Poor predictive value of broad-range PCR for the detection of arthroplasty infection in 92 cases

Figures & data

Table 1.  Pathogens isolated from preoperative aspiration

	Hips	Knees	Total
Coagulase-negative Staphylococcus	3	1	4
Staphylococcus aureus	3	0	3
Enterococcus	1	0	1
Streptococcus sanguis	1	0	1
Group A Streptococcus	1	0	1

Table 2.  Bacteria isolated from intraoperative cultures from infected joints. Specimens from 2 hips grew more than 1 type of organism

	Hips	Knees	Total
Coagulase-negative Staphylococcus	5	1	6
Staphylococcus aureus	1	1	2
Streptococcus viridans	2	0	2
Enterococcus	2	0	2
Diphtheroids	2	0	2

Table 3.  Contaminants isolated from intraoperative cultures. Specimens from 2 hips grew more than 1 type of organism

	Hips	Knees	Total
Coagulase-negative Staphylococcus	4	1	5
Streptococcus viridans	1	0	1
Streptococcus mitis (viridans group)	0	1	1
Group D Streptococcus	2	0	2
Streptococcus	1	0	1
Candida	1	0	1

Table 4.  Results of tests used for the detection of prosthetic infection

	Sensitivity	specificity	Accuracy	Positive predictive value	Negative predictive value
ESR	0.75	0.68	0.68	0.26	0.95
CRP	0.67	0.64	0.64	0.22	0.93
Aspiration	0.7	0.95	0.9	0.78	0.92
Tissue culture	0.75	0.96	0.93	0.75	0.96
Histology	0.92	1	0.99	1	0.99
PCR	0.92	0.74	0.76	0.34	0.98