title: Sonographic evaluation of knee cartilage defects implanted with preconditioned scaffolds.
abstract: OBJECTIVE
  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.
authors: School 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.
authors: Sleiman R
authors: SR
authors: Ghorayeb
authors: School 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.).
authors: Adam
authors: A
authors: Levin
authors: School 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.).
authors: Michael
authors: M
authors: Ast
authors: School 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.).
authors: John A
authors: JA
authors: Schwartz
authors: School 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.).
authors: Daniel A
authors: DA
authors: Grande
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000000981:diagnostic imaging* / Q000293:injuries / Q000473:pathology*; D005109:Extracellular Matrix; D015316:Genetic Therapy; D007719:Knee Joint / Q000000981:diagnostic imaging* / Q000601:surgery; D011817:Rabbits; D054457:Tissue Scaffolds; D014463:Ultrasonography
keywords: articular cartilage; knee arthrotomy; knee repair; musculoskeletal ultrasound; osteochondral defects; scaffold; sonography of cartilage