High diagnostic value of synovial biopsy in periprosthetic joint infection of the hip.
BACKGROUND
The role of the synovial biopsy in the preoperative diagnosis of a periprosthetic joint infection (PJI) of the hip has not been clearly defined.


OBJECTIVE
We asked whether the value of a biopsy for a PJI is greater than that of aspiration and C-reactive protein (CRP).


METHODS
Before revision in 100 hip endoprostheses, we obtained CRP values, aspirated the joint, and obtained five synovial biopsy samples for bacteriologic analysis and five for histologic analysis. Microbiologic and histologic analyses of the periprosthetic tissue during revision surgery were used to verify the results of the preoperative diagnostic methods. The minimum followup was 24 months (median 32; range, 24-47 months).


RESULTS
Forty-five of the 100 prostheses were identified as infected. The biopsy, with a combination of the bacteriologic and histologic examinations, showed the greatest diagnostic value of all the diagnostic procedures and led to a sensitivity of 82% (95% CI, ± 11%), specificity of 98% (95% CI, ± 4%), positive predictive value of 97% (95% CI, ± 5%), negative predictive value of 87% (95% CI, ± 8.3%), and accuracy of 91%.


CONCLUSIONS
The biopsy technique has a greater value than aspiration and CRP in the diagnosis of PJI of the hip (Masri et al. J Arthroplasty 22:72-78, 2007). In patients with a negative aspirate, but increased CRP or clinical signs of infection, we regard biopsy to be preferable to just repeating the aspiration.


METHODS
Level II prognostic study. See Guidelines for Authors for a complete description of levels of evidence.
Department of Joint Replacement, General and Rheumatic Orthopaedics, Orthopaedic Clinic Markgröningen, Kurt-Lindemann-Weg 10, Markgröningen 71706, Germany. b.fink@okm.de
Bernd
B
Fink
Alexander
A
Gebhard
Martin
M
Fuerst
Irina
I
Berger
Peter
P
Schäfer
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000295:instrumentation; D001431:Bacteriological Techniques; D015415:Biomarkers / Q000097:blood; D001706:Biopsy / Q000379:methods; D001707:Biopsy, Needle; D002097:C-Reactive Protein / Q000032:analysis; D005260:Female; D006621:Hip Joint / Q000382:microbiology / Q000473:pathology / Q000601:surgery*; D006622:Hip Prosthesis / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016459:Prosthesis-Related Infections / Q000175:diagnosis* / Q000382:microbiology / Q000473:pathology / Q000601:surgery; D012086:Reoperation; D012680:Sensitivity and Specificity; D000074402:Synovectomy; D013583:Synovial Membrane / Q000382:microbiology / Q000473:pathology
D015415:Biomarkers; D002097:C-Reactive Protein