Glenoid labrum

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Glenoidal labrum
Gray328.png
Lateral view of the shoulder showing the glenoid labrum (marked "glenoid lig.")
Details
Identifiers
Latin labrum glenoidale
TA98 A03.5.08.002
TA2 1765
FMA 23290
Anatomical terminology

The glenoid labrum (glenoid ligament) is a fibrocartilaginous structure (not a fibrocartilage as previously thought) rim attached around the margin of the glenoid cavity in the shoulder blade. The shoulder joint is considered a ball and socket joint. However, in bony terms the 'socket' (the glenoid fossa of the scapula) is quite shallow and small, covering at most only a third of the 'ball' (the head of the humerus). The socket is deepened by the glenoid labrum, stabilizing the shoulder joint. [1] [2]

Contents

The labrum is triangular in section; the base is fixed to the circumference of the cavity, while the free edge is thin and sharp.

It is continuous above with the tendon of the long head of the biceps brachii, which gives off two fascicles to blend with the fibrous tissue of the labrum.

Structure

Glenoid labrum. Schematic drawing of the transverse section. Morphologic variants of the glenoid labrum with relative distribution in percentage for the anterior labrum. a: 50%. Triangular with line of increased signal intensity along the hyalin articular cartilage. b: 20%. Rounded. c: 7%. Comma-shaped flattened. d: 3%. Absent. e: 15%. Cleaved. f: 8%. Notched. g: Central increase in signal intensity. h: Linear increase in signal intensity. The posterior labrum generally exhibits a triangular or rounded form. Glenoid labrum. Schematic drawing of the transverse section..jpg
Glenoid labrum. Schematic drawing of the transverse section. Morphologic variants of the glenoid labrum with relative distribution in percentage for the anterior labrum. a: 50%. Triangular with line of increased signal intensity along the hyalin articular cartilage. b: 20%. Rounded. c: 7%. Comma-shaped flattened. d: 3%. Absent. e: 15%. Cleaved. f: 8%. Notched. g: Central increase in signal intensity. h: Linear increase in signal intensity. The posterior labrum generally exhibits a triangular or rounded form.

Clinical significance

Injury

Tearing of the labrum can occur from either acute trauma or repetitive shoulder motion such as in the sports of swimming, baseball and football. Acute trauma may be from dislocation of the shoulder, direct blows to the shoulder, and other accidents of the sort. Tears are classified as either superior or inferior in regards to where the tear is in the glenoid cavity. A SLAP lesion (superior labrum, anterior to posterior) is a tear where the glenoid labrum meets the tendon of the long head of the biceps muscle. Symptoms include increased pain with overhead activity, popping or grinding, loss of strength, and trouble localizing a specific point of pain. [3] Because a SLAP lesion involves the biceps, pain and weakness may also be felt when performing elbow flexion with resistance.

Diagnosis

Clinicians can use any combination of the following manual tests to assist in determining if a labral tear has occurred; Jobe Relocation, O'Brien, Anterior Apprehension, Bicipital Groove Tenderness, Crank, Speed, and Yergason tests. As a general rule, abnormal pain experienced during any of these tests will indicate a positive result, or a tear of the glenoid labrum. All of the tests take advantage of the fact that the labrum meets the tendon of the long head of the biceps muscle, and thus will normally produce pain in the region if a tear is present. Additionally, clinicians may order an MRI (Magnetic Resonance Imaging) or CT (Computed Tomography) scan to be conducted utilizing contrast injections to highlight where tears may be present. However, due to inherent variability between humans, manual tests, when possible, are more accurate in determining the presence of a labral tear. [4]

Treatment

Detachment of the glenoid labrum often requires surgery to reattach it to the glenoid fossa. [5] Arthroscopic surgical techniques can also be used for more minor detachments. [5]

See also

Related Research Articles

<span class="mw-page-title-main">Scapula</span> Bone that connects the humerus (upper arm bone) with the clavicle (collar bone)

The scapula, also known as the shoulder blade, is the bone that connects the humerus with the clavicle. Like their connected bones, the scapulae are paired, with each scapula on either side of the body being roughly a mirror image of the other. The name derives from the Classical Latin word for trowel or small shovel, which it was thought to resemble.

<span class="mw-page-title-main">Rotator cuff</span> Group of muscles

The rotator cuff is a group of muscles and their tendons that act to stabilize the human shoulder and allow for its extensive range of motion. Of the seven scapulohumeral muscles, four make up the rotator cuff. The four muscles are the supraspinatus muscle, the infraspinatus muscle, teres minor muscle, and the subscapularis muscle.

