Glenoid labrum

[1][2] The labrum is triangular in section; the base is fixed to the circumference of the cavity, while the free edge is thin and sharp.

Tearing of the labrum can occur from either acute trauma or repetitive shoulder motion such as in the sports of swimming, baseball and football.

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

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.

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.