title: Estimation of the mechanical property of meniscus using ultrasound: examinations of native meniscus and effects of enzymatic digestion.
abstract: We previously developed a novel ultrasound assessment system featuring wavelet transform to evaluate the material properties of articular cartilage. We aimed in this study to demonstrate the feasibility of quantitative evaluation of meniscus using ultrasound and to elucidate the relationships between its acoustic, mechanical, and biochemical properties. Meniscal disc specimens from mature pigs were assessed by ultrasound and compression testing, and their correlation was analyzed. A positive correlation was found between the ultrasound signal intensity and apparent Young's modulus (r=0.61). Subsequently, the porcine meniscal discs were treated with various enzymes and then characterized by ultrasound, by compression tests, by biochemical analyses, and by histology and immunohistochemistry. The signal intensity was decreased not by hyaluronidase but by collagenase treatment. Hyaluronidase-treated menisci showed a discrepancy between acoustic and mechanical properties, suggesting that the ultrasound reflection could not detect a reduction in proteoglycan content. Also, ultrasound signal intensity could only reflect superficial layers of the material. Several limitations exist at present, and further studies and improvements of the device are required. However, given the noninvasive nature and the requirement of only small equipment, this ultrasound assessment system will be an instrumental diagnostic tool for meniscal function in both research and clinical fields.
authors.affiliation: Department of Orthopaedic Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Ko
authors.initials: K
authors.lastname: Yasura
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Mizuno
authors.forename: Yasuaki
authors.initials: Y
authors.lastname: Nakagawa
authors.forename: Koji
authors.initials: K
authors.lastname: Mori
authors.forename: Makoto
authors.initials: M
authors.lastname: Takenaka
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ohashi
authors.forename: Keisuke
authors.initials: K
authors.lastname: Yamada
authors.forename: Masahiko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Keiji
authors.initials: K
authors.lastname: Ando
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kuroki
authors.forename: Takashi
authors.initials: T
authors.lastname: Suzuki
authors.forename: Ken
authors.initials: K
authors.lastname: Ikeuchi
authors.forename: Sadami
authors.initials: S
authors.lastname: Tsutsumi
authors.forename: Takashi
authors.initials: T
authors.lastname: Nakamura
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D017364:Collagenases / Q000494:pharmacology; D019245:Compressive Strength / Q000187:drug effects / Q000502:physiology; D006025:Glycosaminoglycans / Q000378:metabolism; D006821:Hyaluronoglucosaminidase / Q000494:pharmacology; D006909:Hydroxyproline / Q000378:metabolism; D008592:Menisci, Tibial / Q000000981:diagnostic imaging / Q000187:drug effects / Q000502:physiology*; D012212:Rheology / Q000379:methods; D013552:Swine; D014465:Ultrasonics; D014463:Ultrasonography; D014867:Water / Q000378:metabolism
chemical_list: D006025:Glycosaminoglycans; D014867:Water; D006821:Hyaluronoglucosaminidase; D017364:Collagenases; D006909:Hydroxyproline