Rotator cuff tears are tears of one or more of the four tendons of the rotator cuff muscles. A rotator cuff injury can include any type of irritation or damage to the rotator cuff muscles or tendons. Rotator cuff tears are among the most common conditions affecting the shoulder.
The tendons of the rotator cuff, not the muscles, are most commonly torn. Of the four tendons, the supraspinatus is most frequently torn as it passes below the acromion; the tear usually occurs at its point of insertion onto the humeral head at the greater tuberosity.
Tears of the rotator cuff tendon are described as partial thickness tears, full thickness tears and full thickness tears with complete detachment of the tendons from bone.
Partial thickness tears often appear as fraying of an intact tendon.
Full thickness tears are through-and-through tears. These can be small pin-point tears or larger button hole tears or tears involving the majority of the tendon where the tendon still remains substantially attached to the humeral head and thus maintains function.
Full thickness tears may also involve complete detachment of the tendon(s) from the humeral head and may result in impaired shoulder motion and function may be significantly affected.
Common medical studies used in diagnosing a rotator cuff tear include X-ray, MRI, double-contrast arthrography, and ultrasound techniques. A normal rotator cuff tear usually goes undetected with an X-ray, although bone spurs, which can pinch the rotator cuff tendons and result in a tear, can be captured. Moreover, if bone spurs are present, it suggests chronic severe rotator cuff disease. Double-contrast arthrography involves injecting contrast dye into the shoulder joint to detect leakage out of the injured rotator cuff. Arthrography and ultrasound are used, but depend heavily on the experience of a radiologist. The most effective and common diagnosis tool is magnetic resonance imaging (MRI), which can sometimes tell how large the tear is, as well as its location within the tendon. Furthermore, MRI enables the detection or exclusion of complete rotator cuff tears with a reasonable accuracy and is also suitable to diagnose further pathologies of the shoulder joint.
MRI of rotator cuff full-thickness tear.
The shoulder joint is made up of three bones: the shoulder blade (Scapula), the collarbone (Clavicle) and the upper arm bone (Humerus).
Muscles on the dorsum of the scapula, and the Triceps brachii.
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