Two-Year Outcomes of Infected Total Hip Arthroplasty Treated With Debridement and Implant Retention

Abstract

Background. Prosthetic joint infection (PJI) is a grave complication of total hip arthroplasty (THA). Two-stage exchange can be curative but is morbid and costly. De- bridement, antibiotics, and implant retention (DAIR) is appropriate in some patients, but factors effecting success remain unclear. We studied a large cohort with infected THA treated with DAIR at our specialized orthopedic hospital, examining potential factors associated with 2-year implant retention. Methods. A retrospective cohort ofTHA PJI treated with DAIR was identified by query of hospital coding records. Primary endpoint was defined as 2-year implant re- tention. Data from multiple sources included comorbidities, Musculoskeletal Infection Society (MSIS) criteria for PJI, duration ofsymptoms prior to surgery, time from index surgery, pathogen and sensitivities, surgical details, and treatment outcomes. Results. Sixty-nine patients meeting MSIS criteria for THA PJI were identified. Sixty-two percent of THA were retained at 2 years. Pathogens included methicillin- sensitive (22%) and methicillin-resistant Staphylococcus aureus (17%), coagulase-neg- ative staphylococci (15%), and streptococci (22%); 6% of cases were culture-negative. Comorbidities included obesity (mean BMI 29.8), diabetes (15%), history of tobacco (39%), and rheumatologic disease (13%). No significant associations were noted be- tween primary outcome and patient or implant age, BMI, comorbidities, or symptom duration at diagnosis. The 57% ofpatients who underwent polyethylene liner exchange (PLE) during debridement fared better than those who did not (77% versus 43% suc- cess, p = 0.004). Staphylococcal infections fared poorly, compared to non-Staphylococ- cus (43% versus 84% success, p < 0.001); among staphylococcal PJI, rifampin use was not associated with success (28% versus 58% success, p = 0.065). In multivariable mod- eling, absence of staphylococcal infection (OR = 0.14; 95% CI, 0.04–0.47; p =0.002) and PLE (OR = 4.7; 95% CI, 1.5–15; p = 0.01) were associated with success. Conclusion. We present 2-year outcomes on THA PJI treated with DAIR. The likelihood of implant retention is increased in non-staphylococcal infection and with polyethylene liner exchange. Our data may help guide evidence-based decision- making in THA PJI.