RESUMEN
BACKGROUND: Articular cartilage has complex biological characteristics and high durability; therefore, natural degeneration or trauma may lead to irreversible damage of its structure and function. Repair and treatment of articular cartilage injury is an urgent problem in clinic. OBJECTIVE: To report the most common risk factors for failure of articular cartilage repair and their incidence, and to analyze the most important factors influencing the choice of specific surgical treatment for failure of cartilage repair. METHODS: The relevant articles were searched in PubMed and MEDLINE database from 2007 to 2019. The keywords were “articular cartilage, repair, clinic/clinical failure, surgery” in English. Initially, 343 articles were retrieved, and 38 articles were included for final analysis. RESULTS AND CONCLUSION: (1) Microfracture and mosaicplasty have significant failure rates in the early and middle stages after articular cartilage repair, while autologous chondrocyte implantation (ACI) and osteochondral allograft (OCA) transplantation are two effective methods for articular cartilage repair. (2) For the failure of articular cartilage repair, OCA transplantation might be a safe choice in the past. However, a higher re-failure rate of articular cartilage repair has been found in patients undergoing a failed OCA transplantation. For the patients who have failed ACI or matrix-induced ACI, further treatment with ACI or matrix-induced ACI is acceptable. In addition, patients with a history of subchondral bone marrow stimulation have a higher failure rate of ACI. (3) Treatments for cartilage repair failure depend on the type of surgical failure and area and site of cartilage defect. OCA transplantation is the most reliable method for the treatment of cartilage repair failure in subchondral bone marrow stimulation patients. ACI or matrix-induced ACI have shown acceptable therapeutic effect in patients who have suffered cartilage repair failure. When dealing with cartilage repair failure, special attention should be paid to the conditions of subchondral bone.
RESUMEN
Background & objectives: Articular cartilage defects in the knee have a very poor capacity for repair due to avascularity. Autologous chondrocyte transplantation (ACT) is an established treatment for articular cartilage defects. Animal studies have shown promising results with allogenic chondrocyte transplantation since articular cartilage is non-immunogenic. In addition to being economical, allogenic transplantation has less morbidity compared to ACT. This study was undertaken to compare ACT with allogenic chondrocyte transplantation in the treatment of experimentally created articular cartilage defects in rabbit knee joints. Methods: Cartilage was harvested from the left knee joints of six New Zealand white rabbits (R1-R6). The harvested chondrocytes were cultured to confluence and transplanted onto a 3.5 mm chondral defect in the right knees of 12 rabbits [autologous in 6 rabbits (R1-R6) and allogenic in 6 rabbits (R7-R12)]. After 12 wk, the rabbits were euthanized and histological evaluation of the right knee joints were done with hematoxylin and eosin and safranin O staining. Quality of the repair tissue was assessed by the modified Wakitani histological grading scale. Results: Both autologous and allogenic chondrocyte transplantation resulted in the regeneration of hyaline/mixed hyaline cartilage. The total histological scores between the two groups showed no significant difference. Interpretation & conclusions: Allogenic chondrocyte transplantation seems to be as effective as ACT in cartilage regeneration, with the added advantages of increased cell availability and reduced morbidity of a single surgery.