title: Estimation of dynamic, in vivo soft-tissue deformation: experimental technique and application in a canine model of tendon injury and repair.
abstract: Outcomes after rotator cuff surgery are typically assessed with measures of strength, joint motion, or pain, but these measures do not provide a direct assessment of tissue function as healing progresses. To address this limitation, this manuscript describes biplane X-ray analysis as a technique for quantifying in vivo soft-tissue deformation. Tantalum beads were implanted in the humerus and infraspinatus tendon in a canine model of tendon injury and repair. Biplane X-ray images were acquired during treadmill trotting and tissue deformation was estimated from the three-dimensional bead positions. Changes over time were characterized by the mean, range, and normalized range (i.e., range/mean) of interbead distance. Intact tendon repair tissue demonstrated significant decreases over time in the mean (p = 0.003), range (p = 0.001), and normalized range (p = 0.001) of interbead distance. Failed tendon repair tissue demonstrated significant decreases over time in the range (p =  0.05) and normalized range (p = 0.04) of interbead distance. In an uninjured control, differences over time in the interbead distance parameters were not detected. This approach is a promising technique for estimating changes over time in soft-tissue deformation. These preliminary data indicate appreciable differences between normal tendons, intact repairs, and failed repairs.
authors.affiliation: Henry Ford Hospital, Detroit, MI, USA. bey@bjc.hfh.edu
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Bey
authors.forename: Stephanie K
authors.initials: SK
authors.lastname: Kline
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Baker
authors.forename: Jesse A
authors.initials: JA
authors.lastname: McCarron
authors.forename: Joseph P
authors.initials: JP
authors.lastname: Iannotti
authors.forename: Kathleen A
authors.initials: KA
authors.lastname: Derwin
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004285:Dogs; D006811:Humerus / Q000000981:diagnostic imaging; D023421:Models, Animal; D011859:Radiography; D020127:Recovery of Function; D000070636:Rotator Cuff Injuries; D013635:Tantalum; D013708:Tendon Injuries / Q000000981:diagnostic imaging* / Q000503:physiopathology; D013710:Tendons / Q000000981:diagnostic imaging; D014945:Wound Healing
chemical_list: D013635:Tantalum