title: Effects of region and sex on the mechanical properties of the glenohumeral capsule during uniaxial extension.
abstract: Surgical repair of the glenohumeral capsule after dislocation ignores regional boundaries of the capsule and is not sex specific. However, each region of the capsule functions to stabilize the joint in different positions, and differences in joint laxity between men and women have been found. The objectives of this research were to determine the effects of region (axillary pouch and posterior capsule) and sex on the material properties of the glenohumeral capsule. Boundary conditions derived from experiments were used to create finite-element models that applied tensile deformations to tissue samples from the capsule. The material coefficients of a hyperelastic constitutive model were determined via inverse finite-element optimization, which minimized the difference between the experimental and finite-element model-predicted load-elongation curve. These coefficients were then used to create stress-stretch curves representing the material properties of the capsule regions for each sex in response to uniaxial extension. For the axillary pouch, the C1 (men: 0.28+/-0.39 MPa and women: 0.23+/-0.12 MPa) and C2 (men: 8.2+/-4.1 and women: 7.7+/-3.0) material coefficients differed between men and women by only 0.05 MPa and 0.5, respectively. Similarly, the posterior capsule coefficients differed by 0.15 MPa (male: 0.49+/-0.26 MPa and female: 0.34+/-0.20 MPa) and 0.6 (male: 7.8+/-2.9 and female: 7.2+/-3.0), respectively. No differences could be detected in the material coefficients between regions or sexes. As a result, surgeons may not need to consider region- and sex-specific surgical repair techniques. Furthermore, finite-element models of the glenohumeral joint may not need region- or sex-specific material coefficients when using this constitutive model.
authors.affiliation: Musculoskeletal Research Center, Department of Bioengineering, Swanson School of Engineering, University of Pittsburgh, 405 Center for Bioengineering, 300 Technology Dr., Pittsburgh, PA 15219, USA.
authors.forename: Carrie A
authors.initials: CA
authors.lastname: Voycheck
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Rainis
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: McMahon
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Weiss
authors.forename: Richard E
authors.initials: RE
authors.lastname: Debski
mesh_terms: D003198:Computer Simulation; D055119:Elastic Modulus / Q000502:physiology; D005260:Female; D006801:Humans; D017746:Joint Capsule / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D016059:Range of Motion, Articular / Q000502:physiology; D012737:Sex Factors; D012785:Shoulder Joint / Q000502:physiology*; D013314:Stress, Mechanical; D013718:Tensile Strength / Q000502:physiology
references.citation: Arthroscopy. 2006 Oct;22(10):1126-31
references.pmid: 17027412
references.citation: Am J Sports Med. 2002 Jan-Feb;30(1):136-51
references.pmid: 11799012
references.citation: J Biomech. 2002 Jul;35(7):943-50
references.pmid: 12052396
references.citation: J Bone Joint Surg Am. 1996 Nov;78(11):1677-84
references.pmid: 8934481
references.citation: Acta Orthop Scand. 1985 Apr;56(2):149-51
references.pmid: 4013704
references.citation: J Biomech Eng. 1998 Dec;120(6):757-63
references.pmid: 10412460
references.citation: J Biomech. 2005 Jun;38(6):1365-9
references.pmid: 15863121
references.citation: Clin Orthop Relat Res. 1983 Mar;(173):20-6
references.pmid: 6825333
references.citation: Eur J Appl Physiol. 2003 Feb;88(6):520-6
references.pmid: 12560950
references.citation: J Bone Joint Surg Am. 2000 Jul;82-A(7):991-1003
references.pmid: 10901314
references.citation: Am J Sports Med. 1996 Jul-Aug;24(4):468-71
references.pmid: 8827305
references.citation: Ann Biomed Eng. 2010 Jan;38(1):66-76
references.pmid: 19911278
references.citation: J Bone Joint Surg Am. 1983 Mar;65(3):343-9
references.pmid: 6826597
references.citation: J Shoulder Elbow Surg. 2005 Jan-Feb;14(1 Suppl S):24S-31S
references.pmid: 15726084
references.citation: J Biomech. 2007;40(3):603-12
references.pmid: 16580002
references.citation: J Shoulder Elbow Surg. 2005 Mar-Apr;14(2):201-6
references.pmid: 15789015
references.citation: J Biomech. 1998 Aug;31(8):753-7
references.pmid: 9796676
references.citation: Am J Sports Med. 1997 Sep-Oct;25(5):609-13
references.pmid: 9302464
references.citation: Am J Sports Med. 2004 Jul-Aug;32(5):1324-30
references.pmid: 15262661
references.citation: Clin Biomech (Bristol, Avon). 1999 Aug;14(7):471-6
references.pmid: 10521630
references.citation: J Biomech. 1970 Jan;3(1):111-24
references.pmid: 5521524
references.citation: J Shoulder Elbow Surg. 2005 Jan-Feb;14(1 Suppl S):49S-57S
references.pmid: 15726087
references.citation: J Biomech Eng. 2001 Apr;123(2):170-5
references.pmid: 11340878
references.citation: Clin Orthop Relat Res. 2000 Mar;(372):110-22
references.pmid: 10738420
references.citation: J Shoulder Elbow Surg. 2001 Jan-Feb;10(1):28-36
references.pmid: 11182733
references.citation: Tohoku J Exp Med. 1993 Nov;171(3):203-10
references.pmid: 8160176
references.citation: J Am Acad Orthop Surg. 2009 Mar;17(3):125-36
references.pmid: 19264706
references.citation: J Biomech. 2006;39(16):2943-50
references.pmid: 16387307
references.citation: J Bone Joint Surg Am. 1984 Feb;66(2):159-68
references.pmid: 6693441
references.citation: Clin Biomech (Bristol, Avon). 2006 Dec;21(10):1060-6
references.pmid: 16949187
references.citation: Am J Sports Med. 1994 Sep-Oct;22(5):578-84
references.pmid: 7810778
references.citation: Arthroscopy. 1997 Aug;13(4):418-25
references.pmid: 9276046
references.citation: J Shoulder Elbow Surg. 2003 May-Jun;12(3):247-52
references.pmid: 12851577
references.citation: J Shoulder Elbow Surg. 1996 Jul-Aug;5(4):269-79
references.pmid: 8872924
references.citation: Med Sci Sports Exerc. 2000 Oct;32(10):1685-90
references.pmid: 11039638
references.citation: Am J Sports Med. 1994 May-Jun;22(3):352-8
references.pmid: 8037276
references.citation: J Shoulder Elbow Surg. 1999 Jul-Aug;8(4):345-50
references.pmid: 10472008
references.citation: J Orthop Res. 1992 Mar;10(2):187-97
references.pmid: 1740736
references.citation: J Orthop Res. 2003 Nov;21(6):1098-106
references.pmid: 14554224
references.citation: J Athl Train. 2002 Sep;37(3):240-245
references.pmid: 12937579
references.citation: J Biomech Eng. 2004 Apr;126(2):284-8
references.pmid: 15179860
references.citation: J Shoulder Elbow Surg. 1998 Sep-Oct;7(5):467-71
references.pmid: 9814924
references.citation: J Biomech Eng. 1990 Feb;112(1):38-45
references.pmid: 2308302
references.citation: J Biomech Eng. 2009 Mar;131(3):031007
references.pmid: 19154066
references.citation: Clin Orthop Relat Res. 2001 Jun;(387):165-70
references.pmid: 11400878