title: Proximal biceps tendon--a biomechanical analysis of the stability at the bicipital groove.
abstract: The subscapularis tendon, coracohumeral ligament, and transverse humeral ligament are all believed to contribute to biceps tendon stability within the bicipital groove. In order to examine the relative contribution of these soft tissue structures to proximal biceps tendon stability, 11 fresh frozen cadaveric shoulder specimens were prepared and mounted onto a custom jig. A three-dimensional digitizer was utilized to record biceps tendon excursion in various shoulder positions. In sequential order, these structures were then sectioned, and biceps tendon excursion was again recorded. We found that sectioning of the subscapularis tendon significantly increased biceps tendon excursion, compared to intact specimens (8.1 +/- 4.1 mm vs. 4.3 +/- 3.6 mm; p < 0.006). In contrast, isolated sectioning of the transverse humeral ligament or the coracohumeral ligament did not significantly increase biceps excursion (5.4 +/- 2.5 mm, p = 0.26; 5.6 +/- 1.3 mm, p = 0.24). When two structures were sectioned, significant excursion in the biceps tendon only occurred in specimens where the subscapularis tendon was one of the sectioned structures. The preliminary data suggest that, of the three tested soft tissue structures, the subscapularis tendon is the most important stabilizer of the proximal biceps and that clinically significant lesions of the proximal biceps tendon may be associated with a defect in the subscapularis tendon.
authors.affiliation: Department of Orthopaedic Surgery, NYU Hospital for Joint Diseases, 301 E. 17th Street, New York, New York 10003, USA. young.kwon@nyumc.org
authors.forename: Young W
authors.initials: YW
authors.lastname: Kwon
authors.forename: Jason
authors.initials: J
authors.lastname: Hurd
authors.forename: Keith
authors.initials: K
authors.lastname: Yeager
authors.forename: Charbel
authors.initials: C
authors.lastname: Ishak
authors.forename: Peter S
authors.initials: PS
authors.lastname: Walker
authors.forename: Sami
authors.initials: S
authors.lastname: Khan
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Bosco
authors.forename: Laith M
authors.initials: LM
authors.lastname: Jazrawi
mesh_terms: D001696:Biomechanical Phenomena; D002102:Cadaver; D003198:Computer Simulation; D006801:Humans; D007593:Joint Instability / Q000473:pathology / Q000503:physiopathology*; D008023:Ligaments, Articular / Q000473:pathology / Q000503:physiopathology*; D008875:Middle Aged; D008953:Models, Anatomic; D016059:Range of Motion, Articular; D012785:Shoulder Joint / Q000473:pathology / Q000503:physiopathology*; D013708:Tendon Injuries / Q000473:pathology / Q000503:physiopathology; D013710:Tendons / Q000473:pathology / Q000503:physiopathology*