What is the rotator cuff?
The rotator cuff is actually four muscles and their tendons which run from the scapula, or shoulder blade, to the humerus—the upper arm bone. (The top of the humerus is a ball shape and rests on the glenoid, or socket, to make the two parts of the shoulder joint.) These muscles perform the duty of lifting and rotating your arm as well as helping to keep the shoulder joint in place or stable.
The main rotator cuff muscle is the supraspinatus. This muscle is by far the most commonly affected by injuries and impingement. The supraspinatus is the rotator cuff muscle and tendon that lies directly under the acromion, or the bone on the top of the shoulder. When the arm is lifted out to the side or to the front, the supraspinatus may be pinched between the humerus and the acromion. This is known as impingement or impingement syndrome. Between the rotator cuff and the acromion lies the bursa-a slippery sack that lubricates those two structures.
Impingement also occurs when the supraspinatus weakens and the humerus can shift upwards towards the acromion. Some of us have a curved or hooked acromion known as a spur. This will reduce the space for the rotator cuff and bursa even more. Activities associated with impingement include overhead-motion sports-such as tennis, volleyball and baseball- repetitive job-related activities or just the duties of daily life.
Combine the lack of adequate space with a naturally poor blood supply to the supraspinatus and over time the rotator cuff can simply degenerate and give way or tear. Often referred to as 'wear and tear,' this represents a vicious cycle that leads to rotator cuff tears. Rotator cuff tears can also occur with trauma. This is often a fall onto the shoulder or outstretched hand. Other common ways to tear your rotator cuff are car accidents, throwing injuries or lifting heavy objects.
How do you know when you have impingement syndrome versus a rotator cuff tear?
That's the $64 million question. Both can be extremely painful. Both can be debilitating. Both will be painful with use of the arm, particularly lifting objects overhead. The pain is often on the outside of the upper arm and radiates downwards to the middle of the upper arm. Impingement will not lead to significant weakness, whereas those with a rotator cuff tear will be weak and won't be able to overcome the weakness. Night pain usually means there is a rotator cuff tear as well. If pain persists longer than two weeks you will benefit from an examination. Waiting too long often leads to other complications. The examination to differentiate a rotator cuff tear and impingement is difficult and is best performed by an experienced shoulder specialist. Most importantly, the exam should test your strength. Pain may come and go, but strength loss due to a rotator cuff tear does not improve. MRI studies can also be helpful. X-rays will show the acromial spur, but not rotator cuff injuries.
What do I do when shoulder pain occurs?
If you have a fall or a trauma, see your doctor or an orthopedic surgeon. The treatment of shoulder pain depends entirely on the cause of the pain. If you have impingement syndrome, nonsteroidal anti-inflammatories (NSAIDs) such as Advil or ibuprofen and waist-level exercises or physical therapy will often help you resolve the symptoms. The physical therapy will lower the humerus and decrease the intensity of the impingement. Occasionally, the pain just does not decrease. In this case, injections are very helpful. If your symptoms persist, smoothing the spur and shaving the bursa may be necessary to alleviate your symptoms. Although this is surgery, it is easily tolerated and recovery is swift.
If you have the more serious rotator cuff tear, the treatment often requires surgery. Physical therapy can help keep your range of motion, but lifting overhead will only damage your tear further. Also, time is not on your side. The longer you live with your rotator cuff tear, the larger the tear will become and the more your rotator cuff muscle will shrink or atrophy. In addition, if you have had more than two injections for bursitis (inflammation of the bursa) you should see an orthopedic surgeon because you likely will have a rotator cuff tear.
So, your rotator cuff tear means a visit to the orthopedic surgeon. Your surgeon will discuss options, which will include surgery if you wish to have your problem fixed. There are different ways to fix rotator cuff tears. Historically, an open incision was required to perform your repair. Now the gold standard has shifted to repairs that are performed entirely through the arthroscope. The scope is used to see the tear better because it is magnified and a more anatomic repair may be possible. In addition, arthroscopic repairs do not violate the deltoid muscle, which is an important assistant to the rotator cuff. With all arthroscopic repairs there are also fewer infections and many believe it is a less painful recovery—although this is difficult to prove. Arthroscopic rotator cuff repair is technically difficult and only few surgeons are able to perform it routinely, especially in cases where the tear is large or massive.
The bottom line?
If you have a rotator cuff injury, see your physician. Seek an orthopedic surgeon who is willing and able to offer you the state-of-the-art arthroscopic rotator cuff repair.
• Impingement or Rotator Cuff Tear = Pain and/or ache outside of shoulder to mid-upper arm
• Rotator Cuff Tear = Weakness and pain
• Impingement = No weakness
