Abstract
Lesions to articular cartilage have a poor capability of regeneration and by mechanical wear and enzymatic digestion they may progress to osteoarthritis. In Sweden more than 900 patients with chondral or osteochondral lesions have been treated with autologous chondrocyte transplantation (ACT) since 1987. Cartilage is harvested arthroscopically and the chondrocytes are isolated. After two weeks of culturing the chondrocytes are deposited in the cartilage lesion in a cell suspension. The chondrocytes start to produce matrix and gradually form new hyaline cartilage able to withstand the forces of the knee.
Lesions to the femoral condyles have shown the most promising results when treated with ACT (90% Good/Excellent, n=57), osteochonditis dissecans showed 84% Good/Excellent results (n=32), multiple knee joint lesions 75% Good/Excellent (n=53) and femoral condyle lesions with anterior cruciate ligament reconstruction 74% Good/Excellent (n=−27) at a long term follow up (2–11 years). The outcome after patella lesions treated with ACT were initially not as good (2 of 7 patients were graded Good or Excellent at a mean follow-up of 36 months) but better understanding of the nature of patellar lesions and development of the surgical technique have improved the result (65% Good or Excellent, n=32). Patients treated with ACT for cartilage lesion to the femoral trochlea showed Good/Excellent results in 58% (n=12).
At a second look arthroscopy biopsies were taken in 37 patients. In 80% of the biopsies the repair tissue was classified as hyaline like cartilage. Immunohistochemical analysis of collagen II, aggrecan and comp showed ++ to +++ for the hyaline like repair tissue compared to +++ for normal cartilage. There were also a strong correlation (0.73) between hyaline like repair and Good/ Excellent results.
Other areas have been transplanted as well such as the tibial plateau, the talus and the head of the humerus, but due to the small numbers of patients and short follow-up ACT to these areas is not yet recommended.
The clinical outcome after treating chondral and osteochondral lesions in the knee is good at a long term follow-up and the repair tissue is histological similar to normal articular cartilage.
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
