Material Properties of the Axillary Pouch of the Glenohumeral Capsule: Is Isotropic Material Symmetry Appropriate?

Rainis, Eric J.; Maas, Steve A.; Henninger, Heath B.; McMahon, Patrick J.; Weiss, Jeffrey A.; Debski, Richard E.

doi:10.1115/1.3005169

Cited by 15 publications

(24 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A combined experimental–computational approach was utilized to determine the material coefficients for the glenohumeral capsule based on an isotropic constitutive model 12,16,32,37. Tissue samples were excised from each capsular region shown in Fig.…”

Section: Methodsmentioning

confidence: 99%

“…The length, width, and thickness of the tissue sample were prescribed and the experimentally recorded elongation was used to drive the simulations. An inverse finite element optimization routine determined the material coefficients for an isotropic hypoelastic constitutive model that has been used previously to model the glenohumeral capsule 16,37,39,45. Since two sets of coefficients were determined for the axillary pouch and posterior regions, the average of the material coefficients served as input to the finite element models (Table 1).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

The Glenohumeral Capsule Should be Evaluated as a Sheet of Fibrous Tissue: A Validated Finite Element Model

et al. 2009

Self Cite

View full text Add to dashboard Cite

The function of the glenohumeral capsule has typically been evaluated by isolating several discrete, ligamentous regions during experimental and computational investigations. However, recent data suggests that the regions of the glenohumeral capsule have significant interactions and function multiaxially. Therefore, examining the function of the inferior glenohumeral ligament as a discrete structure may not be appropriate. The objective of this work was to validate the predicted strain distribution and deformed shape of the inferior glenohumeral ligament using experimental data for two subject-specific finite element models: (1) a continuous model including all capsular regions, and (2) a discrete model including only the inferior glenohumeral ligament. The distribution of maximum principal strain and deformed shape of the glenohumeral capsule was determined for a cadaveric shoulder in a joint position frequently associated with dislocation (60° of glenohumeral abduction, 52° of external rotation, and a 25 N anterior load applied to the humerus). The experimental kinematics were then applied to the two finite element models constructed from the geometry and material properties from the same cadaveric shoulder and the predicted strain distributions and deformed shapes were determined. For the continuous model, the average difference between predicted strains and experimental strains was less than 5%. The predicted deformed shape was also similar to experimental data, with the anterior band of the inferior glenohumeral ligament clearly wrapped around the humeral head. In contrast, large differences existed between the strains predicted by the discrete model when compared to the experimental strains for this joint position (average difference from experimental data was 20%). In addition, the predicted deformed shape of the inferior glenohumeral ligament did not wrap around the humeral head. These differences may be attributed to neglecting the complex interactions between the anterior band of the inferior glenohumeral ligament with the neighboring capsular regions. Thus, the glenohumeral capsule should not be evaluated as several discrete structures. Rather, it should be evaluated as a single sheet of fibrous tissue.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

The Glenohumeral Capsule Should be Evaluated as a Sheet of Fibrous Tissue: A Validated Finite Element Model

et al. 2009

Self Cite

View full text Add to dashboard Cite

show abstract

“…28 Following recovery, the capsule was positioned in the reference strain configuration and re-inflated to 0.75 psi. The positions of the strain markers were recorded and served as the non-recoverable strain state.…”

Section: Methodsmentioning

confidence: 99%

Capsule function following anterior dislocation: Implications for diagnosis of shoulder instability

Rainis

Browe

McMahon

et al. 2013

Journal Orthopaedic Research

Self Cite

View full text Add to dashboard Cite

During shoulder dislocation, the glenohumeral capsule undergoes non-recoverable strain, leading to joint instability. Clinicians use physical exams to diagnose injury and direct repair procedures; however, they are subjective and do not provide quantitative information. Our objectives were to: (1) determine the relationship between capsule function following anterior dislocation and non-recoverable strain; and (2) identify joint positions at which physical exams can be used to detect non-recoverable strain in specific capsule regions. Physical exams were simulated at three joint positions including external rotation (ER) using robotic technology before and after anterior dislocation. The resulting joint kinematics, strain distribution in the capsule, and non-recoverable strain were determined. Following dislocation, anterior translation increased by as much as 48% (08 ER: p ¼ 0.03; 308 ER: p ¼ 0.03; 608 ER: p < 0.01). Capsule sub-regions with less non-recoverable strain required more ER to detect differences in the strain ratios between the intact and injured joint. Strain ratio changes on the humeral side of the posterior axillary pouch (0.31 AE 0.32) were significant at all joint positions (08 ER: p ¼ 0.03; 308 ER: p ¼ 0.048; 608 ER: p ¼ 0.04), whereas strain ratio differences on the humeral side of the anterior axillary pouch (0.18 AE 0.21) were significant only at 608 of ER (p ¼ 0.03). Therefore, standardizing physical exams for joint position could help surgeons identify specific locations of non-recoverable strain that may have been ignored. ß

show abstract

“…A recent experimental study on the subfailure mechanical properties of the glenohumeral axillary pouch found its biaxial properties were not significantly different. 20 The current study suggests that isotropy may be found in failure properties as well.…”

Section: Discussionmentioning

confidence: 86%

“…25 Failure criteria for ligamentous materials are not sufficiently developed at this time to predict the role of the minimum principal strain on failure. 4,9,10,28 While glenohumeral capsule is membranous in nature, few studies to date have tested its biaxial mechanical properties, 15,20 likely because such testing is difficult. Numerous studies have excised thickened portions of the capsule such as the IGHL in BoneLigament-Bone specimens (BLB) and then subjected them to uniaxial tests.…”

Section: Introductionmentioning

confidence: 99%

Relationships Between Total and Non-Recoverable Strain Fields in Glenohumeral Capsule During Shoulder Subluxation

Malicky

Soslowsky

2009

Ann Biomed Eng

View full text Add to dashboard Cite

Non-recoverable strain in the glenohumeral capsule is of prime clinical significance, but the factors that contribute to non-recoverable strain are largely unknown. This study examined the relationship between total and non-recoverable strain in the antero-inferior glenohumeral capsule using an experimental model. Maximum principal total strain alone explained up to 35% of the variance in non-recoverable strain. A multiple regression model, including variables for lateral position and specimen, explained 50% of the variance in non-recoverable strain. Both linear and quadratic terms for maximum principal total strain were significant predictors of non-recoverable strain. The correlation of total and non-recoverable strain directions exhibited a slope of nearly 1:1. The regression model showed that non-recoverable strain is likely to be low for small levels of total strain, and increase non-linearly with total strain. Non-recoverable strain tended to be higher closer to the glenoid, even when controlling for total strain. Minimum principal total strain was not a significant predictor of non-recoverable strain for the cases examined, indicating that the glenohumeral capsule may demonstrate uniaxial failure behavior even when loaded biaxially. These results are important toward prediction of non-recoverable strain in computational models of glenohumeral subluxation, as well as for theoretical models of ligament failure.

show abstract

Material Properties of the Axillary Pouch of the Glenohumeral Capsule: Is Isotropic Material Symmetry Appropriate?

Cited by 15 publications

References 28 publications

The Glenohumeral Capsule Should be Evaluated as a Sheet of Fibrous Tissue: A Validated Finite Element Model

The Glenohumeral Capsule Should be Evaluated as a Sheet of Fibrous Tissue: A Validated Finite Element Model

Capsule function following anterior dislocation: Implications for diagnosis of shoulder instability

Relationships Between Total and Non-Recoverable Strain Fields in Glenohumeral Capsule During Shoulder Subluxation

Contact Info

Product

Resources

About