SAT0572 Initial structural response predicts long-term survival of knee joint distraction as a treatment for knee osteoarthritis

Background In relatively young patients with end-stage knee osteoarthritis (OA), total knee arthroplasty (TKA) comes with the risk of revision surgery1. Knee joint distraction (KJD) is a joint preserving surgery technique, which has been shown to provide clinical and structural improvement for at least five years2 and postpones the need for TKA. Objectives To evaluate long-term clinical and structural results and identify characteristics predicting survival of the native knee joint after KJD. Methods End-stage tibiofemoral OA patients (n=20; age Results Three patients withdrew consent. Survival 9 years after treatment was 48%. Survival percentages differed significantly for gender (women 14%, men 70%; p=0.035; figure 1A) and for increase in minimum JSW in the 1 st year ( 0.5 mm increase 72%; p=0.002; figure 1B). Survivors reported clinical improvement compared to baseline: ΔWOMAC+29.9 points (95% CI +16.9 to+42.9; p=0.001; figure 1C), ΔVAS −46.8 mm (95% CI −31.6 to −61.9; p Gender and minimum JSW increase after 1 year predict survival of the native knee joint after 9 years (OR of 14 and 0.02; both p Conclusions Joint distraction for end-stage knee OA shows long-lasting clinical and structural improvement with a survival of 48% at 9 years. Clinical scores in patients failing treatment were still improved compared to baseline and cannot fully explain the subsequent TKA surgery. Positive predicting factors for survival of the native knee are male gender and a larger initial increase in minimum JSW (both, 70% survival at 9 years). Potentially, an initial decrease in bone density and an increase in mean cartilage thickness are predictive as well. Overall, the initial structural response after KJD appears to be important for long-term success of the treatment. References [1] Kurtz SM, et al. Clin Orthop Relat Res2009;467(10):2606–12. [2] J-TAD van der Woude, et al. Cartilage2017;8(3):263–271. Disclosure of Interest None declared