The aim of this study was to assess the role
of synovial C-reactive protein (CRP) in the diagnosis of chronic periprosthetic
hip infection. We prospectively collected synovial fluid from 89
patients undergoing revision hip arthroplasty and measured synovial
CRP, serum CRP, erythrocyte sedimentation rate (ESR), synovial white
blood cell (WBC) count and synovial percentages of polymorphonuclear
neutrophils (PMN). Patients were classified as septic or aseptic
by means of clinical, microbiological, serum and synovial fluid
findings. The high viscosity of the synovial fluid precluded the
analyses in nine patients permitting the results in 80 patients
to be studied. There was a significant difference in synovial CRP
levels between the septic (n = 21) and the aseptic (n = 59) cohort.
According to the receiver operating characteristic curve, a synovial
CRP threshold of 2.5 mg/l had a sensitivity of 95.5% and specificity
of 93.3%. The area under the curve was 0.96. Compared with serum
CRP and ESR, synovial CRP showed a high diagnostic value. According
to these preliminary results, synovial CRP may be a useful parameter
in diagnosing
When using a staged approach to eradicate chronic infection after total hip replacement, systemic delivery of antibiotics after the first stage is often employed for an extended period of typically six weeks together with the use of an in situ antibiotic-eluting polymethylmethacrylate interval spacer. We report our multi-surgeon experience of 43 consecutive patients (44 hips) who received systemic vancomycin for two weeks in combination with a vancomycin- and gentamicin-eluting spacer system in the course of a two-stage revision procedure for deep infection with a median follow-up of 49 months (25 to 83). The antibiotic-eluting articulating spacers fractured in six hips (13.9%) and dislocated in five patients (11.6%). Successful elimination of the infecting organisms occurred in 38 (92.7%) of 41 hips with three patients developing superinfection with a new organism. We conclude that prolonged systemic antibiotic therapy may not be essential in the two-stage treatment of a total hip replacement for Gram-positive infection, provided that a high concentration of antibiotics is delivered locally using an antibiotic-eluting system.
