Understanding Rotator Cuff Injuries








Understanding Rotator Cuff Injuries: What they are, How to Prevent Them, How to Diagnosis Them, Non-surgical Treatment, Surgical Treatment, and Rehabilitation and Recovery time.


Submitted in partial fulfillment for the requirements for
SC102- Introduction to Human Anatomy


July 22, 2004


Table of Contents



Chapter Page


1. Introduction…………………………………………………………………………………… 3


2. Types of Rotator Cuff Injuries………………………………………………………………... 4


3. Preventing Rotator Cuff Injuries……………………………………………………………… 6


4. Diagnosing Rotator Cuff Injuries……………………………………………………………... 8


5. Non-Operative Treatment…………………………………………………………………… 10


6. Operative Treatment………………………………………………………………………… 12


7. Rehabilitation and Recovery Time………………………………………………………….. 14


8. Summary and Conclusion…………………………………………………………………… 16


Bibliography


Chapter 1


Many people think rotator cuff injuries are mainly associated with baseball players. That is not necessarily true, they can also happen to swimmers, weight lifters, tennis players, golfers, and in the non-athlete as well. Working in the military medical system, I’ve seen everyone from high school baseball players mainly pitchers to 70 year olds with rotator cuff injuries. There are many other shoulder injuries that could appear coincidentally or even mask a rotator cuff injury. These include bruises, separations, and bursitis.


The shoulder itself is a ball and socket joint. The ball is called the “head of the humerus” and the socket is called the “glenoid” or “scapula” (1). On top of this ball and socket joint is another bone known as the “acromion” (1). Next to the acromion is the “acromioclavicular joint” or the “AC joint” (1).


The Rotator Cuff is a group four of muscles that work in the shoulder joint to keep the humerus from popping out. This makes the Rotator Cuff critical for shoulder stability. There are four muscles in the Rotator Cuff: the “Teres Minor”, the “Infraspinatus”, the “Supraspinatus” and the “Subscapularis” (1). The supraspinatus is clinically the most important cuff tendon because it is involved, either alone or in combination with one or more additional tendons, in 95% of cuff tears (2). The main tendon of the supraspinatus forms within the mid portion of the muscle but lies progressively more anteriorly within the muscle as the supraspinatus courses laterally. The supraspinatus tendon follows the curvature of the superior humeral head and curves caudal to insert on the superior facet of the greater tuberosity. The supraspinatus tendon is approximately 9-11 mm thick at dissection but usually appears thinner (approximately 6-8 mm) on oblique coronal images in patients undergoing an MRI with the arm adducted and the cuff under tension (4). These muscles all work together to keep tension on the humerus, locking it into the shoulder joint.


The main functions of the Rotator Cuff are shoulder joint stabilization and external rotation of the humerus (rotating the arm to the rear). The Rotator Cuff is one of the primary areas of shoulder trauma; when someone has a shoulder injury; chances are very good that is related to injury in the Rotator Cuff. This trauma can be due to sudden injury or can be from overuse in undesirable movement patterns. The upright row exercise is a prime example of this undesirable movement pattern.


You might be asking why is the rotator cuff is so important. The group of muscles explained above help rotate the humerus and holds the shoulder in place by keeping the humerus head in the proper position inside the socket of the shoulder. The rotator cuff allows for everyday repetitive motions like scratching behind your head or back, painting, waxing, reaching, and lifting overhead. They are used extensively in athletic activities like throwing a ball, serving a tennis ball and driving a golf ball. If you have a shoulder pain or weakness that does not improve after a week or so you should see your health care professional.


Chapter 2


Rotator cuff injuries are usually broken up into the following categories: rotator cuff tendonitis and muscle strains, instability impingement, and rotator cuff tears (partial or total). Rotator cuff tendonitis or muscle strains are inflammation of the tendons which causes pain, swelling and stiffness. Injuries involving the rotator cuff muscles (Supraspinatus, Infraspinatus, Teres minor, and Subscapularis) are difficult to detect and isolate because these muscles, which reinforce the joint capsule, lie deep in the shoulder. Rotator cuff tendonitis usually occurs in people 30-80 years of age, and usually the weakness in the shoulder is only mild to moderate (2). When rotator cuff tendonitis heals the new tissue is called scar tissue. There are four problems with scar tissue: it is weaker than