Related Experiment Video
Updated: Apr 27, 2026
Establishment and Evaluation of a Sheep Model of Full-thickness Osteochondral Defect
Published on: April 14, 2026
Sonographic evaluation of knee cartilage defects implanted with preconditioned scaffolds
Sleiman R Ghorayeb1, Adam Levin2, Michael Ast2
1School of Engineering and Applied Sciences, Ultrasound Research Laboratory, Hofstra University, Hempstead, New York USA (S.R.G.); Department of Orthopedic Surgery, North Shore-LIJ Health System, Great Neck, New York USA (A.L., M.A.); and Orthopedics Research Laboratory, Feinstein Institute for Medical Research, North Shore Hospital, Manhasset, New York USA (S.R.G., J.A.S., D.A.G.). sghoraye@nshs.edu sleiman.r.ghorayeb@hofstra.edu.
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.
