AIM:In case of refractory knee osteoarthritis at a relatively young age causing persisting pain, treatment options are limited. In case of medial degeneration high tibial osteotomy (HTO) may be considered, or in case of more generalized OA, a total knee prosthesis (TKP). However, these young and active patients have a major risk of revision surgery. Knee joint distraction (KJD) could be an alternative treatment; prolonged clinical benefit and cartilage tissue repair have been demonstrated. Therefore, two RCTs were designed, evaluating clinical efficacy and for HTO additionally comparing cartilage tissue repair. MATERIALS AND METHODS:Patients<65 years of age considered in regular clinical practice for TKP or HTO were included. TKP and HTO were performed according to usual standard of care. KJD was performed for six continuous weeks by use of an external fixator bridging the joint, fixed at each side to two bone pins. RESULTS: Inclusion rate was stable over time and took 42 and 22 months for TKP vs KJD and HTO vs KJD, respectively. At baseline, patient characteristics differed: age was 55.2±0.9 and 50.0±0.7 p<0.000, KOOS-score was 36.6±1.4 and 42.2±1.6 p=0.012, and VAS-pain was 68.7±2.1 and 61.4±2.4 p=0.028, in the KJD-TKP cohort and KJD-HTO cohort, respectively. CONCLUSIONS: For implementation of KJD a comparison with available surgical alternatives is needed. TKP and HTO were chosen as the most relevant comparators. Inclusion is closed, and all treatments are completed. Data have to be awaited to determine the position of KJD in surgical treatment of refractory knee OA.