CYCLICAL LOCAL EXCHANGE WITH ANTIBIOTIC REVISION (CLEAR) PROTOCOL HAS DECREASED ONE-YEAR FAILURE VERSUS REPEAT TWO-STAGE EXCHANGE ARTHROPLASTY FOR RECALCITRANT PJI

Aim Recurrent periprosthetic joint infection (PJI) is the leading cause of failure following an initial two-stage exchange of total knee arthroplasty (TKA). Repeat two-stage exchange arthroplasty is considered the standard-of-care treatment. However, repeating two-stage exchange arthroplasty for recalcitrant PJI carries high morbidity and failure rates at approximately 60% at 1-year follow up. An accelerated protocol with abbreviated seven-day interstage period, the Cyclical Local Exchange with Antibiotic Revision (CLEAR) Protocol, was developed to reduce these complications. This study compared the CLEAR protocol for two-stage exchange arthroplasty to conventional two-stage exchange arthroplasty in a high-risk population of patients who previously failed PJI treatment with two-stage exchange arthroplasty. Methods This IRB-approved multi-center cohort study evaluated patients who failed ≥ 1 previous two-stage exchange arthroplasty for chronic PJI of TKA. All patients underwent explantation and antibiotic spacer placement. Comparisons were made between an experimental cohort of patients prospectively undergoing two-stage exchange with cyclical intra-articular vancomycin and tobramycin irrigation during a seven-day interstage period (CLEAR protocol) and a control cohort who underwent repeated standard two-stage exchange. Exclusion criteria were follow-up <6 months, PJI treatment other than two-stage exchange, knee trauma, and aseptic loosening. Primary outcome was treatment results at 1 year, assessed using tiered 2019 MSIS criteria for success (Tiers 1+2) and failure within 1 year (Tiers 3C-3F). Secondary outcomes included length of interstage duration. Results Overall, 64 patients were included (36 in the control group, 28 in the CLEAR group). Baseline characteristics were similar between groups. At 1 year, the CLEAR group demonstrated higher success rates as defined by the primary outcome of avoiding revision surgery (MSIS Tiers 1+2: 89% vs 36%, P<0.001). The rate of MSIS Tier 2 success was significantly higher in the clear group (39% vs 5.6%, P<0.001). Multivariable logistic regression demonstrated significantly higher odds of Tiers 1+2 success for the CLEAR group (adjusted OR: 23.9; 95% CI: [5.56, 154]; P<0.001). The interstage period was markedly shorter in the CLEAR group. Conclusions At 1 year, the CLEAR protocol for two stage exchange demonstrated lower failure rates than traditional two stage exchange arthroplasty as defined by revision surgery (11% vs 64%) as well as shorter interstage duration. Extended postoperative antibiotics (Tier 2 success) was not unexpected given the historical high baseline failure risk. Further prospective studies and increased follow up are needed.