SFCSeepersaud

Rotator Cuff

Anatomy of the Rotator cuff

The rotator cuff consists of a group of muscles and tendons that surround the shoulder joint. The muscles of the rotator cuff are the Subscapularis, Infraspinatus, Supraspinatus, and Teres Minor. The glenohumeral joint is a ball and socket joint. It is made up of a large spherical humeral head and a small glenoid cavity. This makes the joint mobile, but very unstable. Stabilization is provided by the non-contractile tissues of the glenohumeral joint (static stabilizers) which are the capsule, the labrum, the negative intraarticular pressure, and the glenohumeral ligaments. The contractile tissues are dynamic stabilizers, such as the rotator cuff and the long head of the biceps brachii.

The role of the rotator cuff is to stabilize the glenohumeral joint by compressing the humeral head against the glenoid. The rotator cuff muscle tendons blend with the joint capsule to form a musculotendinous collar that surrounds the anterior, posterior, and superior parts of the joint, leaving the inferior unprotected. This is important since most shoulder dislocations occur by the humerus sliding inferiorly through the unprotected part of the joint. Through arms movements, the rotator cuff muscles contract and prevent the sliding of the head of the humerus providing stability and allowing for a full range of motion. The rotator cuff also helps in the mobility of the shoulder joint through abduction, medial rotation and lateral rotation.

• Subscapularis- Medial (internal) rotation of the shoulder

• Supraspinatus- abduction of the arm

- Necessary for initial 0 to 15 degrees of shoulder abduction

-The deltoid muscles abducts the arm beyond 15 degrees

• Infraspinatus- Lateral (external) rotation of the shoulder

• Teres Minor- Lateral (external) rotation of the shoulder

During a physical examination, each of the muscles can be evaluated individually based on the movement for each of them.

Rotator cuff muscles and their locations

The subscapularis is the largest component of the posterior wall of the axilla. It helps to prevent the anterior dislocation of the humerus during abduction and it medially rotates the humerus. The bursa separates the subscapularis from the neck of the scapula. It is located at the subscapular fossa of the scapula.

• The supraspinatus muscle is the only muscle that is not a rotator of the humerus. It is located at the supraspinous fossa of the scapula.

• The infraspinatus is a lateral rotator of the humerus, the tendon of the muscles is often separated from the capsule of the glenohumeral joint by a bursa. It is located at the infraspinous fossa of the scapula.

• The teres minor is a long and narrow muscles that is covered by the deltoid. It is located at the lateral border of the scapula below the infraglenoid tubercle.

Rotator cuff Injuries

• Rotator cuff injuries can fall into three categories: Tendinitis, Bursitis and Rotator cuff strain/tear. Tendinitis, which is an injury that is caused by the overuse of the rotator cuff causing it to become inflamed. This is seen in tennis players due to their use of an overhead serve. Bursitis is another rotator cuff injury that is caused by an inflammation in the bursa. A bursa is a fluid-filled sac that is between the rotator cuff tendons and the bone. A rotator cuff strain or tear is caused by an overuse of the rotator cuff, tendons which connect the muscles to the bones can tear either partially or completely. This injury causes intense and immediate pain.

When a rotator cuff tendon is torn, the tendon is no longer attached to the head of the humerus. Most of the tears occur in the supraspinatus tendon, other parts of the rotator cuff may also be included too. The two types of tears are a Partial and Full-thickness tears. A Partial tear which is also called an incomplete tear, is damage to the tendon which does not fully separate it. A Full-thickness tear which is also called a complete tear, separates all of the tendon from the bone.

Physical examination

• Examination of the supraspinatus muscles is done with the Jobe’s test which is also known as the “empty can” test. This is done with a 90 degree abduction and internal rotation (by the thumb pointing to the floor), of the arm while pressing down on the arm. If it is painful or weakness it is positive.

• Examination of the infraspinatus muscle is done by lateral rotation against resistance, with the elbow flexed and with the arm in a neutral abduction position. If there is any pain or weakness it is positive.

• Examination of the teres minor muscle is done with the hornblower’s test. This is done with the arm at 90 degrees abduction and the elbow flexed at 90 degrees, doing a lateral rotation against resistance. If there is any pain or weakness it is positive.

• Examination of the subscapularis muscle is done by using the “lift off” test. During the lift off test, the patient brings their hands around the back towards the lumbar region and their palms are facing outwards. If the patient is unable to lift their hands away from their back the test is positive.

Rotator Cuff Tear symptoms

• Trouble raising your arm

• Pain when moving your arm certain ways or when you lie on it

• Weakness in your shoulder

• Unable to lift things like you normally do

• Clicking or popping sounds when you move your arm

Treatments

Nonsurgical treatment:

Rest, and limiting overhead activities. Doctors may prescribe a sling to help protect the shoulder and keep it still

• Avoiding activities that may cause pain and discomfort

• A non-steroidal anti-inflammatory medication, this includes drugs such as ibuprofen and naproxen to reduce pain and swelling.

• Strengthening exercises and physical therapy. Doing exercises to help with your movement and to strengthen your shoulder. An exercise programs may include stretching to improve flexibility and range of motion. By strengthening the muscles that support your shoulder, it can help to relieve pain and prevent injuries.

• A steroid injection of either a local anesthetic or a cortisone shot is is another way to treat if nothing is working. A cortisone is a very effective anti-inflammatory medicine.

Surgical treatment

Arthroscopic tendon repair is a procedure where a tiny camera (arthroscope) and tools are inserted through small incisions to attach the torn tendon to the bone.

• Open tendon repair is done by the surgeon making a larger incision to reattach the damaged tendon to the bone.

• Tendon transfer is a procedure where if the torn tendon is too damaged to be reattached to the arm bone, surgeons could decide to use a tendon that is close and use it as the replacement.

• A shoulder replacement is done for massive rotator cuff injuries. This helps to improve the artificial joint’s stability. A reverse shoulder arthroplasty is a procedure that installs the ball part of the artificial joint onto the shoulder blade and socket part onto the arm bone. This is a way that can help to improve the joint’s function and also reduce pain.

Prevention

Exercise the small and large muscles of the shoulder so that it can help to strengthen the rotator cuff.

• Maintaining a good posture. Leaning forwards with your head and shoulders can cause problems with the shoulder blade. This could lead to shoulder impingement issues.

• Avoid sleeping on your shoulder

• Avoid smoking because it decreases blood flow to the rotator cuff

• Avoid activities that have constant overhead arm motions. Stick to motions that would not put your shoulder in a position that would cause an injury.

• Do resistance exercises with more repetitions. It will help to strengthen the small muscles of the shoulder. Doing arm raises to the side with external rotation will also help.

• Massages with either a hot or cold compress will help to reduce the inflammation.