Rotator cuff tear
| Rotator cuff tear | |
|---|---|
 |
|
| Muscles on the dorsum of the scapula, and the triceps brachii | |
| Classification and external resources | |
| Specialty | Orthopedics |
| ICD-10 | M75.1, S46.0 |
| ICD-9-CM | 726.1 727.61, 840.4 |
| DiseasesDB | 32230 |
| MedlinePlus | 007207 |
| eMedicine | radio/894 pmr/125 radio/889 sports/115 |
A rotator cuff tear is a tear of one or more of the tendons of the four rotator cuff muscles of the shoulder. A rotator cuff 'injury' can include any type of irritation or overuse of those muscles or tendons, and is among the most common conditions affecting the shoulder.
The tendons of the rotator cuff, not the muscles, are most commonly involved, and of the four, the supraspinatus is most frequently affected, as it passes below the acromion. The role of the supraspinatus is to resist downward motion. The supraspinatus resists downward motion while the shoulder is relaxed as well as when carrying weight. Such a tear usually occurs at its point of insertion onto the humeral head at the greater tubercle. Even though the supraspinatus is the most commonly injured muscle of the four muscles in the rotator cuff, the other three muscles that comprise the rotator cuff, the infraspinatus, teres minor, and subscapularis, may also be injured.
The cuff is responsible for stabilizing the glenohumeral joint, abducting, externally rotating, and internally rotating the humerus. When shoulder trauma occurs, these functions can be compromised. Because individuals are highly dependent on the shoulder for many activities, overuse of the muscles can lead to tears, the vast majority again occurring in the supraspinatus tendon.
Many rotator cuff tears are asymptomatic. They are known to increase in frequency with age and the most common cause is age-related degeneration and, less frequently, sports injuries or trauma. Both partial and full thickness tears have been found on post mortem and MRI studies in those without any history of shoulder pain or symptoms. However, the most common presentation is shoulder pain or discomfort. This may occur with activity, particularly shoulder activity above the horizontal position, but may also be present at rest in bed. Pain-restricted movement above the horizontal position may be present, as well as weakness with shoulder flexion and abduction.
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Wikipedia