Table 1.

Summary findings on differential leukocyte count in identifying persistent infection in patients with spacers

Publication	Population	Proposed cutoff	Sensitivity	Specificity	Positive predictive value	Negative predictive value	Accuracy
Shukla et al. 2010 [9]	87 hip spacers	3,528 cells/μL	78%	96%	-	-	94%
Shukla et al. 2010 [9]	87 hip spacers	79% PMN	78%	82%	-	-	82%
Kusuma et al. 2011 [10]	76 knee spacers	1,102 cells/μL	75%	61%	-	-	62%
Kusuma et al. 2011 [10]	76 knee spacers	71% PMN	75%	66%	-	-	66%
Hoell et al. 2016 [33]	115 spacers (56 hips and 59 knees)	970 cells/μL	31%	39%	11%	71%	-
Hoell et al. 2016 [33]	115 spacers (56 hips and 59 knees)	-	-	-	-	-	-
Newman et al. 2017 [38]	77 hip spacers	3,000 cells/μL	47%	87%	50%	85%	78%
Newman et al. 2017 [38]	77 hip spacers	80% PMN	76%	80%	52%	92%	79%
Zmistowski et al. 2017 [39]	128 spacers (40 hips and 88 knees)	1,234 cells/μL	44%	77%	26%	88%	70%
Zmistowski et al. 2017 [39]	128 spacers (40 hips and 88 knees)	57% PMN	67%	59%	24%	90%	60%
Muhlhofer et al. 2018 [12]	141 spacers (45 hips and 68 knees)	Not specified	10%	81%	10%	81%	-
Muhlhofer et al. 2018 [12]	141 spacers (45 hips and 68 knees)	Not specified	10%	79%	9%	81%	-
Boelch et al. 2018 [31]	94 knee spacers	4,450 cells/μL	50%	76%	17%	97%	-
Boelch et al. 2018 [31]	94 knee spacers	-	-	-	-	-	-
Boelch et al. 2018 [32]	92 hip spacers	2,000 cells/μL	25%	97%	67%	82%	-
Boelch et al. 2018 [32]	92 hip spacers	-	-	-	-	-	-
Ascione et al. 2021 [37]	82 knee spacers	934 cells/μL	82%	82%	41%	98%	-
Ascione et al. 2021 [37]	82 knee spacers	52% PMN	82%	78%	36%	97%	-