This study investigated the effects of EndoCert certification on outcome quality after hip and knee replacement surgery in Germany. The analysis was based on three data sets: AOK billing data, structured hospital quality reports and EndoCert data.Certified endoprosthesis centres (EPZ) were compared with non-certified clinics with regard to the primary endpoint overall complications. The effects of certification were investigated using hierarchical logistic regression models. A total of 1283 clinic locations were identified that performed study-relevant revision surgery during the observation period (2016-2018).The results showed significantly fewer overall complications during hip replacement surgery in certified centres compared to non-certified facilities (OR =0.83 [95% CI: 0.75-0.92]; p=0.0003). No significant difference was found for knee replacements (OR =1.09 [95% CI: 0.93-1.27]; p=0.29).This study provides important insights into quality assurance in arthroplasty. The positive effects of EndoCert certification for hip replacements underline the importance of specialized centres for complex interventions and targeted certification measures in improving the quality of care. The lack of effects for knee replacements could be due to limitations of the quality indicator used, as possible improvements in mobility and freedom from pain were not taken into account. Further studies are therefore required.