Mylène Jansen

168 Chapter 9 Abstract Background : Knee joint distraction (KJD) has shown clinical efficacy and cartilage restoration in several clinical osteoarthritis (OA) studies. Recently, a user-friendly dedicated KJD frame was developed (KneeReviver) and a prospective multicenter clinical trial was started to evaluate this frame. The goal of this interim analysis was primarily to evaluate its 1-year clinical efficacy and secondarily to evaluate non-inferiority with respect to the previously used frame (Dynamic Monotubes). Methods: 65 young (<65 years) severe knee OA patients received KJD with the KneeReviver in 5 hospitals. Data of 39 patients previously treated with Dynamic Monotubes was available, so in this interim analysis 1-year data of 39 KneeReviver patients was used (1:1 ratio). Sample size calculations showed this was enough for both objectives. Before and 1 year after treatment, patients filled out the WOMAC questionnaire and standardized radiographs were taken to measure joint space width (JSW). Changes over time were calculated with paired t -tests. Non- inferiority limits were 10 for the WOMAC and 0.56 for JSW, based on literature and on no deterioration, respectively. Results: The total WOMAC, all subscales (all >27 points; p< 0.001) and JSW (0.4 mm; p= 0.013) showed significant improvement in KneeReviver patients. The change in total WOMAC (difference 1.3; 95% confidence interval -6.6 to 9.2) and JSW (-0.20; -0.52 to 0.13) were non-inferior for the KneeReviver. Corrected for baseline, the change in JSW was non-inferior (-0.06; -0.35 to 0.24) while the WOMAC change was inconclusive (-7.5; -14.9 to -0.1). Conclusion : KJD with the KneeReviver results in significant clinical efficacy, comparable to that with Dynamic Monotubes.