To investigate surgical interventions for periprosthetic joint infection (PJI) after total knee arthroplasty and characteristics of prognosis.

Sixty-two patients with PJI after total knee arthroplasty from January 2000 to November 2016 were reviewed retrospectively, included with 17 males and 45 females. The mean age was 66.0±10.2 years old (37-85). Fourty-nine patients were diagnosed with osteoarthritis, 9 with rheumatoid arthritis, 2 with secondary ankyloses after suppurative arthritis and 2 with hemophilia arthritis. Forty-one patients underwent unilateral total knee arthroplasties, and 21 bilateral total knee arthroplasties. Characteristics of PJI, including infection types, existence of sinus tract, infectious pathogen, surgical intervention and patients' prognosis, were collected.

Twenty-four patients underwent open debridement with prothesis retention. In the 14 successful cases, medial time interval between primary total knee arthroplasty and debridement was 33 days. One case of positive Methicillin resistant Staphylococcus aureus culture of joint aspiration, and 1 case formed sinus tract. In 10 cases of failed debridement, the medial time interval was 270 d. Intra-articular culture presented 4 cases of antibiotic resistant bacteria, and 6 cases formed sinus tract. Except for one patient gave up treatment and another received arthrodesis, the other 8 failed cases were all treated with revisions. In 46 revisions, nine patients underwent one-stage revisions. The mean time interval between primary total knee arthroplasty and revision was 15.9±14.5 d. Intra-articular culture presented 3 cases of antibiotic resistant bacteria, and 1 case formed sinus tract. In the other 37 two-stage revisions, the mean time interval was 1 045.7±1 044.1 d. Intra-articular culture showed 15 cases of antibiotic resistant bacteria, and 12 cases formed sinus tract. The mean follow-up duration was 73.9±48.2 months. At the last follow-up, all patients were free of antibiotics treatment. The mean Knee Society Score (KSS) was 85.9±4.3 after successful open debridement with prothesis retention. The KSS of one-stage revision patients was 78.5±3.3, while that of two stage revision patients was 65.7±7.4. Statistical difference was found among groups (P<0.05).

For PJI within 3 weeks after total knee arthroplasty without sinus tract or intra-articular culture of antibiotic resistant bacteria, open debridement with prosthesis retention could be recommended. One stage revision could be applied in infectious cases which appeared between 3 weeks to 1 month after primary surgery or in cases with unstable prostheses found in open debridement. For infectious cases longer than 1 month after primary procedure or those with sinus tract, severe soft tissue deficiency, intra-articular culture of antibiotic resistant bacteria, two-stage revision could be recommended.

Arthroplasty, replacement, knee; Prosthesis-related infections; Reoperation; Debridement