<span class="mw-page-title-main">Biceps</span> Muscle on the front of the upper arm

The biceps or biceps brachii is a large muscle that lies on the front of the upper arm between the shoulder and the elbow. Both heads of the muscle arise on the scapula and join to form a single muscle belly which is attached to the upper forearm. While the biceps crosses both the shoulder and elbow joints, its main function is at the elbow where it flexes the forearm and supinates the forearm. Both these movements are used when opening a bottle with a corkscrew: first biceps screws in the cork (supination), then it pulls the cork out (flexion).

<span class="mw-page-title-main">Shoulder problem</span> Medical condition

Shoulder problems including pain, are one of the more common reasons for physician visits for musculoskeletal symptoms. The shoulder is the most movable joint in the body. However, it is an unstable joint because of the range of motion allowed. This instability increases the likelihood of joint injury, often leading to a degenerative process in which tissues break down and no longer function well.

<span class="mw-page-title-main">Shoulder</span> Part of the body

The human shoulder is made up of three bones: the clavicle (collarbone), the scapula, and the humerus as well as associated muscles, ligaments and tendons. The articulations between the bones of the shoulder make up the shoulder joints. The shoulder joint, also known as the glenohumeral joint, is the major joint of the shoulder, but can more broadly include the acromioclavicular joint. In human anatomy, the shoulder joint comprises the part of the body where the humerus attaches to the scapula, and the head sits in the glenoid cavity. The shoulder is the group of structures in the region of the joint.

<span class="mw-page-title-main">Shoulder joint</span> Synovial ball and socket joint in the shoulder

The shoulder joint is structurally classified as a synovial ball-and-socket joint and functionally as a diarthrosis and multiaxial joint. It involves an articulation between the glenoid fossa of the scapula and the head of the humerus. Due to the very loose joint capsule that gives a limited interface of the humerus and scapula, it is the most mobile joint of the human body.

<span class="mw-page-title-main">Subscapularis muscle</span> Large triangle muscle of the shoulder

The subscapularis is a large triangular muscle which fills the subscapular fossa and inserts into the lesser tubercle of the humerus and the front of the capsule of the shoulder-joint.

<span class="mw-page-title-main">Shoulder girdle</span> Set of bones which connects the arm to the axial skeleton on each side

The shoulder girdle or pectoral girdle is the set of bones in the appendicular skeleton which connects to the arm on each side. In humans it consists of the clavicle and scapula; in those species with three bones in the shoulder, it consists of the clavicle, scapula, and coracoid. Some mammalian species have only the scapula.

<span class="mw-page-title-main">SLAP tear</span> Medical condition

A SLAP tear or SLAP lesion is an injury to the glenoid labrum. SLAP is an acronym for "superior labral tear from anterior to posterior".

<span class="mw-page-title-main">Glenoid fossa</span> Part of the shoulder

The glenoid fossa of the scapula or the glenoid cavity is a bone part of the shoulder. The word glenoid is pronounced or and is from Greek: gléne, "socket", reflecting the shoulder joint's ball-and-socket form. It is a shallow, pyriform articular surface, which is located on the lateral angle of the scapula. It is directed laterally and forward and articulates with the head of the humerus; it is broader below than above and its vertical diameter is the longest.

<span class="mw-page-title-main">Olecranon fossa</span> Deep triangular depression on the posterior end of the humerus

The olecranon fossa is a deep triangular depression on the posterior side of the humerus, superior to the trochlea. It provides space for the olecranon of the ulna during extension of the forearm.

<span class="mw-page-title-main">Radial tuberosity</span>

Beneath the neck of the radius, on the medial side, is an eminence, the radial tuberosity; its surface is divided into:

<span class="mw-page-title-main">Coracoacromial ligament</span> Ligament between the coracoid process and the acromion of the scapula

The coracoacromial ligament is a strong triangular ligament between the coracoid process and the acromion. It protects the head of the humerus. Its acromial attachment may be repositioned to the clavicle during reconstructive surgery of the acromioclavicular joint.

<span class="mw-page-title-main">Supraglenoid tubercle</span> Region of the scapula from which the long head of the biceps brachii muscle originates

The supraglenoid tubercle is a region of the scapula from which the long head of the biceps brachii muscle originates. It is a small, rough projection superior to the glenoid cavity near the base of the coracoid process. The term supraglenoid is from the Latin supra, meaning above, and glenoid, meaning socket or cavity.

