[Treatment of patellar cartilage defects by solid chondral graft: first experience]

To present the results of a new method for treatment of cartilage defects of the patella, using a solid graft produced by chondrocytes on a three-dimensional matrix.

Chondrocyte transplantation is indicated in deep and extensive chondral and osteochondral defects of all large joints in patients at 18 to 40 years of age. When, on arthroscopic examination, a defect of patellar cartilage was found, healthy cartilage was collected from a non-weight-bearing surface, i. e., the intercondyllar fossa. In the tissue bank, the cartilage was fragmented, chondrocytes were isolated enzymatically and cultivated in vitro under a permanent assessment for cell quality. The cultivation period ranged from 15 to 35 days. Subsequently, a solid graft was prepared with the use of Tissucol glue, a three-dimensional matrix. The graft was transplanted after arthroscopic verification of the defect by an open, minimally invasive procedure with tourniquet application, with the patient receiving antibiotics. The result of chondral graft implantation was checked by second-look arthroscopy involving removal of a small sample of the integrated chondral graft taken for histological and morphological examination. Another method of post-operative assessment was examination by magnetic resonance imaging (MRI). Solid chondral graft transplantation was used in three patients (two men and one women) treated in the Department of Orthopedics, University Hospital Brno, between May 2001 and December 2003. Their average age at the time of surgery was 31 years (range, 27 to 38 years). The average follow-up was 22 months (range, 2 to 33 months). The post-operative stage of he cartilage was assessed by MRI in one patient and by second-look arthroscopy also in one patient.

Two patients fully resumed their daily activities, sports including, at 6 months after the treatment, with one reporting mild chondropathic problems and the other being without complaints. In the third patient at 2 months after surgery, the treatment had not been completed yet. The patella examined by MRI at 18 months after surgery showed a confluent, high layer of hyaline cartilage covering the articular surface. Second-look arthroscopy and histological examination also revealed healthy hyaline cartilage. No serious complications were recorded.

Autologous chondrocyte transplantation is indicated in younger, active patients with cartilage defects exceeding 2 cm2 and in patients undergoing revision surgery for any defect. The success rate of this procedure has been reported to be over 90 %. One year after transplantation, the cartilage had characteristics of a healthy tissue, as assessed by MRI. Biopsy examination showed that the grafts, chondrocytes as well as osteocytes maintained their integrity at 2 to 12 months after surgery.

The aim of this paper was to define and check indications, to develop the surgical technique, to improve post-operative management and to evaluate mid-term results of the treatment of cartilage defects on the patella.