Bilayer Implants

Abstract

Objective. To compare the regenerative capacity of 2 distinct bilayer implants for the restoration of osteochondral defects in a preliminary sheep model. Methods. Critical sized osteochondral defects were treated with a novel biomimetic poly-ε-caprolactone (PCL) implant (Treatment No. 2; n = 6) or a combination of Chondro-Gide and Orthoss (Treatment No. 1; n = 6). At 19 months postoperation, repair tissue (n = 5 each) was analyzed for histology and biochemistry. Electromechanical mappings (Arthro-BST) were performed ex vivo. Results. Histological scores, electromechanical quantitative parameter values, dsDNA and sGAG contents measured at the repair sites were statistically lower than those obtained from the contralateral surfaces. Electromechanical mappings and higher dsDNA and sGAG/weight levels indicated better regeneration for Treatment No. 1. However, these differences were not significant. For both treatments, Arthro-BST revealed early signs of degeneration of the cartilage surrounding the repair site. The International Cartilage Repair Society II histological scores of the repair tissue were significantly higher for Treatment No. 1 (10.3 ± 0.38 SE) compared to Treatment No. 2 (8.7 ± 0.45 SE). The parameters cell morphology and vascularization scored highest whereas tidemark formation scored the lowest. Conclusion. There was cell infiltration and regeneration of bone and cartilage. However, repair was incomplete and fibrocartilaginous. There were no significant differences in the quality of regeneration between the treatments except in some histological scoring categories. The results from Arthro-BST measurements were comparable to traditional invasive/destructive methods of measuring quality of cartilage repair.

Quantitative Arthroscopic Assessment of Articular Cartilage Quality by Means of Cartilage Electromechanical Properties

“…It has recently been shown that electromechanical assessment of cartilage quality after implantation of bilayer constructs was comparable with evaluation by conventional destructive methods in an in vivo sheep model. 15 Similarly, measurement of cartilage electromechanical properties during routine arthroscopic procedures can help to evaluate the tissue quality before major macroscopic lesions appear. Advantages and limitations of the described technique are discussed in Table 2 .…”

Articular and Artificial Cartilage, Characteristics, Properties and Testing Approaches—A Review

“…Hydrogels are categorized as natural and synthetic and can be modulated with cell-free or cell-laden scaffolds. Some of the cell-free scaffolds have been presented with the use of bacterial nano-cellulose [ 102 ], polyethylene glycol (PEG) in combination with HA [ 103 ], collagen-hydroxyapatite hybrids [ 104 ], aragonite-hyaluronate membranes [ 105 ], acrylamide (AAm) hydrogels [ 106 ], alginate (Alg)/chitosan compounds, agarose/polyglycolic acids (PGA) [ 107 ], and porous polycaprolactone (PCL) [ 108 ]. The mentioned scaffolds were used clinically; however, after clinical follow-up in the longer term, they were rejected due to the lack of strength and durability.…”