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Sonographic Evaluation of Knee Cartilage Defects Implanted With Preconditioned Scaffolds
Author(s) -
Ghorayeb Sleiman R.,
Levin Adam,
Ast Michael,
Schwartz John A.,
Grande Daniel A.
Publication year - 2014
Publication title -
journal of ultrasound in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 91
eISSN - 1550-9613
pISSN - 0278-4297
DOI - 10.7863/ultra.33.7.1241
Subject(s) - fibrocartilage , medicine , scaffold , extracellular matrix , hyaline cartilage , biomedical engineering , cartilage , stromal cell , hyaline , in vivo , matrix (chemical analysis) , bone morphogenetic protein , anatomy , nuclear medicine , pathology , articular cartilage , osteoarthritis , materials science , microbiology and biotechnology , biochemistry , chemistry , alternative medicine , gene , composite material , biology
Objectives The purpose of this study was to develop a novel method for creating an acellular bioactive scaffold, to prove its efficacy in vivo and in vitro for the augmentation of biological repair, and to confirm that sonographic microscopy is a viable modality for monitoring the healing process of osteochondral defects implanted with preconditioned bioactive scaffolds. Methods Rabbit marrow stromal cells were retrovirally transduced with either bone morphogenetic protein 7 (BMP‐7) or insulinlike growth factor 1 (IGF‐1) genes, cultured for 9 weeks in nonwoven poly‐L‐lactic acid scaffolds, and then frozen and lyophilized. The knees were evaluated at 3, 6, and 12 weeks after surgery using 20‐MHz ultrasound and then prepared for routine histologic analysis. B‐scans of the extracellular matrix defects were compared to histologic results. Results Control defects showed a void or a mixture of fibrocartilage tissue. Both types of scaffolds resulted in a higher percentage (both P < .001) of primarily hyaline cartilage tissue with intact articular surfaces. The osteochondral defects were clearly observed in each sonographic signature. There were no differences between images of scaffolds treated with IGF‐1 or BMP‐7. Extracellular matrix regrowth was found to closely parallel ( R 2 = 0.968; P < .003) the histologic images. A 3‐mm defect depth and a 2.5‐mm scaffold thickness were measured on the sonograms, comparing well to actual dimensions. Conclusions There was a gradual increase in healing bordering the defects for the 3‐, 6‐, and 12‐week samples. Also, we have shown that sonography can aid in monitoring implantation of preconditioned scaffolds in osteochondral defects and thus assessing the healing process and cartilage/bone quality.