Dr. Zinser is performing cartilage Repair since 1997; when he did his first ACI with periostal flap covering. As a former elite-athlete in Triple-Jump (Best Mark 17.33m) he still treats a lot of athletes in his department. Since 1997 he treated more than 600 Patients with different ACI-procedures in knee-; ankle- an also hip-joint. In 2009 he was a founding member of the QKG e.V = Qualitätskreis Knorpel-Repair und Gelenkerhalt e.V. (= Quality-Circle for Cartilage-Repair and Joint-Preserving) in Germany wherin he still serves as chairman. More Information about aims and work of QKG e. V. on www.qkg-ev.de . This Group has an overview over more than 3000 ACIs (different techniques and matrices) on several joints and thousands of other cartilage repair procedures and joint-preserving procedures in knee-; hip- ankle-joint and other joints. Dr. Zinser is Head of Department in the "Klinik für Orthopädie und Unfallchirurgie" in Dinslaken. The Clinic was honoured as an Center of Excellence and hospitation center for joint preserving procedures and therapies.