which intraoperative cultures were strongly positive for Propionibacterium.

They identified 14 cases of revision surgery performed 8 ± 4 years after the original arthroplasty for which deep cultures were strongly positive for Propionibacterium. A total of 109 specimens were obtained, 84 of which were positive. All 14 patients were male.

They concluded 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.

Comment: One of the features of a Propionibacterium infection in a shoulder arthroplasty is the delayed onset of stiffness and pain after a 'honeymoon' of excellent comfort and function.