The aim of this meta-analysis was to determine based on evidence from all randomised controlled trials whether closed suction drainage is preferable to no drainage for all types of Orthopaedic surgery. Trials were identified by a search strategy developed by the Cochrane Collaborative involving hand searching of major journals and computer aided searching of other databases.

Twenty-nine studies were identified but nine were excluded owing to problems with study design or under-reporting of outcomes. Twenty studies involving 2749 patients with 2946 wounds were included in our analysis. These studies included 566 THRs, 860 TKRs, 333 proximal femoral fractures, 287 non-emergency fractures and 900 other procedures.

Two reviewers independently extracted data from the papers. Methodology of the studies was assessed using a nine point scoring system. Generally the studies scored poorly, possibly owing to under-reporting of outcomes.

No study clearly differentiated against deep and superficial wound infections therefore all wound infections were considered together. No differences between the drained and the undrained groups was noted for wound infection overall or in any of the operative sub-groups. Similarly no difference was found for the outcomes of wound haematomas, infection, wound dehiscence, transfusion requirements, limb swelling, venous thrombosis, mortality or hospital stay.

There was a tendency to a higher re-operation rate for wound healing complications and significantly more patients required transfusion in the drained group. The only benefit that was shown in favour of the use of drains was that significantly more patients in the undrained group required dressing reinforcement.

Based on the randomised, controlled trials to date, the routine use of closed suction drainage in Orthopaedic surgery is questionable.

Differentiating cases of aseptic loosening of total hip arthroplasty (THA) from loosening due to low-grade infection can often be difficult. It is possible that some cases of ‘aseptic’ loosening may be related to unidentified bacterial infection.

Using Polymerase Chain Reaction (PCR), this study attempted to identify the frequency with which bacterial DNA could be observed at revision arthroplasty for what was considered ‘aseptic’ loosening.

All revision cases had to fulfil strict criteria to be considered aseptically loose In all cases operative specimens from the synovial fluid, synovium, femoral and acetabular membranes where possible were sent for analysis by histology, bacteriology and by PCR to identify the presence of the 16S bacterial ribosomal fraction, an indicator of bacterial DNA. Ten bacteria per millilitre of tissue/fluid were the threshold for detection. As a control for environmental contamination, specimens from primary THA were also sent for analysis in the same manner as revisions.

The identification of bacterial DNA in at least one sample from a patient was considered a positive case result.

45 revision THA were identified over a 3-year period (1998–2001). From those 45 revision cases, 163 specimens were sent for analysis by PCR. These specimens were compared to the control group of 34 primary THA from which 91 specimens were sent for analysis by PCR. When analysed by specimens positive by PCR, bacterial DNA was identified in 55 of 163 specimens sent from the 45 revision THA. This compared with 21 of 91 specimens positive by PCR sent from the 34 primary THA (p=0. 07).

When analysed by cases positive by PCR, bacterial DNA was identified in 29 of 45 revision THA and in 8 of 34 primary THA (p< 0. 001).

PCR is a sensitive test for detecting infection in revision THA. Results from the primary THA cases would suggest there is at least a 23% false positive rate even with negative bacterial culture. The increased frequency with which bacterial DNA has been identified in ‘aseptically’ loose revision THAs, however, is unlikely to be due solely to environmental contamination. These results may have relevance for our interpretation and understanding of aseptic loosening as well for the diagnosis of prosthetic infection.