title: Optical verification of a technique for in situ ultrasonic measurement of articular cartilage thickness.
abstract: Several investigators have used pulse-echo ultrasonics to measure the thickness of articular cartilage in situ. The underlying assumption in all measurements was that the second reflection used in thickness calculations was from the calcified-cartilage/cartilage boundary (tidemark). To investigate this assumption, the thickness of 24 cartilage plugs excised from a human femoral head was measured both ultrasonically and optically. Measurements established that the second reflection was from the tidemark and validated the ultrasonic technique as a method of mapping the thickness distribution of articular cartilage in synovial joints in situ.
authors.affiliation: Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge 02139.
authors.forename: V E
authors.initials: VE
authors.lastname: Modest
authors.forename: M C
authors.initials: MC
authors.lastname: Murphy
authors.forename: R W
authors.initials: RW
authors.lastname: Mann
mesh_terms: D000077:Acetabulum / Q000033:anatomy & histology; D002358:Cartilage, Articular / Q000033:anatomy & histology*; D005270:Femur Head / Q000033:anatomy & histology; D055095:Optics and Photonics; D014463:Ultrasonography