Mylène Jansen

22 Chapter 2 Study selection All clinical studies where surgical KJD was applied for treatment of knee OA were eligible. One author (MPJ) selected all titles and abstracts that met in- and exclusion criteria. Inclusion criteria were: 1) the population consisted of knee OA patients; 2) treatment with KJD; 3) reporting the change of at least 1 of WOMAC, VAS pain, KOOS, EQ-5D, radiographic JSW or MRI cartilage thickness between before and after treatment; 4) published or accepted for publication in a peer-reviewed journal or conference abstract of the past 2 years; 5) English or Dutch language. Exclusion criteria were: 1) animal studies; 2) experimental studies; 3) cadaver studies; 4) reviews; 5) editorials; 6) case reports; 7) letters. Analysis A risk of bias analysis, including selective reporting bias, was performed by 1 author (MPJ) in agreement with a second author (SCM). Possible publication bias was assessed as well. Primary outcomemeasures were theWesternOntario andMcMaster Universities Osteoarthritis Index (WOMAC, scale 0 – 100, 100=best), Visual Analogue Scale of pain (VAS pain, scale 0 – 100, 0=best), Knee injury and Osteoarthritis Outcome Score (KOOS, scale 0 – 100, 100=best), EuroQol 5D (EQ - 5D, scale 0 – 1, 1=best), radiographic joint space width (JSW; mm), and MRI cartilage thickness (mm). Other clinical and cartilage-related outcomes found in included articles were analyzed as well. One author (MPJ) extracted data from the articles; investigators were not contacted for confirmation. Heterogeneity was determined with the I 2 -test, where I 2 >75% indicates considerable heterogeneity and no meta-analysis was performed for that parameter. Random effects models were used for all outcome measures. For continuous data the mean difference (MD) and 95% confidence interval (95%CI) were calculated with the inverse variance method. For dichotomous data the risk difference and 95%CI were calculated with the Cochran-Mantal- Haenszel method. No sensitivity analyses were performed. All patient groups that were used as a comparator for KJD in included studies are presented as control groups. Data-analysis was performed according to the Cochrane Handbook for Systematic Reviews of Interventions, using Review Manager 5.3 (The Nordic Cochrane Centre, The Cochrane Collaboration, 2014).