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

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) structure attached around the rim of the

glenoid cavity The glenoid fossa of the scapula or the glenoid cavity is a bone part of the shoulder. The word ''glenoid'' is pronounced or (both are common) and is from , "socket", reflecting the shoulder joint's ball-and-socket form. It is a shallow, pyri ...

on the

shoulder blade The scapula (: 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 side ...

. The

shoulder joint The shoulder joint (or glenohumeral joint from Greek ''glene'', eyeball, + -''oid'', 'form of', + Latin ''humerus'', shoulder) is structurally classified as a synovial joint, synovial ball-and-socket joint and functionally as a diarthrosis and m ...

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 of ...

. However, in bony terms the 'socket' (the

glenoid fossa The glenoid fossa of the scapula or the glenoid cavity is a bone part of the shoulder. The word ''glenoid'' is pronounced or (both are common) and is from , "socket", reflecting the shoulder joint's ball-and-socket form. It is a shallow, pyrifo ...

of the

scapula The scapula (: 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 side ...

) is quite shallow and small, covering at most only a third of the 'ball' (the

head of the humerus The humerus (; : humeri) is a long bone in the arm that runs from the shoulder to the elbow. It connects the scapula and the two bones of the lower arm, the radius and ulna, and consists of three sections. The humeral upper extremity consists o ...

). 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 (, "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 to form a single muscle bell ...

, 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 (superior labrum, anterior to posterior) is a tear where the glenoid labrum meets the

tendon A tendon or sinew is a tough band of fibrous connective tissue, dense fibrous connective tissue that connects skeletal muscle, muscle to bone. It sends the mechanical forces of muscle contraction to the skeletal system, while withstanding tensi ...

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 The elbow is the region between the upper arm and the forearm that surrounds the elbow joint. The elbow includes prominent landmarks such as the olecranon, the cubital fossa (also called the chelidon, or the elbow pit), and the lateral and t ...

flexion Motion, the process of movement, is described using specific anatomical terminology, anatomical terms. Motion includes movement of Organ (anatomy), organs, joints, Limb (anatomy), limbs, and specific sections of the body. The terminology used de ...

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, community health setting or in research. A clinician may diagnose, treat a ...

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 generate pictures of the anatomy and the physiological processes inside the body. MRI scanners use strong magnetic fields, magnetic field gradients, and ...

) or CT (

Computed Tomography A computed tomography scan (CT scan), formerly called computed axial tomography scan (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 or ...

) 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 is a medical specialty that uses manual and instrumental techniques to diagnose or treat pathological conditions (e.g., trauma, disease, injury, malignancy), to alter bodily functions (e.g., malabsorption created by bariatric surgery s ...

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 The Geisel School of Medicine is the medical school of Dartmouth College located in Hanover, New Hampshire. The fourth oldest medical school in the United States, it was founded in 1797 by New England physician Nathan Smith. It is one of the sev ...

'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