**4.1.2 Hip infections**

448 Recent Advances in Arthroplasty

an individual regimen of systemic and localized antibiotic treatment for two-stage approaches using cement spacers supplemented with antibiotics (Fink et al., 2011). However, the utility of pre-operative biopsies is controversial between studies, mainly due to differences regarding the number of biopsies obtained and the definitions of infection

We are convinced that pre-operative identification of the causative agent is a key factor for successful eradication of arthroplasty infections. It enables the design of individualized systemic and localized antibiotic therapy, while intra-operative tissue samples confirm the diagnosis and allow modification of the systemic antibiotic regimen if necessary. The diagnostic workflows we have established to identify hip and knee infections are outlined

To minimize the effect of false-negative results, we call for an antibiotic-free interval of 4 weeks before sampling for microbiological diagnosis. At our clinic we withhold perioperative antibiotic prophylaxis until samples have been drawn, and we have not

**method** 

pediatric blood culture vial

frozen sections

**no. of samples**

native 5 identical

**definition of infection** 

organisms in ≥ 2

samples

5 ≥ 5 neutrophils per 400 x field in 10 fields

**storage detection method processing** 

14-day automated culture

anaerobic culture

sheep blood agar chocolate agar Schaedler agar

infusion broth

Schaedler broth

staining

Table 2. Overview over the laboratory methods used to detect arthroplasty infection.

The definitive diagnosis of arthroplasty infection is established with multiple tissue biopsies taken from the periprosthetic membrane and other macroscopically conspicuous sites

4°C 14-day aerobic and

brain-heart


(Fink et al., 2008, 2009; Meermans & Haddad, 2010).

**4. Our own approach and future prospects** 

below.

**sample material** 

**synovial aspiration fluid** 

**tissue biopsies** 

experienced adverse outcomes.

**4.1.1 Samples and diagnosis** 

room temp.

**4.1 The value of both pre-operative and intra-operative sampling** 

An overview of the laboratory procedures is given in Table 2.

By default, we carry out two-stage revisions of infected hips in our clinic (Fink et al., 2009). Localized antibiotics applied via cement spacer and systemic antibiotics are customized for administration at the time of revision surgery (Fink et al., 2011).

The general sampling algorithm is depicted schematically in Fig. 3. In addition, we obtain pre-operative tissue biopsies for culture and histology if the joint aspiration culture is negative but the risk assessment suggests indicates septic implant failure.
