Abstract
Introduction: Articular cartilage defects within the knee joint have poor capacity for repair. The purpose of this study is to analyse the short-term clinical and histological results of the treatment of deep chondral defects with autologous chondrocyte transplantation.
Methods: This is a prospective study involving twenty-two consecutive patients receiving autologous chondrocyte transplantation. Chondrocytes from a non weight bearing area of the knee are harvested, then isolated and cultured in vitro. Re-implantation involves injection of the chondrocytes into the defect which is then sealed with a porcine I/III collagen membrane. Evaluation consists of clinical assessment, arthroscopy and histological examination. Histological evaluation consists of examination of a biopsy of the transplanted area one-year post-op. Staining techniques include the use of Erlich’s H & E, Safranin O and S100. Using polarised light, the absence of the fibrillar nature of fibrocartilage confirms the presence of hyaline cartilage. Further confirmation can be gained by the examination of messenger RNA content, confirming the presence of type II collagen.
Results: The patients were treated between July 1998 and December 2000. The age range of the patients was 15–51 years (mean age 31 years). Of the 22 patients treated, 13 had right-sided lesions, 11 had left-sided lesions with two patients receiving bilateral procedures. Solitary lesions were treated in 23 knees with two defects being treated in one knee (25 defects in total). The defects were located on the medial femoral condyle in 17 cases, the lateral femoral condyle in five, the trochlea in two and the patella in one case. The defect size ranged from 1–5.4cm2 (mean area 2.65cm2). The follow-up of the patients ranges from 3-30 months (mean 16 months). Thirteen patients have at least one-year follow-up. Of these patients, using the Brittberg Rating, two patients have excellent results, with six good, four fair and one poor. The mean Lysholm and Gillquist scores improved from 50 pre-op to 72 one-year post-op and the mean Verbal Numerical Pain Scores improved from 7.2 to 2.6. Arthroscopy revealed that the transplants were level with the surrounding surface in most cases. Biopsy at one year confirmed the presence of hyaline cartilage in 10 out of 13 cases.
Conclusion: Although the results are short-term, autologous chondrocyte transplantation can provide, with careful patient selection and meticulous surgical technique, an effective treatment for cartilage defects of the knee. The histological results are extremely encouraging and chondrocyte transplantation may be the only procedure to allow regeneration of hyaline cartilage.
The abstracts were prepared by Professor Jegan Krishnan. Correspondence should be addressed to him at the Flinders Medical Centre, Bedford Park 5047, Australia.