<span class="mw-page-title-main">Acetabular labrum</span> Ring of cartilage that surrounds the acetabulum of the hip

The acetabular labrum is a ring of cartilage that surrounds the acetabulum of the hip. The anterior portion is most vulnerable when the labrum tears.

<span class="mw-page-title-main">Dislocated shoulder</span> Injury

A dislocated shoulder is a condition in which the head of the humerus is detached from the shoulder joint. Symptoms include shoulder pain and instability. Complications may include a Bankart lesion, Hill-Sachs lesion, rotator cuff tear, or injury to the axillary nerve.

Shoulder surgery is a means of treating injured shoulders. Many surgeries have been developed to repair the muscles, connective tissue, or damaged joints that can arise from traumatic or overuse injuries to the shoulder.

<span class="mw-page-title-main">Bankart lesion</span> Medical condition

A Bankart lesion is a type of shoulder injury that occurs following a dislocated shoulder. It is an injury of the anterior (inferior) glenoid labrum of the shoulder. When this happens, a pocket at the front of the glenoid forms that allows the humeral head to dislocate into it. It is an indication for surgery and often accompanied by a Hill-Sachs lesion, damage to the posterior humeral head.

Humeral avulsion of the glenohumeral ligament (HAGL) is defined as an avulsion of the inferior glenohumeral ligament from the anatomic neck of the humerus. In other words, it occurs when we have disruption of the ligaments that join the humerus to the glenoid. HAGL tends to occur in 7.5-9.3% of cases of anterior shoulder instability. Making it an uncommon cause of anterior shoulder instability. Avulsion of this ligamentous complex may occur in three sites: glenoid insertion (40%), the midsubstance (35%) and the humeral insertion (25%). Bony humeral avulsion of the glenohumeral ligament (BHAGL) refers when we have HAGL with bony fracture.

Yergason's test is a special test used for orthopedic examination of the shoulder and upper arm region, specifically the biceps tendon.

References

PD-icon.svgThis article incorporates text in the public domain from page 319 of the 20th edition of Gray's Anatomy (1918)

  1. ↑ Carter, Kevin.; Mudigonda, Sanjay. (1 January 2009), Weissman, Barbara N. (ed.), "Chapter 5 - Arthrography and Injection Procedures", Imaging of Arthritis and Metabolic Bone Disease, Philadelphia: W.B. Saunders, pp. 60–80, doi:10.1016/b978-0-323-04177-5.00005-7, ISBN   978-0-323-04177-5 , retrieved 25 October 2020
  2. ↑ Lodha, Sameer; Mazloom, Sean; Resler, Amy G.; Frank, Rachel M.; Ghodadra, Neil S.; Romeo, Anthony A.; Kim, Jonathan Yong; Jadgchew, R. Jason; Provencher, Matthew T. (1 January 2018), Giangarra, Charles E.; Manske, Robert C. (eds.), "24 - Shoulder Instability Treatment and Rehabilitation", Clinical Orthopaedic Rehabilitation: a Team Approach (Fourth Edition), Philadelphia: Content Repository Only!, pp. 130–157.e1, ISBN   978-0-323-39370-6 , retrieved 25 October 2020
  3. ↑ Romeyn, Richard; Manske, Robert C. (1 January 2018), Giangarra, Charles E.; Manske, Robert C. (eds.), "21 - Importance of the History in the Diagnosis of Shoulder Pathology", Clinical Orthopaedic Rehabilitation: a Team Approach (Fourth Edition), Philadelphia: Content Repository Only!, pp. 100–109.e1, ISBN   978-0-323-39370-6 , retrieved 25 October 2020
  4. ↑ Guanche, C (2003). "Clinical Testing for Tears of the Glenoid Labrum" (PDF). Arthroscopy. 19 (5): 517–523. doi:10.1053/jars.2003.50104. PMID   12724682 . Retrieved 28 November 2016.
  5. 1 2 Watling, J. P.; Brabston, E. W.; Padaki, A. S.; Ahmad, C. S. (1 January 2015), Greiwe, R. Michael (ed.), "1 - Anterior instability: Shoulder dislocations, instability, and the labrum", Shoulder and Elbow Trauma and its Complications, Woodhead Publishing Series in Biomaterials, Woodhead Publishing, pp. 3–22, doi:10.1016/b978-1-78242-449-9.00001-7, ISBN   978-1-78242-449-9 , retrieved 25 October 2020
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