159 Current Practice of Intra-Operative Sampling During Revision Surgery of the Knee for Prosthetic Joint Infection at a High-Volume District General Hospital

Abstract

Abstract Aim Successful treatment of prosthetic joint infection (PJI) involves surgical interventions and identification of infecting organisms to enable targeted antimicrobial therapy. Current PHE guidelines recommend 3–5 intra-operative samples to be taken using separate instruments for each, swabs are discouraged. We audited the revision arthroplasty practice at Barking, Havering, Redbridge University Trust (BHRUT), specifically comparing intra-operative sampling for infected revision knee procedures with these guidelines. Method Retrospective cohort study of all prosthetic knee infection cases, as defined by the Musculoskeletal Infection Society criteria, at BHRUT between December 2011 to May 2020. A review of case notes collected various key data points, focusing on intraoperative sample, type, number, and technique. Point biserial correlation analysis was performed to determine statistical significance. Results 119 revision knee arthroplasty procedures were performed in the 8.5-year study period. 31 (26%) were for prosthetic joint infection (n=29 patients), n=2 patients had re-revision procedures for second PJI. Number of samples taken ranged from 1–12 with a mode of 6. N=27 (87%) cases had the recommended number of total samples taken, of these n= 20 (65%) had five or more samples taken, N=24 (77%) cases had three or more samples taken and n=18 (58%) had five or more samples. Conclusions Current management of infected knee arthroplasty presents great variability in intra-operative sampling technique. Sample collection adheres to national guidelines in 77% of cases. We recommend implementation of a standardised approach to sampling through inclusion of a five scalpel and five forceps pack specifically for sampling in theatre for all suspected PJI's.