Table II.

Periprosthetic infections in patients after TSA and shoulder hemiarthroplasty from registry databases confirmed by use of patients’ medical records with gold-standard definitions

	TSA (N = 2,588)
Potential periprosthetic infections identified   from registry databases	46
No records	2
Superficial infection or hematoma	7
No documentation of infection	5
Confirmed total deep periprosthetic infections	32
Staphylococcus coagulase negative	5
S aureus *	10
Methicillin-resistant S aureus	0
P acnes	6
Streptococcus (Streptococcus pneumoniae or   β-hemolytic Streptococcus)	2
Serratia	1
Clostridium species	0
Pseudomonas	0
Bacillus species	0
Enterococcus species	0
Clinical septic arthritis (with or without   pus or serosanguineous fluid or necrotic   joint tissue or positive blood culture but   no organism on joint fluid/tissue culture   or culture not done)†	8

Superficial infection was defined as infection in skin and subcutaneous tissue without any extension beyond the fascial planes and without any extension into joint or pericapsular tissue. In all cases, these were treated with oral antibiotics, mostly without any incision and drainage.

^*One patient had Staphylococcus reported without specification of whether it was S aureus or Staphylococcus coagulase negative; one patient had 2 species of Staphylococcus and Propionibacterium.

^†The distributions of the 8 patients were as follows: clinically suspected septic arthritis plus pus or purulent material with culture not done or negative (n = 2); clinically suspected septic arthritis plus serosanguineous fluid with positive blood culture or bacteria in broth but not in culture (n = 4); clinically suspected septic arthritis plus serosanguineous fluid with culture negative (n = 1); and clinically suspected septic arthritis plus necrotic tissue (n = 1). In 5 cases prostheses were removed, debridement was performed in 1 patient without removal of components, and 2 patients were treated conservatively.