Risk factors for failure of two-stage revision arthroplasty for infected hip prosthesis: review of the literature and single centre cohort analysis

Periprosthetic joint infections (PJI) are one of the most dangerous complications in hip surgery. "Two-stage" revision surgery is the treatment of choice. Nevertheless, 5-10% of failures are reported. The aim of this study is to evaluate which factors determine the failure of the two-stage revision in patients affected by hip PJI. PATIENTS AND METHODS: We retrospectively enrolled 21 patients treated for hip PJI who had undergone two-stage revision surgery. The diagnosis had been made using criteria established by the Musculoskeletal Infection Society (MSIS) and readapted by the Philadelphia Consensus Conference group. The patients underwent periodic clinical and laboratory controls after the surgical procedure. The two-stage revision treatment was considered unsuccessful in the event of re-infection or in case of severe complications occurring within one year from the treatment. RESULTS: At a mean follow-up of 23.8 months 57% healed with no complications. The reinfection rate was 19% and, after the 3rd stage, the final failure rate was 9.5%. The study has shown, with statistical significance, that a greater number of previous surgical procedures (p<0.05, OR=22) and BMI>25 (p<0.05, OR=4) represent increased risk factors in predicting the failure of two-stage revision surgery. Age, CRP, ESR and a shorter lapse (<60 days) between 1st and 2nd stage were recorded in the failure cases, and have to be considered, even if not statistically significant. CONCLUSIONS: Knowing the factors responsible for the increased failure of two-stage revision could lead to closer monitoring and more aggressive management in those patients expected to be at greater risk of reinfection. Obesity and multiple surgeries are risk factors for failure.