Table 2 Findings in 72 revisions of hip and knee arthroplasties on indication of aseptic failure. The groups are defined by results obtained with the reference method, i.e. culture of five periprosthetic synovial tissue biopsies from each procedure. Gr. 1: 0 positive, Gr. 2–3 positive. Gr. 3: 3–5 positive

No. of revisions (and patients)

62 (61)

6

4

Arthroplasties (no.)

THA 29; TKA 33

THA 3; TKA 3

THA 3; TKA1

Prosthesis age, years (median, interquartile range (0.25–0.75))

9.2 (2.7–15.8)

11.8 (3.1–19.9)

7.6 (5.5–9.2)

Prior antibiotic treatment (no.)

3

0

0

CRP (μg/mL, (median, interquartile range (0.25–0.75))

7.4 (1.5–8.5)^c

6.5 (1–2.5)^c

28.2 (20.3–39.5)^c

WBC (range 10⁹/L, (median, interquartile range (0.25–0.75))

7.2 (6.1–8.4)

5.9 (3.9–6.8)

7.5 (6.4–9.1)

Number of positive periprosthetic synovial tissue biopsies (a set comprises 5 biopsies)

0

1–2

3–5

Aseptic failure

61

4

0

Prosthetic joint infection

0

1^a

4^a

Indeterminable

1^a

1^a

0

Joint fluid

Cul 2

Mol 1

Cul 2

Mol 0

Cul 3

Mol 1

Sonication fluid

Cul 2

Mol 0

Cul 1

Mol 1

Cul 3

Mol 3

Bone biopsy

Cul 0

Mol 2

─

Cul 1

Mol 0

Swab from prosthetic element

Cul 1

Mol 3

─

Cul 2

Mol 1

Follow-up period, days (median & range)

396 (3^b-1097)

367 (47–1131)

363 (96–1051)

Aseptic failure

4

0

0

Prosthetic joint infection

1

0

0