Cartilage cell transplantation (ACT)

Complete replacement with your body's own cartilage tissue
Modern cartilage therapy in the hands of the specialists
Matrix-coupled autologous chondrocyte transplantation (M-ACT) is one of the current therapeutic procedures for higher-grade symptomatic cartilage damage (grades 3 and 4) of a certain size (up to 10 cm2, best results 2-6 cm2). It has very good long-term results. Initially local cartilage damage often results in progressive, extensive arthrosis and the threat of joint replacement. Local cartilage damage occurs both in young patients (traumatic, osteochondrosis dissecans, leg axis defects...) and in older patients (local overload, trauma) and requires detailed analysis. The aim must be to understand the underlying mechanism.
It is crucial that the attending physician has access to all therapy options. Only then is he free to make decisions and can choose the right procedure for you together with you. The certification as a knee surgeon by the German Society for Knee Surgery stands precisely for this specialisation and competence.
At Orthozentrum Freiburg we offer the entire spectrum of conservative and surgical therapy options for the knee joint. If, after a targeted diagnosis and exhaustion of the conservative therapy options (physiotherapy, targeted muscle building, insoles, possibly infiltration with hyaluron / ACP, acupuncture), surgical intervention is necessary, autologous cartilage cell transplantation (ACT) is the only option to fill a localised cartilage damage with your own cartilage tissue.
During the first arthroscopic procedure (knee endoscopy, defect documentation/measurement), two to three small cartilage bone cylinders are taken from non-weight-bearing regions of your knee joint. These are sent under strict instructions to a special laboratory where they are cultivated and multiplied over the course of 6-8 weeks. The subsequent transport back to your surgeon takes place within hours in special refrigerated containers. Depending on the manufacturer, your cartilage cells are sewn into a membrane or so-called spheroids (cartilage islands) are inserted into the defect. Beforehand, the defect must be exposed via a small skin incision and the edges prepared (mini open procedure).
Diese Methode ermöglicht es, einen umschrieben Knorpeldefekt mit Ihrem eigenen Knorpelgewebe vollständig aufzufüllen. Ihr Knie- oder Sprunggelenk hat bei erfolgreicher Therapie eine nahezu normale Prognose bezüglich der Entwicklung einer Arthrose. Durch diese Technik kann in vielen Fällen ein Fortschreiten der Knorpelschäden und somit ggf. ein Teilersatz / Ersatz des Gelenkes vermieden werden. Entscheidend für den Erfolg ist die korrekte, leitliniengerechte Indikationsstellung. Grundvoraussetzung sind ein stabiles Gelenk sowie die Adressierung von dem Knorpelschaden zugrundeliegenden knöchernen Pathologien (Achsenfehlstellungen). Die besten Ergebnisse haben Knorpeldefekte im Bereich der Oberschenkelrolle, gefolgt vom oberen Sprunggelenk, des Kniescheibengleitlagers sowie des Unterschenkelplateaus. Nach der Transplantation folgt eine intensive Phase der Physiotherapie nach einem speziellen Nachbehandlungsschema sowie die regelmäßige Kontrolle in der Sprechstunde. Alternativ können bei kleineren Knorpelschäden (<3 cm2) knorpelstimulierende Verfahren (Mikrofrakturierung, AMIC) eingesetzt werden. Diesbezüglich gibt das MRT bereits die wichtigsten Hinweise vor der Operation. Lassen Sie sich ausführlich und individuell beraten.
Author: Tarek Schlehuber, MD
As successor to Dr Volker Fass at the Orthozentrum and senior physician for sports orthopaedics at the Lorettokrankenhaus Freiburg, Dr Schlehuber treats patients from near and far for pathologies of the lower extremity. As a certified knee surgeon of the DKG and an active member of the working group for arthroscopy, he combines tried and tested with innovative techniques. In 2018, he himself had to undergo a major operation on the knee joint (conversion osteotomy) and found this change of perspective formative for his further professional activity.