The subacromial bursa is the synovial cavity located just below the
acromion, which communicates with the
subdeltoid bursa in most individuals, forming the so-called subacromial-subdeltoid bursa (SSB).
The SSB bursa is located deep to the
deltoid muscle
The deltoid muscle is the muscle forming the rounded contour of the human shoulder. It is also known as the 'common shoulder muscle', particularly in other animals such as the domestic cat. Anatomically, the deltoid muscle appears to be made up ...
and the coracoacromial arch and extends laterally beyond the humeral attachment of the
rotator cuff, anteriorly to overlie the
intertubercular groove, medially to the
acromioclavicular joint, and posteriorly over the rotator cuff. The SSB decreases
friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding (motion), sliding against each other. There are several types of friction:
*Dry friction is a force that opposes the relative la ...
, and allows free motion of the rotator cuff relative to the coracoacromial arch and the deltoid muscle.
French anatomist and surgeon
Jean-François Jarjavay is credited as the first to describe morbid processes of the SSB in 1867. Since then, histologic studies have documented that
synovial membrane
The synovial membrane (also known as the synovial stratum, synovium or stratum synoviale) is a specialized connective tissue that lines the inner surface of capsules of synovial joints and tendon sheath
A tendon sheath is a layer of synovial m ...
may undergo
inflammatory and/or degenerative changes and many now believe that they correspond to different stages in the spectrum of disease, with long-lasting inflammation leading to
degeneration
Degeneracy, degenerate, or degeneration may refer to:
Arts and entertainment
* ''Degenerate'' (album), a 2010 album by the British band Trigger the Bloodshed
* Degenerate art, a term adopted in the 1920s by the Nazi Party in Germany to descri ...
and
fibrosis
Fibrosis, also known as fibrotic scarring, is a pathological wound healing in which connective tissue replaces normal parenchymal tissue to the extent that it goes unchecked, leading to considerable tissue remodelling and the formation of permane ...
.
[Arend CF. Ultrasound of the Shoulder. Master Medical Books, 2013. Read a sample chapter on the pathogenesis of shoulder bursitis a]
ShoulderUS.com
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See also
* Subacromial bursitis
* Subcoracoid bursa
* Supra-acromial bursa
References
Sources
*
{{Authority control
Synovial bursae
Upper limb anatomy