A tissue engineering-based approach has become a possible solution for the treatment of chondral lesions. Actually, autologous chondrocytes seeded on biodegradable scaffolds for cell proliferation were successfully developed. However, these techniques promote cartilaginous but not bony regeneration. Therefore a new experimental approach involving mesenchymal stem cells (MSC) has been introduced. A 31-year-old man affected by massive osteonecrosis of the right femoral head was selected to begin this study. The MSC were isolated from the bone marrow harvested from the patient’s iliac crest. After a 3-week monolayer expansion, cells were seeded and cultured onto hyaluronan-based three-dimensional scaffolds and DBM spongy chips, used to regenerate the cartilaginous and the bony portion, respectively. After a 2-week cultivation, constructs were implanted inside the osteochondral defect using the transtrochanteric approach under arthroscopic control. The patient underwent clinical, X-ray and MRI control during the first 6 months after operation. Pluripotent MSC may be a promising strategy for osteochondral defect reconstruction due to their capacity to differentiate in vivo along chondrocytic and osteoblastic lineages. This ability, combined with two different kinds of three-dimensional scaffolds, permits simultaneous bone and cartilage tissue regeneration. The preliminary results are encouraging but a more precise judgement of the effectiveness of this method requires longer follow-up.
Autologous chondrocyte transplantation has become a possible solution for the treatment of chondral knee lesions. In the last years matrix autologous chondrocyte transplantation procedures were developed by various scientists. We selected a biodegradable, hyaluronian-based biocompatible scaffold for cell proliferation. This nonwoven three-dimensional structure consists of a network of 20 – B5-thick fibers with interstices of variable sizes which constitute an optimal physical support to allow cell-cell contacts, cluster formation, and extracellular matrix deposition in order to create a bioengenerized cartilage Hyalograft C. The easy handling of Hyalograft C in open surgery has suggested us to investigate its possible use by an arthroscopic procedure. Arthroscopic technique has been used from December 2000 in 88 cases. At December 2003 45 patients achieved at least 1 year follow up and 22 patients – 2 years follow up. All the patients were clinically evaluated was analyzed according to the International Repair Cartilage Society score at 12 and 24 months. Returning back to sport was also recorded. We were able to obtain CT scans or MRI images for all patients at 6, 12 and 24 months of follow up. No complications related to the implant and no serious adverse events were observed during the treatment and follow up period. The IKDC objective score improved after 12 months in all patients, showing a normal or nearly normal knee in 96,7% of patients. The mean IKDC subjective score obtained was 41,3 at baseline, 76.9 at the 12 months follow-up control, and 75,9 after 24 months. The worsening of IKDC score was noted in 1 of 22 patients analyzed at 12 and 24 months follow up. A second look arthroscopy was performed in 11 patients at 12 months follow up and a complete healing of the defect and the excellent quality of regenerated cartilage was noted at macroscopic examination. The histological evaluation in 6 cases has demonstrated the hyaline type of new cartilage, although not completely mature. This matrix autologous chondrocyte transplantation procedure avoids the use of periosteal flap, simplify the surgical procedure and permit to perform the arthroscopic implant. Thus, complications as hypertrophy or ossification of periosteal flap are avoided and the surgical morbidity and the recovery time for the patient are extremely reduced. The preliminary clinical and histological results are encouraging but the decree absolute on the efficiency of this method will be assessed at longer follow up.
