title: Arthroscopic ultrasound technique for simultaneous quantitative assessment of articular cartilage and subchondral bone: an in vitro and in vivo feasibility study.
abstract: Traditional arthroscopic examination is subjective and poorly reproducible. Recently, we introduced an arthroscopic ultrasound method for quantitative diagnostics of cartilage lesions. Here we describe our investigation of the feasibility of ultrasound arthroscopy for simultaneous measurements of articular cartilage and subchondral bone. Human osteochondral samples (n = 13) were imaged using a clinical 9-MHz ultrasound system. Ultrasound reflection coefficients (R, IRC), the ultrasound roughness index (URI) and the apparent integrated backscattering coefficient (AIB) were determined for both tissues. Mechanical testing, histologic analyses and micro-scale computed tomography imaging were the reference methods. Ultrasound arthroscopies were conducted on two patients. The ultrasound reflection coefficient correlated with the Mankin score and Young's modulus of cartilage (|r| > 0.56, p < 0.05). Ultrasound parameters (R, IRC, AIB) for subchondral bone correlated with the bone surface/volume ratio (|r| > 0.70, p < 0.05) and trabecular thickness (|r| > 0.59, p < 0.05). Furthermore, R and subchondral bone mineral density were significantly correlated (|r| > 0.65, p < 0.05). Arthroscopic ultrasound examination provided diagnostically valuable information on cartilage and subchondral bone in vivo.
authors.affiliation: Department of Applied Physics, University of Eastern Finland, Kuopio, Finland. jukka.liukkonen@uef.fi
authors.forename: J
authors.initials: J
authors.lastname: Liukkonen
authors.forename: J
authors.initials: J
authors.lastname: Hirvasniemi
authors.forename: A
authors.initials: A
authors.lastname: Joukainen
authors.forename: P
authors.initials: P
authors.lastname: Penttilä
authors.forename: T
authors.initials: T
authors.lastname: Virén
authors.forename: S
authors.initials: S
authors.lastname: Saarakkala
authors.forename: H
authors.initials: H
authors.lastname: Kröger
authors.forename: J S
authors.initials: JS
authors.lastname: Jurvelin
authors.forename: J
authors.initials: J
authors.lastname: Töyräs
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001182:Arthroscopy / Q000379:methods*; D002102:Cadaver; D002358:Cartilage, Articular / Q000000981:diagnostic imaging*; D005240:Feasibility Studies; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging*; D006801:Humans; D066298:In Vitro Techniques; D007596:Joints / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D010008:Osteochondritis Dissecans / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014463:Ultrasonography / Q000379:methods*
keywords: Arthroscopy; Articular cartilage; High-frequency ultrasound; Knee; Osteoarthritis; Osteochondritis dissecans; Subchondral bone; Ultrasound imaging