The glenoid labrum (glenoid ligament) is a fibrocartilaginous structure (not a

fibrocartilage Fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions. It owes its inflexibility and toughness to the former of these constituents, and its elasticity to the latter. It is the only type of ...

as previously thought) rim attached around the margin of the glenoid cavity in the

shoulder blade The scapula (plural scapulae or scapulas), also known as the shoulder blade, is the bone that connects the humerus (upper arm bone) with the clavicle (collar bone). Like their connected bones, the scapulae are paired, with each scapula on either ...

. The shoulder joint is considered a

ball and socket joint The ball-and-socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number o ...

. 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. 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 The biceps or biceps brachii ( la, musculus biceps brachii, "two-headed muscle of the arm") 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 t ...

, which gives off two fascicles to blend with the fibrous tissue of the labrum.

Structure

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 Slap or slapping may refer to: * Slapping (strike), a method of striking with the palm of the hand * Slapping (music), a musical technique used with stringed instruments * Slap tonguing, a musical technique used on wind instruments * ''Slap'' ( ...

(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. Because a SLAP lesion involves the biceps, pain and weakness may also be felt when performing elbow flexion with resistance.

Diagnosis

Clinician A clinician is a health care professional typically employed at a skilled nursing facility or clinic. Clinicians work directly with patients rather than in a laboratory or as a researcher. A clinician may diagnose, treat, and otherwise care for pa ...

s 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 Magnetic resonance imaging (MRI) is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio wave ...

) or CT (

Computed Tomography A computed tomography scan (CT scan; formerly called computed axial tomography scan or CAT scan) is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers ...

) 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.

Treatment

Detachment of the glenoid labrum often requires

surgery Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...

to reattach it to the glenoid fossa. Arthroscopic surgical techniques can also be used for more minor detachments.

References

External links

*
upper%20extremity/arthrogramaxial2
at the Dartmouth Medical School's Department of Anatomy *http://orthoinfo.aaos.org/topic.cfm?topic=a00426 *https://web.archive.org/web/20121119012737/http://www.orthospecmd.com/SLAPlesion.html *http://www.carlosguanchemd.com/wp-content/uploads/2012/08/Clinical-Testing-for-Tears-of-the-Glenoid-Labrum.pdf {{Authority control Ligaments of the upper limb