Abstract
Aim: To assess the infection rate following Primary Lower Limb Arthroplasty using single dose gentamicin antibiotic prophylaxis compared to a traditional three doses of cephalosporin.
Material And Methods: All patients undergoing primary Total Hip and Knee joint replacements over 6 months (October 2007 to March 2008) at 3 participating hospitals were prospectively followed up to assess perioperative infection rates. Joint replacements were defined as having infection by the UK Health Protection Agency Surgical Site Surveillance (SSI) criteria. All patients received single dose antibiotic prophylaxis using intravenous Gentamicin 4.5mg/kg body weight adjusted for body mass index.
This group of patients were compared with previous data collected over a 6 month period (Jan to Mar 2007 and Oct to Dec 2005) from the same hospitals for infection rates in Lower Limb Arthroplasty using 3 doses of Cefuroxime 750mg as antibiotic prophylaxis.
Return to theatre data was collected independently after introduction of gentamicin to compare with previous data.
Results: 408 patients underwent Total Hip Replacements (THR) and 458 patients underwent Total Knee Replacements (TKR) during the study period. This was compared with 414 patients who underwent THR and 421 patients who underwent TKR during a 6 month period over 2 years.
Surgical site infection was detected in 9 THRs (2.2%) and 2 TKRs (0.44%) in the study group as compared to infection in 13 THRs (3.1%) and 12 TKRs (2.9%) in the control group.
Using the Fisher Exact test the infection rates in THRs were not significantly different between the 2 groups (p value – 0.52) but the infection rates were significantly reduced in the study group for TKRs (p value – 0.005).
There were no complications with the use of Gentamicin as antibiotic prophylaxis.
The return to theatre was 2.42% (28/1157) after introduction of Gentamicin as compared with 1.85% (37/2005) [p value – 0.172] before this. This was a cause for concern, although not a significant difference.
Cefuroxime is known to promote Clostridium difficile infection and was removed from the hospital pharmacy to help meet a UK government targets to reduce the incidence. The rate of Clostridium difficile infection was reduced within the hospital with the use of single dose antibiotic prophylaxis although other measures to reduce its incidence were also introduced.
Conclusions: This study shows that the use of single dose antibiotic prophylaxis using Gentamicin is effective in preventing SSI as defined in the HPA definition. It is safe to use and reduces rate of Clostridium difficile associated diarrhoea.
However, be wary of increased rate of return to theatre following use of gentamicin.
Further period of evaluation and study is needed before it is recommended for routine use in present or modified form.
Correspondence should be addressed to BHS c/o BOA, at the Royal College of Surgeons, 35–43 Lincoln’s Inn Fields, London, WC2A 3PE, England.
