Sonographic evaluation of knee cartilage defects implanted with preconditioned scaffolds

Sleiman R. Ghorayeb, Adam Levin, Michael Ast, John A. Schwartz, Daniel A. Grande

Research output: Contribution to journalArticlepeer-review


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 (R2 = 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.

Original languageEnglish (US)
Pages (from-to)1241-1253
Number of pages13
JournalJournal of Ultrasound in Medicine
Issue number7
StatePublished - Jul 1 2014
Externally publishedYes


  • Articular cartilage
  • Knee arthrotomy
  • Knee repair
  • Musculoskeletal ultrasound
  • Osteochondral defects
  • Scaffold
  • Sonography of cartilage

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging


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