P168 - Knee Joint Distraction As Standard Of Care Treatment For Knee Osteoarthritis: A Comparison With Clinical Trial Patients

Corresponding Author
E.C. Kester, no significant relationships; F.P.J.G. Lafeber, cofounder and co-director ArthroSave BV; M.D. van Empelen, no significant relationships; M.P. Jansen, no significant relationships; R.J.H. Custers, no significant relationships; S.C. Mastbergen,
Presentation Topic
Poster Rating



Knee joint distraction (KJD) has been evaluated as a joint-preserving treatment to postpone total knee arthroplasty (TKA) in knee osteoarthritis (OA) patients in several clinical trials including one open prospective study (OPS) and two randomized controlled trials (RCTs). Since 2014, KJD is a standard of care treatment in several Dutch hospitals. This study compares baseline characteristics and clinical outcome at one year post-treatment of KJD patients treated in regular care vs study conditions.

Methods and Materials

In the OPS, 20 patients were treated with KJD for eight weeks. In two RCTs, 41 patients (n=19,KJD vs TKA; n=22,KJD vs HTO) were treated with KJD for six weeks. 84 patients were treated with six-week KJD in regular care and available for one-year follow-up (2014-2017). All distraction surgeries were performed using two external fixators with built-in springs. The knee was distracted 5 mm and weight-bearing was supported. WOMAC questionnaires were assessed at baseline and twelve months to evaluate clinical efficacy. Only regular care patients who completed both questionnaires were included in analyses.


In daily practice, 41 patients completed both questionnaires. Baseline characteristics for both groups (table 1) show a significant, but small difference in distraction duration. The total WOMAC score and subscales for both groups increased statistically and clinically (>15 points) significantly at one year compared to baseline (figure 1). There were no significant differences between regular care and clinical trial patients (when corrected for baseline WOMAC and distraction duration; all p>0.068).



In regular care KJD, results in a statistically and clinically significant one-year improvement in total WOMAC and subscales, similar to results in found in clinical trials. Longer follow-up is needed to confirm long term results. These results support that KJD can be a treatment in regular care and as such can be a joint-preserving treatment of choice for young knee OA patients.