Saturday, January 9, 2016

Shoulder arthroscopy after shoulder arthroplasty - considering infection with Propionibacterium

Indications and outcomes of shoulder arthroscopy after shoulder arthroplasty.

These authors reviewed 11 Level IV publications containing 84 patients on shoulder arthroscopy in patients after shoulder arthroplasty.

The most common indications for shoulder arthroscopy in the setting of shoulder arthroplasty were pain or loss of range of motion without a clear diagnosis, suspected periprosthetic infection, and rotator cuff assessment.
Of the 84 patients, 37 (44%) required further surgery after arthroscopy. Twenty-one patients (25%) underwent an open revision arthroplasty for a periprosthetic infection,. Four patients (6%) underwent a resultant revision shoulder arthroplasty for aseptic component loosening (4%), component wear (1%), or malposition (1%).

Comment:  While an arthroscopic 'tune up' of a prior arthroplasty that is painful or stiff sounds attractive, evidence in support of this approach is lacking. The principal value of post arthroplasty arthroscopy appears to be obtaining specimens for tissue culture to evaluate the possibility of periprosthetic shoulder infection. This has been discussed in a prior post that pointed out while  fluoroscopically guided glenohumeral aspiration is specific it is relatively insensitive to the presence of Propionibacterium.

Recognizing the prevalence of Propionibacterium in failed shoulder joint replacement, a reasonable approach to the painful arthroplasty without apparent cause may be:
(1) fluoroscopically guided glenohumeral aspiration with careful fluid culturing directed at identifying Propionibacterium
(2) if the aspirate is negative, proceed to arthroscopy with multiple tissue biopsies submitted for culture directed at identifying Propionibacterium
(3) if the arthroscopic cultures are negative, consider open revision with multiple tissue biopsies submitted for culture directed at identifying Propionibacterium and treating the patient with antibiotics until the results of the cultures are finalized.