Clinical application of scaffolds for cartilage tissue engineering

The purpose of this paper is to review the basic science and clinical literature on scaffolds clinically available for the treatment of articular cartilage injuries. The use of tissue-engineered grafts based on scaffolds seems to be as effective as conventional ACI clinically. However, there is limited evidence that scaffold techniques result in homogeneous distribution of cells. Similarly, few studies exist on the maintenance of the chondrocyte phenotype in scaffolds. Both of which would be potential advantages over the first generation ACI. The mean clinical score in all of the clinical literature on scaffold techniques significantly improved compared with preoperative values. More than 80% of patients had an excellent or good outcome. None of the short- or mid-term clinical and histological results of these tissue-engineering techniques with scaffolds were reported to be better than conventional ACI. However, some studies suggest that these methods may reduce surgical time, morbidity, and risks of periosteal hypertrophy and post-operative adhesions. Based on the available literature, we were not able to rank the scaffolds available for clinical use. Firm recommendations on which cartilage repair procedure is to be preferred is currently not known on the basis of these studies. Randomized clinical trials and longer follow-up periods are needed for more widespread information regarding the clinical effectiveness of scaffold-based, tissue-engineered cartilage repair

REPAIR OF SHEEP ARTICULAR-CARTILAGE DEFECTS WITH A RABBIT COSTAL PERICHONDRIAL GRAFT

A xenograft of costal rabbit perichondrium was transplanted to an articular cartilage defect in a sheep knee. After 12 weeks, cartilage was formed with increased calcification of the basal layer and a mean of 74 percent collagen type 11. The synovium did not show any infiltration, indicating the absence of any immunologic reaction

A retrospective analysis of two independent prospective cartilage repair studies: autogenous perichondrial grafting versus subchondral drilling 10 years post-surgery

Background: Experimental data indicate that perichondrial grafting to restore articular cartilage defects will result in repair with hyaline-like cartilage, In contrast, debridement and drilling results in repair with fibro-cartilage. In this retrospective study the long-term clinical results of both procedures were compared to evaluate the theoretical benefit of repair with hyaline-like tissue. Methods: From two independent studies patients were selected with a cartilage defect in their knee. The selection was performed using strict inclusion criteria published elsewhere [Bouwmeester et at. Int. Orthop. 21 (1997) 313], The patients were treated with either a perichondrium transplantation (PT group, n = 14) or with an 'open' debridement and drilling procedure (DID group, n = 11). The results of both procedures after 10-11 years were evaluated using the Hospital for Special Surgery Knee Score (HSSS), X-ray examination, clinical examination and visual analogue scales (VAS) for pain during walking and at rest. Results: Both procedures resulted in a general improvement compared to the situation before the operation. After an average of 10 years in the PT group there were three failures. in the DID group none, success rates were 78% and 100%, respectively. When comparing the successful PT patients with the DID patients. there were no differences in HSSS and VAS data. Both groups showed an equal number of irregular operation surface sites on X-ray (PT 9/11 versus DID 8/10). Conclusions: This study shows that clinically at 10 years follow-up no difference was observed between debridement and drilling and perichondrium transplantation for treatment of an isolated cartilage defect. This raises questions about ongoing research to develop methods in order to improve the results of debridement and drilling as therapy for an isolated cartilage defect in a young patient (less than or equal to40 years). (C) 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved