Abstract:[Objective] To explore the clinical outcomes of debridement, antibiotics and implant retention (DAIR) combined with irriga- tion drainage for periprosthetic joint infection (PJI) . [Methods] A retrospective study was done on 21 patients (21 knees) who were admit- ted into our hospital for acute PJI from January 2012 to June 2020. All patients were treated with DAIR combined with irrigation and drain- age. The VAS and HSS scores, as well as knee extensor-flexion range of motion (ROM) and laboratory test results were compared among dif- ferent time points, additionally the successful rate of infection control was evaluated. [Results] All patients were successfully operated on without serious complications such as vascular and nerve injury. The 21 patients were followed up for (3.62±2.50) years. Among them, 15 cases got successful infection control, accounted for 71.43% , whereas the remaining 6 patients had infection recurred, accounted for 28.57%, which controlled well after the two-stage revision. The HSS score and ROM increased significantly (P<0.05) , whereas the VAS score decreased significantly over time postoperatively (P<0.05) . In terms of bacteriology, 14 patients got positive results, while 7 were of negative among the 21 patients. The positive results involved 8 cases of staphylococcus aureus, including 5 cases of MRSA; 3 cases of Staphylococcus epidermidis; 1 case of pseudomonas aeruginosa and 2 cases of gram-negative bacilli. In terms of blood test, ESR, CRP and IL-6 were significantly decreased after operation compared with those preoperatively (P<0.05) . The regular radiographic checks revealed that the prosthetic components remained in proper positions without fracture, loosening, and no obvious lightening shadow was seen. [Conclusion] The DAIR combined with irrigation drainage do effectively control infection and preserve good joint function for acute PJI.