Glenoid Labrum: Difference between revisions
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The glenoid labrum is similar to the meniscus of the knee. It is a fibro-cartilaginous rubbery structure which encircles the glenoid cavity deepening the socket providing static stability to the glenohumeral joint. It acts and looks almost like a washer, sealing the two sides of the joint together.The labrum is described like a clock face with 12 o'clock being at the top (superior), 3 o'clock at the front (anterior), 6 o'clock at the bottom (inferior) and 9 o'clock at the back (posterior). Clinicans may reverse the 3 o'clock and 9 o'clock for left shoulder describing 3 o'clock at the back. This can be confusing, so the European Society of Shoulder & Elbow Surgeons (SECEC) has agreed to keep 3 o'clock at the front for either shoulder.<ref>https://www.shoulderdoc.co.uk/article/1399</ref> | The glenoid labrum is similar to the meniscus of the knee. It is a fibro-cartilaginous rubbery structure which encircles the glenoid cavity deepening the socket providing static stability to the glenohumeral joint. It acts and looks almost like a washer, sealing the two sides of the joint together.The labrum is described like a clock face with 12 o'clock being at the top (superior), 3 o'clock at the front (anterior), 6 o'clock at the bottom (inferior) and 9 o'clock at the back (posterior). Clinicans may reverse the 3 o'clock and 9 o'clock for left shoulder describing 3 o'clock at the back. This can be confusing, so the European Society of Shoulder & Elbow Surgeons (SECEC) has agreed to keep 3 o'clock at the front for either shoulder.<ref>https://www.shoulderdoc.co.uk/article/1399</ref> | ||
The glenoid labrum is approximately 4 mm thick and is round or triangular in cross section. | The glenoid labrum is approximately 4 mm thick and is round or triangular in cross section. | ||
The capsule of the glenohumeral joint attaches to the glenoid labrum. The glenoid labrum is continuous with: | The capsule of the glenohumeral joint attaches to the glenoid labrum. The glenoid labrum is continuous with: | ||
superiorly: tendon of the long head of biceps brachii<br>anteriorly:<br>anterior band of the inferior glenohumeral ligament<br>middle glenohumeral ligament (variably)<ref>https://radiopaedia.org/articles/glenoid-labrum</ref> | superiorly: tendon of the long head of biceps brachii<br>anteriorly:<br>anterior band of the inferior glenohumeral ligament<br>middle glenohumeral ligament (variably)<ref>https://radiopaedia.org/articles/glenoid-labrum</ref> | ||
== Clinical relevance == | == Clinical relevance == | ||
Most instabilities or pain syndromes are associated with injuries or morphologic changes in the glenoid labrum complex or long head of the biceps tendon origin. The first anatomic descriptions go back to Fick in 1910 and since then many authors have described the anatomy of these structures. It was Snyder who introduced the term SLAP lesions, classifying superior, anterior, posterior labrum changes into four grades. It is still unclear whether all of the described and arthroscopically observed changes are due to a post-traumatic, acquired lesion or whether anatomic variations can be present as well. In order to elucidate this problem, 36 cadaver shoulder joints were inspected macroscopically and sectioned for microscopic evaluation. Here the glenoid could be divided into an superior and an anterior- superior area demonstrating a wide variety of morphologic labral glenoid changes, while the dorsal and inferior sectors of the glenoid showed a relatively uniform anatomy of a firm labrum-glenoid bond. Four types of biceps tendon attachments could be identified similar to the description given by Vangsness. In addition, a variety of anterior-superior changes could be found. The sublabral hole as described by Esch in the clinical setting was found to be a physiologic variant. Precise knowledge of the anatomic morphology of the normal glenoid in its variations seems to be necessary to understand variants and allow for distinguishing between physiologic anatomic variants and pathoanatomic changes in imaging and the clinical setting.<ref name="Barthel T et al">https://www.ncbi.nlm.nih.gov/pubmed/12883756</ref> | |||
== Assessment == | == Assessment == | ||
Revision as of 08:58, 24 April 2017
Original Editor - Priyanka Chugh
Top Contributors - Priyanka Chugh, Kim Jackson, Lucinda hampton, Naomi O'Reilly, Wendy Snyders, 127.0.0.1 and Wanda van Niekerk
Description[edit | edit source]
The glenoid labrum (glenoid ligament) is a fibrocartilaginous 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.
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.[1]
Structure[edit | edit source]
The glenoid labrum is similar to the meniscus of the knee. It is a fibro-cartilaginous rubbery structure which encircles the glenoid cavity deepening the socket providing static stability to the glenohumeral joint. It acts and looks almost like a washer, sealing the two sides of the joint together.The labrum is described like a clock face with 12 o'clock being at the top (superior), 3 o'clock at the front (anterior), 6 o'clock at the bottom (inferior) and 9 o'clock at the back (posterior). Clinicans may reverse the 3 o'clock and 9 o'clock for left shoulder describing 3 o'clock at the back. This can be confusing, so the European Society of Shoulder & Elbow Surgeons (SECEC) has agreed to keep 3 o'clock at the front for either shoulder.[2]
The glenoid labrum is approximately 4 mm thick and is round or triangular in cross section.
The capsule of the glenohumeral joint attaches to the glenoid labrum. The glenoid labrum is continuous with:
superiorly: tendon of the long head of biceps brachii
anteriorly:
anterior band of the inferior glenohumeral ligament
middle glenohumeral ligament (variably)[3]
Clinical relevance[edit | edit source]
Most instabilities or pain syndromes are associated with injuries or morphologic changes in the glenoid labrum complex or long head of the biceps tendon origin. The first anatomic descriptions go back to Fick in 1910 and since then many authors have described the anatomy of these structures. It was Snyder who introduced the term SLAP lesions, classifying superior, anterior, posterior labrum changes into four grades. It is still unclear whether all of the described and arthroscopically observed changes are due to a post-traumatic, acquired lesion or whether anatomic variations can be present as well. In order to elucidate this problem, 36 cadaver shoulder joints were inspected macroscopically and sectioned for microscopic evaluation. Here the glenoid could be divided into an superior and an anterior- superior area demonstrating a wide variety of morphologic labral glenoid changes, while the dorsal and inferior sectors of the glenoid showed a relatively uniform anatomy of a firm labrum-glenoid bond. Four types of biceps tendon attachments could be identified similar to the description given by Vangsness. In addition, a variety of anterior-superior changes could be found. The sublabral hole as described by Esch in the clinical setting was found to be a physiologic variant. Precise knowledge of the anatomic morphology of the normal glenoid in its variations seems to be necessary to understand variants and allow for distinguishing between physiologic anatomic variants and pathoanatomic changes in imaging and the clinical setting.[4]
