The Inferior Stability Provided by the Glenohumeral Capsule Increases With External Rotation in the Abducted Glenohumeral Joint

2008 ◽  
Author(s):  
Nicholas J. Drury ◽  
Benjamin J. Ellis ◽  
Patrick J. McMahon ◽  
Jeffrey A. Weiss ◽  
Richard E. Debski
Keyword(s):  
Glenohumeral Joint ◽  
External Rotation ◽  
The Body ◽  
Multidirectional Instability ◽  
Glenohumeral Capsule ◽  
Anterior Direction

The shoulder is the most frequently dislocated major joint in the body, and the glenohumeral capsule is the primary stabilizer to the joint in positions of dislocation. Although the majority of dislocations occur in the anterior direction, multidirectional instability is common and usually occurs in the anterior and inferior directions. Clinicians have difficulty differentiating between multidirectional and unidirectional instability, and greater than 38% of post-operative recurrences may be due to misdiagnosis of the type of instability [1].

Injury to the Glenohumeral Capsule During Anterior Dislocation Results in Damage to the Anteroinferior Capsule

2011 ◽  
Author(s):  
Daniel P. Browe ◽  
Carrie A. Voycheck ◽  
Patrick J. McMahon ◽  
Richard E. Debski
Keyword(s):  
Surgical Repair ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Permanent Deformation ◽  
The Body ◽  
Anterior Dislocation ◽  
Recoverable Strain ◽  
Glenohumeral Capsule ◽  
Anterior Direction ◽  
Repair Techniques

The glenohumeral joint is the most frequently dislocated major joint in the body with about 2% of the population dislocating their shoulders between the ages of 18 and 70 [1]. About 80% of these shoulder dislocations occur in the anterior direction, and they most commonly occur in the apprehension position, which is characterized by 60° of glenohumeral abduction and 60° of external rotation [2]. The most common pathology associated with dislocation is instability due to permanent deformation [3]. Current surgical repair techniques for shoulder dislocations are inadequate with about 25% of patients still experiencing pain and instability after surgery [4]. By assessing the strain distribution, it is possible to determine the stabilizing function of the various capsular regions. In addition, surgeons could benefit from knowing the location and extent of tissue damage when placating the capsule during repair procedures. Therefore, the objective of this study was to determine the location and extent of injury to the anteroinferior capsule during anterior dislocation by quantifying the strain at dislocation and the non-recoverable strain following dislocation.

Effects of Gender on the Mechanical Properties of the Glenohumeral Capsule: Implications for Surgical Repair Techniques

2007 ◽  
Author(s):  
Eric J. Rainis ◽  
Carrie A. Voycheck ◽  
Elizabeth A. Timcho ◽  
Patrick J. McMahon ◽  
Richard E. Debski
Keyword(s):  
Mechanical Properties ◽  
Surgical Repair ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Joint Stiffness ◽  
The Body ◽  
Males And Females ◽  
Glenohumeral Capsule ◽  
Gender Specific ◽  
Repair Techniques

The glenohumeral joint is the most dislocated major joint in the body and the axillary pouch of the glenohumeral capsule is the primary stabilizer at the extreme ranges of external rotation. [1] Procedures to repair the capsule following dislocation result in 12–25% of patients still experiencing pain and instability. [2] Studies performing clinical exams have found inconsistent data on differences between males and females. Increased laxity in the glenohumeral joint of females has been found as well as overall hypermobility when compared to males. [3,4] However, others have found no differences in overall joint stiffness between genders. [5] These findings suggest that a difference in the mechanical properties might exist between genders. Therefore, the objective of this study was to determine the effects of gender on the mechanical properties of the axillary pouch during tensile loading. A combined experimental and computational approach was used to evaluate the properties of the tissue. This data could potentially be utilized to improve surgical procedures and necessitate gender-specific repair techniques.

