Retrospective Analysis of Failure Causes and Microbiologic Features of Periprosthetic Joint Infection in Hip and Knee Arthroplasty Cases

Background: Failures of bipolarhip hemiarthroplasty (BHA) and total knee arthroplasty (TKA) lead to time- or energy-consuming revision arthroplasty, which is considered as a big challenge to arthroplasty surgeons and patients. Periprosthetic joint infection (PJI) has been identified as one of the most difficult causes to treat. This study aims to examine the potential causes of failure following BHA/TKA and microbiological testing results with antibiotic susceptibility in PJI cases. Materials and Method: We retrospectively reviewed the causes of failures after BHA in 92 patients and after TKA in 48 patients admitted to Pyongyang University of Medical Sciences Hospital. Then we investigated the microbiological etiology of 53 hip and 26 knee periprosthetic joint infections that were treated with the two- staged revision and analyzed the antibiotic susceptibility of causative bacteria. Results: The main reasons for failures of primary BHA were aseptic loosening (43/92) and periprosthetic joint infection (34/92), whereas in revision BHA they were infection (8/14) and dislocation of the inner head (3/14). The main reasons for failures of primary TKA were infection (25/48) and aseptic loosening (8/48), whereas in revision TKA they were infection (9/13)and flexion contracture (2/13). Staphylococcus aureus and E. coli were themost common causativemicroorganisms in hip and knee PJI cases. Gram-positive bacteriawere sensitive to ceftriaxone + gentamicin +rifampicin and levofloxacin/cefotaxime was susceptible to gram-negative bacteria. Conclusion: The present study might be helpful to expand our knowledge about the failure modes of BHA and TKA and to establish the antibiogram for empiric regimens based on the antibiotic susceptibility results.