Osteochondral Biopsy Analysis Demonstrates That BST-CarGel Treatment Improves Structural and Cellular Characteristics of Cartilage Repair Tissue Compared With Microfracture. (January 2016)

• Record Type: Journal Article
• Authors: Méthot, Stéphane; Changoor, Adele; Tran-Khanh, Nicolas; Hoemann, Caroline D.; Stanish, William D.; Restrepo, Alberto; Shive, Matthew S.; Buschmann, Michael D.
• Is Part Of: Cartilage. Volume 7:Number 1(2016)
• Page Start: 16
• Page End: 28
• Publication Date: 2016-01
• Subjects: cartilage repair -- biopsy -- histology: scoring systems -- polarized light microscopy -- collagen organization; Cartilage -- Periodicals; 616.7
• DOI: 10.1177/1947603515595837
• Languages: English
• ISSNs: 1947-6035

Abstract

Objective: The efficacy and safety of BST-CarGel, a chitosan-based medical device for cartilage repair, was compared with microfracture alone at 1 year during a multicenter randomized controlled trial (RCT) in the knee. The quality of repair tissue of osteochondral biopsies collected from a subset of patients was compared using blinded histological assessments. Methods: The international RCT evaluated repair tissue quantity and quality by 3-dimensional quantitative magnetic resonance imaging as co-primary endpoints at 12 months. At an average of 13 months posttreatment, 21/41 BST-CarGel and 17/39 microfracture patients underwent elective second look arthroscopies as a tertiary endpoint, during which ICRS (International Cartilage Repair Society) macroscopic scoring was carried out, and osteochondral biopsies were collected. Stained histological sections were evaluated by blinded readers using ICRS I and II histological scoring systems. Collagen organization was evaluated using a polarized light microscopy score. Results: BST-CarGel treatment resulted in significantly better ICRS macroscopic scores ( P = 0.0002) compared with microfracture alone, indicating better filling, integration, and tissue appearance. Histologically, BST-CarGel resulted in a significant improvement of structural parameters— Surface Architecture ( P = 0.007) and Surface/Superficial Assessment ( P = 0.042)—as well as cellular parameters— Cell Viability ( P = 0.006) and Cell Distribution ( P = 0.032). No histological parameters were significantly better for the microfracture group. BST-CarGel treatment also resulted in a more organized repair tissue with collagen stratification more similar to native hyaline cartilage, as measured by polarized light microscopy scoring ( P = 0.0003). Conclusion: Multiple and independent analyses in this biopsy substudy demonstrated that BST-CarGel treatment results in improved structural and cellular characteristics of repair tissue at 1 year posttreatment compared with microfracture alone, supporting previously reported results by quantitative magnetic resonance imaging.