Maximum Principal Strains in the Glenohumeral Capsule During a Clinical Exam: A Validated Finite Element Model

2007 ◽  
Author(s):  
Nicholas J. Drury ◽  
Benjamin J. Ellis ◽  
Susan M. Moore ◽  
Jeffrey A. Weiss ◽  
Richard E. Debski
Keyword(s):  
Strain Distribution ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Surgical Techniques ◽  
Element Model ◽  
The Body ◽  
External Loading ◽  
Glenohumeral Ligament ◽  
Glenohumeral Capsule ◽  
Principal Strains

The shoulder is the most frequently dislocated joint in the body, with 80% of dislocations occurring in the anterior direction [1]. One of the primary contributors to anterior shoulder stability is the glenohumeral capsule. Up to 23% of repaired shoulders redislocate following arthroscopic surgical techniques [2], and the function of the capsule in response to external loading remains unclear. Information on the strain distribution throughout the capsule during joint motion can help lead to more effective pre- and post-surgical diagnostics for capsular pathologies. One common diagnostic examination is the apprehension test, in which anterior loading is applied to the humerus at 60° of glenohumeral abduction with varying amounts of external rotation. The inferior glenohumeral ligament (IGHL), composed of three regions, the anterior band (AB-IGHL), axillary pouch, and posterior band (PB-IGHL), has been shown to be the primary region of the capsule to provide stability in this joint position [3]. The objective of this study was to determine the maximum principal strains in each region of the IGHL during an apprehension test at 0, 30, and 60° of external rotation, using a validated subject-specific model of the glenohumeral joint. The strain distribution may help elucidate the function of these regions in providing stability and transferring load between the humerus and scapula.

Development of a Finite Element Model of the Inferior Glenohumeral Ligament of the Glenohumeral Joint

2003 ◽  
Author(s):  
William J. Newman ◽  
Richard E. Debski ◽  
Susan M. Moore ◽  
Jeffrey A. Weiss
Keyword(s):  
Finite Element ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Element Model ◽  
Fe Modeling ◽  
Glenohumeral Ligament ◽  
Subject Specific ◽  
Inferior Glenohumeral Ligament ◽  
Glenohumeral Capsule ◽  
Shoulder Stability

The shoulder is one of the most complex and often injured joints in the human body. The inferior glenohumeral ligament (IGHL), composed of the anterior band (AB), posterior band (PB) and the axillary pouch, has been shown to be an important contributor to anterior shoulder stability (Turkel, 1981). Injuries to the IGHL of the glenohumeral capsule are especially difficult to diagnose and treat effectively. The objective of this research was to develop a methodology for subject-specific finite element (FE) modeling of the ligamentous structures of the glenohumeral joint, specifically the IGHL, and to determine how changes in material properties affect predicted strains in the IGHL at 60° of external rotation. Using the techniques developed in this research, an improved understanding of the contribution of the IGHL to shoulder stability can be acquired.

Mechanical Properties of the Glenohumeral Capsule Change With Simulated Injury

2010 ◽  
Author(s):  
Carrie A. Voycheck ◽  
Patrick J. McMahon ◽  
Richard E. Debski
Keyword(s):  
Glenohumeral Joint ◽  
Tissue Sample ◽  
Biomechanical Properties ◽  
Recurrent Instability ◽  
Glenohumeral Ligament ◽  
Inferior Glenohumeral Ligament ◽  
Normal Stability ◽  
Glenohumeral Capsule ◽  
Anterior Direction ◽  
Repair Techniques

The glenohumeral joint suffers more dislocations than any other joint, most of which occur in the anterior direction. The anterior band of the inferior glenohumeral ligament (AB-IGHL) is the primary restraint to these dislocations and as a result experiences the highest strains during these events. [1] Injuries to the capsule following dislocation include permanent tissue deformation that increases joint mobility and contributes to recurrent instability. [2] This deformation can be quantified by measuring nonrecoverable strain. [3] Simulated injury of the capsule results in permanently elongated tissue and nonrecoverable strain. Current surgical repair techniques are subjective and may not fully address all capsular tissue pathologies resulting from dislocation. Surgeons typically repair the injured capsule by plicating the stretched-out tissue; however, these techniques are inadequate with 23% of patients needing an additional repair. [4] Quantitative data on the changes in the biomechanical properties of the capsule following dislocation may help to predict the amount of capsular tissue to plicate for restoring normal stability. Therefore, the objectives of this study were to quantify changes in stiffness and material properties of the AB-IGHL tissue sample following simulated injury (creation of nonrecoverable strain).

Injury to the Glenohumeral Capsule During Anterior Dislocation Leads to Higher Joint Contact Forces During Simulated Clinical Exams

2011 ◽  
Author(s):  
Carrie A. Voycheck ◽  
Daniel P. Browe ◽  
Patrick J. McMahon ◽  
Richard E. Debski
Keyword(s):  
Glenohumeral Joint ◽  
External Rotation ◽  
Permanent Deformation ◽  
Supraspinatus Tendon ◽  
Contact Forces ◽  
Anterior Dislocation ◽  
Joint Stability ◽  
Articular Surfaces ◽  
Increased Risk ◽  
Glenohumeral Capsule

Glenohumeral joint stability is maintained by a combination of active and passive soft tissue structures and osteoarticular contact. Anatomical structures that contribute to each of these categories include the rotator cuff muscles, the glenohumeral capsule, and the contact between the articular surfaces of the humeral head and glenoid of the scapula, respectively. Dislocation may result in injury to one or more of these stabilizing components requiring the other structures to account for the deficit. For example, previous research has shown that a torn supraspinatus tendon results in increased bony contact forces during glenohumeral abduction. [1] Another common injury resulting from dislocation is permanent deformation of the glenohumeral capsule as the capsule is the primary static restraint to anterior translation in positions of external rotation. [2] Increased joint translations and rotations usually occur following permanent deformation [3] indicating a loss in joint stability provided by the capsule. These changes in joint kinematics following dislocation imply that differences in the contact forces between the humerus and scapula may exist as well. Irregular contact between two articular surfaces can lead to abnormal wear and an increased risk of osteoarthritis when left untreated. Therefore, the objective of this work was to assess the affect of anterior dislocation on glenohumeral joint stability by determining the in situ force in the glenohumeral capsule and the bony contact forces between the humerus and scapula during a simulated clinical exam at three joint positions in the intact and injured joint.

scholarly journals Direction of Capsular Strain Implies Surgical Repair Following Recurrent Anterior Shoulder Dislocation

2018 ◽  
Vol 6 (7_suppl4) ◽  
pp. 2325967118S0011
Author(s):  
Tetsuya Takenaga ◽  
Masahito Yoshida ◽  
Calvin Chan ◽  
Volker Musahl ◽  
Albert Lin ◽  
...  
Keyword(s):  
Glenohumeral Joint ◽  
External Rotation ◽  
Reference State ◽  
Circular Statistics ◽  
Recoverable Strain ◽  
Glenohumeral Ligament ◽  
The Maximum Principle ◽  
Capsular Plication ◽  
Glenohumeral Capsule ◽  
Williams Test

Objectives: Capsular plication is often performed in addition to arthroscopic Bankart repair. However, little is known regarding the direction of capsular injury making the direction of plication fairly arbitrary. This study aimed to determine the optimal direction for capsular plication within four sub-regions of the inferior glenohumeral capsule following multiple dislocations. Methods: Seven fresh-frozen cadaveric shoulders (age range 48-66 yrs) were dissected free of all soft tissue except the glenohumeral capsule. A grid of strain markers was affixed to the anterior and posterior band (A/PB) of the inferior glenohumeral ligament (IGHL), and the axillary pouch. The position of the markers while the capsule was inflated with minimal pressure served as the reference state. The humerus and scapula were then mounted in a 6 degree-of-freedom robotic testing system. At 60 degrees of abduction and 60 degrees of external rotation of the glenohumeral joint, an anterior load was applied to reach an anterior translation of one half the maximum AP width of the glenoid plus 10 mm. This definition of dislocation resulted in non-recoverable strain and a reproducible Bankart lesion. Following 1, 2, 3, 4, 5 and 10 dislocations, the positions of the strain markers were again recorded with the capsule inflated. The difference in these positions compared to the reference state defined the non-recoverable strain. The strain map was split into four sub-regions, the anterior band of IGHL (AB), anterior axillary pouch (AA), posterior axillary pouch (PA), and the posterior band of IGHL (PB) (Fig. 1). The angle of deviation between each of the maximum principle strain vectors and the AB-IGHL or PB-IGHL for the anterior and posterior regions of the capsule were determined using ImageJ. Circular statistics were employed to calculate mean direction of each sub-region and a Watson-Williams test was performed to compare mean direction among each dislocation with significance set at p < 0.05. The mean direction of all strain vectors in each sub-region was categorized as parallel or perpendicular to the AB-IGHL or PB-IGHL serving as the clinical reference. Direction ranging from 0 to 45 or 135 to 180 degrees was categorized as parallel. Direction ranging between 45 and 135 degrees was categorized as perpendicular. Results: The direction of 81.8% of the AB sub-regions was categorized as parallel and 18.2% categorized as perpendicular to the AB-IGHL. Direction of 61.3% of the AA sub-region was categorized as parallel (Table 1) and 38.7% categorized as perpendicular to AB-IGHL. The direction of 33.3% of the PA sub-region was categorized as parallel and 66.7% categorized as perpendicular to the PB-IGHL. The direction of 21.4% of PB sub-region was categorized as parallel and 78.6% categorized as perpendicular to PB-IGHL. A Watson-Williams test demonstrated that the direction of 81.3% of the sub-regions were not significantly different (p > 0.05) among dislocations for each specimen (Table 1). Conclusion: The non-recoverable strain in most of the AB and AP sub-regions were categorized as parallel to the AB-IGHL while for the PA and PB sub-regions mostly perpendicular to the PB-IGHL. These findings imply that it may be more optimal to plicate the anteroinferior capsule parallel to the AB-IGHL while posteroinferior capsular plication, which is often not classically considered for plication in the setting of anterior instability, may also be necessary and best performed perpendicular to the PB-IGHL. [Figure: see text][Table: see text]

Ligamentous Restraints to External Rotation of the Humerus in the Late-Cocking Phase of Throwing

2000 ◽  
Vol 28 (2) ◽  
pp. 200-205 ◽  
Author(s):  
John E. Kuhn ◽  
Michael J. Bey ◽  
Laura J. Huston ◽  
Ralph B. Blasier ◽  
Louis J. Soslowsky
Keyword(s):  
Rotator Cuff ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Coracoacromial Ligament ◽  
Glenohumeral Ligament ◽  
Coracohumeral Ligament ◽  
Potential Source ◽  
Glenohumeral Ligaments ◽  
Inferior Glenohumeral Ligament ◽  
Glenohumeral Capsule

The late-cocking phase of throwing is characterized by extreme external rotation of the abducted arm; repeated stress in this position is a potential source of glenohumeral joint laxity. To determine the ligamentous restraints for external rotation in this position, 20 cadaver shoulders (mean age, 65 16 years) were dissected, leaving the rotator cuff tendons, coracoacromial ligament, glenohumeral capsule and ligaments, and coracohumeral ligament intact. The combined superior and middle glenohumeral ligaments, anterior band of the inferior glenohumeral ligament, and the entire inferior glenohumeral ligament were marked with sutures during arthroscopy. Specimens were mounted in a testing apparatus to simulate the late-cocking position. Forces of 22 N were applied to each of the rotator cuff tendons. An external rotation torque (0.06 N m/sec to a peak of 3.4 N m) was applied to the humerus of each specimen with the capsule intact and again after a single randomly chosen ligament was cut (N 5 in each group). Cutting the entire inferior glenohumeral ligament resulted in the greatest increase in external rotation (10.2° 4.9°). This was not significantly different from sectioning the coracohumeral ligament (8.6° 7.3°). The anterior band of the inferior glenohumeral ligament (2.7° 1.5°) and the superior and middle glenohumeral ligaments (0.7° 0.3°) were significantly less important in limiting external rotation.

The Impact of Glenoid Labrum Thickness and Modulus on Labrum and Glenohumeral Capsule Function

2010 ◽  
Vol 132 (12) ◽  
Author(s):  
Nicholas J. Drury ◽  
Benjamin J. Ellis ◽  
Jeffrey A. Weiss ◽  
Patrick J. McMahon ◽  
Richard E. Debski
Keyword(s):  
Finite Element ◽  
Glenohumeral Joint ◽  
External Rotation ◽  
Tensile Modulus ◽  
Activity Levels ◽  
Average Strain ◽  
Glenoid Labrum ◽  
Age Related ◽  
Glenohumeral Capsule ◽  
The Impact

The glenoid labrum is an integral component of the glenohumeral capsule’s insertion into the glenoid, and changes in labrum geometry and mechanical properties may lead to the development of glenohumeral joint pathology. The objective of this research was to determine the effect that changes in labrum thickness and modulus have on strains in the labrum and glenohumeral capsule during a simulated physical examination for anterior instability. A labrum was incorporated into a validated, subject-specific finite element model of the glenohumeral joint, and experimental kinematics were applied simulating application of an anterior load at 0 deg, 30 deg, and 60 deg of external rotation and 60 deg of glenohumeral abduction. The radial thickness of the labrum was varied to simulate thinning tissue, and the tensile modulus of the labrum was varied to simulate degenerating tissue. At 60 deg of external rotation, a thinning labrum increased the average and peak strains in the labrum, particularly in the labrum regions of the axillary pouch (increased 10.5% average strain) and anterior band (increased 7.5% average strain). These results suggest a cause-and-effect relationship between age-related decreases in labrum thickness and increases in labrum pathology. A degenerating labrum also increased the average and peak strains in the labrum, particularly in the labrum regions of the axillary pouch (increased 15.5% strain) and anterior band (increased 10.4% strain). This supports the concept that age-related labrum pathology may result from tissue degeneration. This work suggests that a shift in capsule reparative techniques may be needed in order to include the labrum, especially as activity levels in the aging population continue to increase. In the future validated, finite element models of the glenohumeral joint can be used to explore the efficacy of new repair techniques for glenoid labrum pathology.

The Effect of Anterior Dislocation on the Mechanical Properties of the Inferior Glenohumeral Ligament

2012 ◽  
Author(s):  
Daniel P. Browe ◽  
Carrie A. Rainis ◽  
Patrick J. McMahon ◽  
Richard E. Debski
Keyword(s):  
Mechanical Properties ◽  
Glenohumeral Joint ◽  
Permanent Deformation ◽  
Recurrent Dislocation ◽  
The Body ◽  
Anterior Dislocation ◽  
Glenohumeral Ligament ◽  
Inferior Glenohumeral Ligament ◽  
Glenohumeral Capsule ◽  
Repair Techniques

The glenohumeral joint is the most frequently dislocated major joint in the body with about 2% of the population dislocating their shoulders between the ages of 18 and 70 [1]. Instability due to permanent deformation of the glenohumeral capsule is commonly associated with dislocation [2]. Current surgical repair techniques for shoulder dislocations typically consist of plication of the glenohumeral capsule, or folding the tissue over on itself, to reduce redundancy in the capsule and restore stability to the shoulder. Up to 25% of patients who undergo surgery for a shoulder dislocation still experience pain, instability, and recurrent dislocation after surgery [3]. It is hypothesized that the mechanical properties of the glenohumeral capsule change in response to dislocation. In addition, the magnitude and location of these changes may have implications for the ideal location and extent of plication. Therefore, the objective of this study was to quantify the mechanical properties of the axillary pouch of the glenohumeral capsule in tension and shear after anterior dislocation.

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