Total Hip Arthroplasty (THA) remains a gold standard intervention for symptomatic hip arthritis. Associated surgical site infections (SSI) can have serious consequences including superficial and deep joint infections or requiring revision surgeries. Prophylactic antibiotics remain a mainstay in reducing SSI and revision rates, however duration remains controversial. Given the rise in use of single dose prophylactic antibiotics, our aim was to ascertain the rate of deep infections in patients undergoing primary THAs and associated revision rates.

This retrospective study was carried out at The Princess Alexandra Hospital, a District General Hospital based in the United Kingdom. All THAs were identified between January 2013 and December 2016 using the hospital’s electronic records system. Trust Arthroplasty Records, discharge summaries and clinic letters were used for data collection. Inclusion criteria included primary THA, age >50y, and single dose antibiotic only. Complex and revision THAs were excluded. Patients were followed up for 4 years. Patient demographics, comorbidities including 'at risk' (immunocompromised or with ASA>3) were identified. Deep infection was defined as cases requiring joint aspiration, debridement and washout or revision.

1001 patients met the inclusion criteria. All patients received a single dose of intravenous cefuroxime 1.5g pre-operatively as per the Trust microbiology guidelines unless there was a recorded contraindication. There were 26 (2.59%) deep infections of which 13 cases (1.29%) subsequently had a revision. Average time from primary surgery to washout was 2.38 months and revision was 15.67 months. Of interest, 15 of the 26 (57.7%) patients with deep infections were identified as ‘at risk’. Increasing age and length of stay were both associated with higher rate of SSIs (p=0.044 and p=0.047 respectively).

This study demonstrates that single dose antibiotics in primary THA patients is a cost-effective approach for preventing SSIs. The deep infection and revision rates were comparable with previously reported SSI rates for primary THAs. Those ‘at risk’ may benefit from further doses of antibiotics post-operatively – this requires further investigation.