Two-year Outcomes of Infected Total Hip Arthroplasty (THA) Treated With Debridement and Implant Retention

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. Debridement, 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 of THA PJI treated with DAIR was identified by query of hospital coding records. Primary endpoint was defined as 2-year implant retention. Data from multiple sources included comorbidities, Musculoskeletal Infection Society (MSIS) criteria for PJI, duration of symptoms prior to surgery, time from index surgery, pathogen and sensitivities, surgical details, and treatment outcomes.

Results: 69 patients meeting MSIS criteria for THA PJI were identified. 62% of THA were retained at 2 years. Pathogens included methicillin-sensitive (22%) and methicillin-resistant Staphylococcus aureus (17%), coagulase-negative 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 between primary outcome and patient or implant age, BMI, comorbidities, or symptom duration at diagnosis. The 57% of patients who underwent polyethylene liner exchange (PLE) during debridement fared better than those who did not (77% vs. 43% success, p=0.004). Staphylococcal infections fared poorly, compared to non-staphylococcus (43% vs. 84% success, p<0.001); among staphylococcal PJI, rifampin use was not associated with success (28% vs. 58% success, p=0.065). In multivariable modeling, absence of staphylococcal infection (OR = 0.14, [95% CI 0.04-0.47], p=0.002) and PLE (OR = 4.7 [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.