Middle Glenohumeral Ligament Research Articles

Anterior labroligamentous structures of the glenohumeral joint: correlation of MR arthrography and anatomic dissection in cadavers.

The purpose of this study was to establish the accuracy of MR arthrography in depicting the morphology of the glenohumeral ligaments and the superior portion of the glenoid labrum. Findings on MR arthrography and those derived from careful dissection of gross specimens were compared in 15 cadaver shoulders, focusing on the morphology and size of the superior and middle glenohumeral ligaments and the morphology of the inferior glenohumeral ligament. The frequencies of sublabral recess and sublabral foramen seen on MR arthrography and at anatomic dissection were also compared. For the superior and middle glenohumeral ligaments, moderate correlation of size was found between measurements made on MR arthrograms and at anatomic dissection, with the Spearman's rank correlation coefficient calculated as .69990 and .71133, respectively. Morphologic descriptions of the inferior glenohumeral ligament based on MR arthrography and on anatomic dissection also showed good association (Cohen's kappa = .8936). Dissection revealed that the sublabral recess was present in 11 specimens. Of these, 10 recesses were identified on MR arthrograms. MR arthrography also revealed a sublabral recess that was not found at dissection. Four sublabral foramina were identified by both MR arthrography and dissection, and two were revealed only by MR arthrography. MR arthrography is useful in the evaluation of the glenohumeral ligaments and the superior portion of the labrum. Anatomic variations of these anterior intraarticular structures can be accurately shown by MR arthrography. In addition, estimation of the size of glenohumeral ligaments can be achieved with acceptable accuracy on MR arthrograms.

Glenohumeral joint: comparison of shoulder positions at MR arthrography.

To compare neutral, external rotation, and abduction external rotation positions of the glenohumeral joint during magnetic resonance (MR) arthrography in the assessment of the joint capsule, biceps-labral complex, and glenohumeral ligaments. MR imaging with intraarticular administration of gadopentetate dimeglumine was performed in 10 adult cadaveric glenohumeral joints. Fat-suppressed oblique coronal, oblique sagittal, and axial. T1-weighted spin-echo imaging and axial three-dimensional spoiled gradient-recalled imaging were performed with each shoulder in the neutral, external rotation, and abduction external rotation positions. Shoulders were sectioned in the planes that yielded optimal MR images. Anatomic and MR imaging findings were correlated. The biceps-labral complex was best visualized on oblique coronal and axial images obtained in external rotation. Oblique axial abduction external rotation imaging best delineated the inferior glenohumeral ligament but did not improve assessment of the superior and middle glenohumeral ligaments in comparison with findings in neutral and external rotation. Although MR arthrography of the glenohumeral joint clearly delineates the biceps-labral complex and glenohumeral ligaments, external rotation of the shoulder optimizes visualization of the former structures. Abduction external rotation is the best position for evaluation of the inferior glenohumeral ligament and anterior capsular attachment.

The anatomy of the glenohumeral ligamentous complex and its contribution to anterior shoulder stability

One hundred four enbalmed cadaver shoulders were evaluated. With a dorsal approach we opened the dorsal capsule after resecting the infraspinatus and teres minor muscles. For reaching the anterior capsule and the glenohumeral ligaments, the humeral head was resected. In this way we could quantify and qualify the glenohumeral ligaments and classfy the synovial recesses based on the classification system of DePalma into type I to VI. Secondary signs of shoulder instability were documented. The superior glenohumeral ligament was missing in 6 (5.8%) shoulders, the middle glenohumeral ligament in 16 (15.4%) shoulders, and the inferior glenohumeral ligament in 7 (6.8%) shoulders. Most of the synovial recesses belonged to group I (38.5%) and III (46.2%). As a secondary sign of instability four shoulders had a Hill-Sachs fracture and a bony Bankart lesion. All four shoulders had no middle glenohumeral ligament and a large anterior type IV recess.

Anterosuperior instability and the rotator interval

An improved understanding of the anatomy of the anterosuperior quadrant of the shoulder and the contributions that these structures make to shoulder stability along with the advances in shoulder arthroscopy have allowed for the recognition and delineation of a number of pathologic conditions. Traumatic avulsion of the superior and/or the middle glenohumeral ligaments can and do occur in the clinical setting, and these capsulolabral disruptions respond very effectively to arthroscopic reconstruction when nonsurgical measures have failed. Another important structure found in the anterosuperior quadrant of the shoulder includes the rotator interval capsule, which has been shown to contribute significantly to stability of the shoulder in both mechanical and clinical studies. Arthroscopic plication of the rotator interval capsule is effective in stabilizing selected cases of shoulder instability and in supplementing other arthroscopic stabilization procedures. This article describes the clinical and arthroscopic findings found with anterosuperior quadrant pathology and provides insights into differentiating pathology from normal variant anatomy. Surgical techniques involved in superior and middle glenohumeral ligament reconstruction as well as arthroscopic rotator interval plication are also described in detail.

MR ARTHROGRAPHY OF THE GLENOHUMERAL JOINT

This article explores MR arthrography of the glenohumeral joint, including normal anatomy of the glenoid labrum, glenohumeral ligaments, and biceps labral complex. Examples of glenohumeral joint instability include the Bankart lesion, anterior labroligamentous periosteal sleeve avulsion, glenolabral articular disruption, humeral avulsion of the glenohumeral ligament, and Bennet lesion. Normal variations include the sublabral foramen, the Buford complex, and cord-like middle glenohumeral ligament. Labral tears and paralabral cysts are also discussed.

The Buford complex--a variation of normal shoulder anatomy: MR arthrographic imaging features.

The purpose of this study was to show the MR arthrographic imaging features of a normal anatomic variation of the shoulder: the absence of the anterior superior labrum and the presence of a "cordlike" middle glenohumeral ligament,which together are known as the Buford complex. We retrospectively analyzed the MR arthrographic examinations of 10 patients with arthroscopically proven Buford complexes. MR arthrographic examinations showed an absent anterior superior labrum and an associated cordlike middle glenohumeral ligament in all patients. No contiguous tear of the superior labrum or anterior inferior labrum was evident. Originally, this variation was mistakenly diagnosed as a labral avulsion in two of the 10 patients. Also, a differential diagnosis of a superior labral tear was mistakenly offered for four patients. An absent anterior superior labrum and an associated cordlike middle glenohumeral ligament represent the normal variation that is known as the Buford complex rather than an avulsed labrum. This normal variation may be mistaken for a detached labrum.

Arthroscopically treated tears of the glenoid labrum. Factors influencing outcome.

Labral tears and associated glenohumeral ligament injuries were classified and treated arthroscopically in 83 patients. Transverse labral tears were the most common. Subtle increased glenohumeral translation was noted in 24% of patients. Glenohumeral ligament injury was present in 58% of the shoulders, with the middle and superior ligaments or middle ligaments alone most commonly involved. These ligament injuries were classified into different groups based on severity. Partial excision of the torn labrum was the primary treatment in all patients and was combined with glenohumeral ligament repair in 9 patients. Seventy-eight patients were available for subjective follow-up evaluation (average, 3.2 years), while 53 patients were objectively evaluated (average followup, 2.8 years). There were 14% excellent, 71% satisfactory, and 15% poor results. The main factor associated with poor results was a grade III glenohumeral ligament injury in which only partial excision of the torn labrum was performed. There was a positive correlation between injury to both the superior and middle glenohumeral ligaments and increased anterior translation demonstrated by preoperative stability testing at 60 degrees of humeral abduction in neutral rotation. We believe glenohumeral ligament injury is often associated with labral tears and arthroscopic partial labral excision is only effective in those patients who have grade I or II (less severe) glenohumeral ligament injuries.

The buford complex—The “cord-like” middle glenohumeral ligament and absent anterosuperior labrum complex: A normal anatomic capsulolabral variant

Two hundred consecutive shoulder arthroscopy videotapes were retrospectively reviewed, paying specific attention to the anatomy of the anterosuperior glenoid quadrant and especially the labroligamentous complex. Normal glenohumeral anatomy and all variations were carefully evaluated and recorded. Twenty-four (12%) patients had a sublabral foramen below the anterosuperior labrum; a "cord-like" middle glenohumeral ligament was present in 75% (18 of 24) of those cases or 9% of the study population. A smaller group of patients demonstrated a unique variant of normal capsulolabral anatomy that, for convenience, is termed the "Buford complex." This unusual variant was noted in 3 of the 200 (1.5%) shoulders and was distinguished by a "cord-like" middle glenohumeral ligament that originated directly from the superior labrum at the base of the biceps tendon and crossed the subscapularis tendon to insert on the humerus. There was no anterior-superior labral tissue present between this attachment and the midglenoid notch. This unusual-appearing anatomical variation may lead the surgeon to confuse this complex with a sublabral hole or a pathologic labral detachment. The labral tissue of the remaining three glenoid quadrants was normal. If the Buford complex is mistakenly reattached to the neck of the glenoid, as illustrated in our case example, severe painful restriction of rotation and elevation will occur.

けん板疎部損傷による外傷性肩関節下方脱臼の治療経験

We report a case of traumatic inferior dislocation of the shoulder due to tear of rotator interval and discuss therapeutic approaches.The case was a 16-year-old man who while playing volleyball, jumped at the ball and fell. His left arm was forced into abduction and he noted immediate pain and restriction of shoulder movement.On physical examination, tenderness and swelling were observed along the shoulder, and range of motion was severely limited. Roentgenograms showed inferior dislocation of the left shoulder in the resting position and an arthrogram showed dye projection into the rotator interval.Surgery was performed, with exploration of the rotator interval which was widely opened and the anteroinferior glenoid labrum and middle glenohumeral ligament attached. The coracohumeral ligament was not found. Glenoid labrum and middle glenohumeral ligaments were repaired and rotator interval was closed in the position of internal rotation.The post-operative course was satisfactory and limitation of external rotation did not occur, with the patient able to return to sporting activities.

Reconstruction of the antero-superior shoulder capsule with the subscapularis tendon: A case report

A 14-year-old boy presented with recurrent, anteroinferior, and multidirectional instability of his dominant shoulder. Examination with the patient under anesthesia demonstrated marked anterior and inferior translation when drawer testing was performed in adduction; however, abduction of the shoulder reduced the magnitude of humeral head translation in both these directions. Arthroscopy and open surgical dissection revealed the absence of any capsuloligamentous structures above the anterior band of the inferior glenohumeral ligament complex. This superior capsular defect could not be closed by a capsular shift procedure; therefore it was reconstructed with a portion of the subscapularis tendon. This case provides a clinical correlation of capsular anatomy with laxity on drawer testing. The glenohumeral laxity documented on examination with the patient under anesthesia supports experimental ligament-cutting studies that suggest the inferior glenohumeral ligament complex is the important stabilizer in abduction, whereas the superior and middle glenohumeral ligaments are more important in adduction.

Dynamic capsuloligamentous anatomy of the glenohumeral joint

Though many anatomic and biomechanical studies have been performed to elucidate capsuloligamentous anatomy of the glenohumeral joint, no previous studies have evaluated capsuloligamentous anatomy during rotator cuff contraction. The purpose of this study was to define and document the orientation and interrelationship between the glenohumeral ligaments during simulated rotator cuff contraction. Six fresh cadaveric shoulders were arthroscoped to document and grade ligamentous anatomy. The superior and middle glenohumeral ligaments and the anterior and posterior bands of the inferior glenohumeral ligament complex were labeled by an arthroscopicassisted technique with a linked metallic bead system. Shoulders were then placed onto an experimental apparatus that simulated rotator cuff function through computer-controlled servo-hydrolic actuators attached to the rotator cuff and biceps by a clamp and cable-and-pulley system. Simulated rotator cuff action and manual placement allowed shoulders to be placed into three positions of rotation (neutral, internal, and external) in three positions of scapular plane abduction (0°, 45°, 90°). Anteroposterior and axillary lateral plane radiographs were taken in each position to document orientation of all four ligaments. Both the superior and middle glenohumeral ligaments were maximally lengthened in 0° and 45° abduction and external rotation and appeared to shorten in all positions of abduction. The anterior and posterior bands of the inferior glenohumeral ligament complex maintained a cruciate orientation in all positions of abduction in the anteroposterior plane, except at 90° abduction and external rotation, where they are parallel. This cruciate orientation is due to the different location of the glenoid origin and humeral insertion of each band and may allow reciprocal tightening of each during rotation. The glenohumeral capsule is composed of discreet ligaments that undergo large charges in orientation during rotation. The superior and middle glenohumeral ligaments appear to complement the inferior glenohumeral ligaments, with the former tightening in adduction and the latter tightening in abduction. This relationship permits the large range of motion normally seen in the glenohumeral joint.

MR imaging of the normal shoulder: variants and pitfalls.

In 30 volunteers with normal shoulders, the following conclusions were made with regard to normal anatomic features at magnetic resonance (MR) imaging: (a) The supraspinatus tendon has low signal intensity, except for a 1-cm area with intermediate signal intensity in the region of the "critical zone." (b) The deltoid tendon attachment on the inferior surface of the acromion may simulate a subacromial spur if not imaged in continuity. (c) Fluid in the long head of the biceps tendon sheath is normal if not completely surrounding the tendon. (d) The anterolateral branch of the anterior humeral circumflex vessels in the proximal bicipital groove adjacent to the biceps tendon mimics fluid in the tendon sheath. (e) Continuity or obliteration of the subacromial-subdeltoid bursal fat plane is an unreliable diagnostic sign since the fat plane is often focally absent. (f) Fluid is not detected in subacromial-subdeltoid bursae. (g) Undercutting of the anterior glenoid labrum by hyaline cartilage or a closely apposed middle glenohumeral ligament may simulate an anterior labral tear.

Anterior shoulder stability: Contributions of rotator cuff forces and the capsular ligaments in a cadaver model

The purpose of this study was to quantify in a biomechanical model the contributions to shoulder joint stability that are made by tensions in the four tendons of the rotator cuff and by static resistance of defined portions of the capsular ligaments. A materials testing machine was used to directly determine anterior joint laxity by measurement of the force required to produce a standard anterior subluxation. Shoulders were tested in external or neutral humeral rotation. Data were analyzed by multiway analysis of variance with regression analysis. This model simulated tensions in the rotator cuff musculature by applying static loads at the tendon insertion sites acting along the anatomic lines of action. A load in any of the cuff tendons resulted in a measurable and statistically significant contribution to anterior joint stability. The contributions between different tendons were not significantly different and did not depend on the humeral rotation (neutral or external). In neutral humeral rotation the superior and middle glenohumeral ligaments together function equally with the inferior glenohumeral ligament as primary stabilizers against anterior humeral translation. The posterior capsule is a secondary stabilizer. The external rotation of the abducted humerus increases anterior stability by more than doubling the stability contribution from the inferior glenohumeral ligament. The stability contribution from the posterior capsule is larger in external rotation than in neutral rotation but is still of secondary magnitude. In external rotation the stability contribution of the anterior capsule, including the superior glenohumeral ligament and the middle glenohumeral ligament, becomes insignificant. The model presented here simulates the combined effect of two major sources of shoulder stability. This versatile model permits the direct measurement of the contributions to anterior shoulder stability that are made by tensions in the rotator cuff tendons and by static resistance of defined capsular zones. The use of multiple regression analysis-a standard statistical technique but one relatively new to the orthopaedic literature-permits quantitative determination of the contribution of each independent variable to the dependent variable, shoulder stability.

The contribution of the glenohumeral ligaments to anterior stability of the shoulder joint

The purpose of this study was to investigate the ligamentous stabilizing mechanisms preventing anterior instability in the glenohumeral joint. Six freshly thawed, unembalmed cadaveric shoulders were dissected, preserving the joint capsule and glenohumeral ligaments, the coracohumeral ligament, and the subscapularis tendon. Hall-effect strain transducers were placed on the superior, middle, and inferior glenohumeral ligaments. The humerus and scapula were fixed in a specifically designed mounting apparatus that allowed the glenohumeral joint to be placed in 0 degree, 45 degrees, or 90 degrees of abduction. The mounting apparatus was placed in a model TTC Instron Universal Testing Instrument, which applied an external rotation torque to the humerus. Strain produced in the three glenohumeral ligaments was recorded on a three-channel X-Y chart recorder. At 0 degree of abduction, the superior and middle glenohumeral ligaments developed the most strain. At 45 degrees of abduction, the inferior and middle glenohumeral ligaments developed the most strain, with considerable strain also being developed in the superior glenohumeral ligament. At 90 degrees of abduction, the inferior glenohumeral ligament developed the most strain, with strain also seen in the middle glenohumeral ligament.

Capsular ligaments of the shoulder

One hundred shoulders of 50 cadavers were dissected using the anterior approach. The normal appearance of the capsule, particularly the anterior superior, and the functions of the structures during passive motion were noted. There was a distinct capsular pattern with a Z formation which included the coracohumeral ligament and the superior, middle, and inferior glenohumeral ligaments. The middle and proximal capsular structures appeared to restrain external rotation. The coracohumeral ligament aided in restraint of external rotation at the lower range of abduction. The middle glenohumeral ligament was critical in restraining external rotation between 60 degrees and 90 degrees of abduction. It was readily identifiable except in a small percentage of individuals, who had a weak or absent ligament. The large capsular opening sometimes seen in shoulder repairs is due to an absent or attenuated middle glenohumeral ligament. Both the coracohumeral and middle glenohumeral ligaments were found to support the dependent arm.

死体における肩関節内剖検所見（中関節上腕じん帯を中心として）

In the arthroscopic examination of the shoulder joint, it is essential to dicide the findings as normal, normal variation or abnormal. Especially the anterior capsular potion has many normal variations. In order to clarify them, 48 shoulder joints of 24 cadavera were dissected. The frequency of the lack of middle glenohumeral ligament (m·G·H·L) was 27.1%. The average length of m·G·H·L was 15.1mm. 94.3% of m·G·H·L were membranous, whereas 5.7% were cord like.There are some bursaes which directly open into capsule. These bursaes are anatomically called B. infra coracoidea lateralis I, B. infra coracoidea lateralis II, B. infra coracoidea medialis, B. m. subscapularis, and B. tendinis m. subscapularis. All of them could be observed in our study. On these bursaes, names which are clinicaly used now is different from those which are used in anatomy. It must be emphasized that the difference in these names should be co-ordinated suitably soon.

Stabilizing mechanisms preventing anterior dislocation of the glenohumeral joint.

We investigated the stabilizing mechanism of the glenohumeral joint that prevents anterior dislocation by anatomical dissections of the subscapularis, the shoulder capsule, and the superior, middle, and inferior glenohumeral ligaments in thirty-six shoulders of embalmed cadavera. We also performed roentgenographic studies of ten unembalmed cadaver shoulders in which radiopaque markers were used to demonstrate the position, tightness, and laxity of the subscapularis muscle and of the middle and inferior glenohumeral ligaments during external rotation of the shoulder at zero, 45, and 90 degrees of abduction. The subscapularis muscle and the three glenohumeral ligaments were cut in different sequences to determine their relative contributions to stability (limitation of external rotation). The conclusions from these experiments were that at zero degrees of abduction, the subscapularis muscle stabilizes the joint to a large extent; at 45 degrees of abduction, the subscapularis, middle glenohumeral ligament, and anterosuperior fibers of the inferior glenohumeral ligament provide the stability; and as the shoulder approaches 90 degrees of abduction, the inferior glenohumeral ligament prevents dislocation during external rotation.

THE ANTERIOR CAPSULAR MECHANISM IN RECURRENT ANTERIOR DISLOCATION OF THE SHOULDER

1 . The concept of the capsular mechanism of the shoulder joint with regard to recurrent anterior dislocation of the shoulder has been defined and a survey of the literature presented. 2. An anatomical, including an embryological, investigation of shoulder joints with special reference to the structure and function of the glenoid labrum and to the variations in the arrangement of the gleno-humeral ligaments and the synovial recesses of the anterior capsular mechanism is reported. The labrum, which is generally believed to be a consistent, fibrocartilaginous structure, is shown to be a redundant portion of capsular tissue and a continuation of the capsule as it attaches to the osseous glenoid rim. The fibrocartilaginous element is confined to a small transition zone at the capsular attachment in the great majority of cases. The great variability in the arrangement of the gleno-humeral ligaments and synovial recesses is stressed, and it is shown that an anterior pouch of variable size is present when the middle gleno-humeral ligament is attached to the scapular neck and not to the labrum. 3. The basic lesions of the anterior capsular mechanism found at operation for recurrent anterior dislocation of the shoulder in twenty-five consecutive cases using a modified Bankart procedure with a standard anterior approach to the joint are reported, and the findings are correlated with the results of the anatomical investigation. In most cases the lesions were found to be of the Bankart type with or without avulsion of the periosteum of the scapular neck. In four cases, however, the soft-tissue attachment to the anterior glenoid rim was intact; in those cases a large synovial pouch was present and the middle gleno-humeral ligament was either not discernible or it arose from the scapular neck. In all cases a postero-lateral notch on the humeral head was palpable and laxity of the subscapularis could be demonstrated. When measured, the joint capacity was always greatly augmented. 4. The present work shows, from a basic standpoint, that Bankart's original idea that the recurrent state was due to the failure of healing of the fractured fibrocartilaginous glenoid labrum is no longer tenable. 5. Finally, the anomalous attachment or the insufficient development of the middle gleno-humeral ligament in certain cases of recurrent anterior shoulder dislocation is shown to provide the anatomical basis for the recurrent state in these cases; this is the weak area in the antero-inferior part of the capsule which has been described in the literature for the past hundred years. Thus we have returned to the original view of Hippocrates.