Shoulder Pathologies Flashcards
The rotator cuff is formed from which four muscles?
- Supraspinatus
- Infraspinatus
- Teres minor
- Subscapularis
Where do the following rotator cuff muscles have there insertion site?
- Supraspinatus
- Infraspinatus
- Teres minor
Greater tuberosity of humerus
What is the function of supraspinatus?
Initiation of abduction
What is the role of teres minor and infraspinatus?
External rotation at the shoulder joint
Where does the subscapularis have its insertion site and what is the role of this muscle?
Lesser tuberosity of the humerus
Internal rotation at shoulder joint
Collectively, what is the function of the rotator cuff muscles?
Pull humeral head into glenoid providing stability
What is impingement syndrome?
Pain due to tendons of the rotator cuff muscles due to compression in the subacromial space during movement
What is a painful arc?
Pain at between 60-120º on abduction
What are the causes of impingement syndrome?
- Tendonitis
- Subacromial bursitis
- AC OA with inferior osteophyte
- A hooked acromion
- Rotator cuff tear
Where does pain classically radiate in those with painful arc?
Deltoid and upper arm
Which clinical test is relevant for painful arc?
Hawkins-Kennedy test
(internally rotates the flexed shoulder which should re-create pain)
What are the treatment options for painful arc?
Conservative - NSAIDS, analgesia, physio, (up to 3) subacromial injections
Failure to improve with these methods requires subacromial decompression surgery which creates more space in the subacromial space
The classic history or rotator cuff tear involves what?
A sudden jerk in patients >40 which produces subsequent pain and weakness
In a rotator cuff tear, which muscle is primarily involved?
Supraspinatus
(large tears may also involve the subscapularis and infraspinatus)
What may be seen on examination for rotator cuff tears?
- Weakness of initiation of abduction (supraspinatus)
- Internal rotation weakness (Subscapularis)
- External rotation wekaness ( Infraspinatus)
- Wasting of supraspinatus