Abstract
Background: The purpose of this prospective study is to analyse the histological results of the treatment of deep chondral defects with autologous chondrocyte transplantation in patients with articular cartilage defects of the knee joint.
Methods: Patients with articular cartilage defects of the knee joint were recruited prospectively and underwent autologous chondrocyte transplantation. Chondrocytes from a non-weight bearing area of the knee were harvested, isolated and cultured in vitro. Subsequent reimplantation involved injection of the chondrocytes into the defect which was then sealed with a porcine IIIII collagen membrane. Postoperatively, patients were evaluated at one year by clinical assessment, arthroscopy and histological examination. The presence of hyaline cartilage in the transplanted region was determined by staining with Erlich’s H & E, Safranin 0 and polarised light microscopy and by imimmohistochemical analysis with S100. Confirmation of the presence of hyaline cartilage was further assessed by examination of Type 11 collagen messenger RNA expression using PCR.
Results: Thirty four patients were recruited between July 1998 and November 2001, with a median age of 31 years (range 15–51 years). Of the 34 patients treated, 17 had right-sided lesions, 15 had left-sided lesions and two patients had bilateral lesions. Solitary lesions were treated in 36 knees with two defects being treated in one knee (37 defects in total). The defects were located on the medial femoral condyle in 22 cases, the lateral femoral condyle in eight, the trochlea in two and the patella in five cases. The defect size ranged from 1–7 cm2 (mean area 2.88cm2). The follow-up of the patients ranged from 1–39 months (mean 19 months). Twenty five patients had at least one-year follow-up. Of these patients, using the BritIberg Rating, six patients had excellent results, with 11 good, six fair and two poor. The mean Lysholin and GilIquist scores improved from 44.7 pre-op to 76.2 one-year post-op and the mean Verbal Numerical Pain Scores improved from 7.1 to 1.1. 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 13 out of 19 cases (70%).
Conclusion: Although long-term follow-up is currently unavailable, 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 Mr Roger Smith. Correspondence should be addressed to him care of the British Orthopaedic Association, Royal College of Surgeons, 35-43 Lincoln’s Inn Fields, London WC2A 3PN.
