What is a Rotator Cuff Tear?
The rotator cuff is a group of tendons in the shoulder joint providing support and enabling a wide range of motion. Major injury to these tendons may result in tear of these tendons, a condition called rotator cuff tear. It is one of the most common causes of shoulder pain in middle aged adults and older individuals.
Rotator cuff tears are one of the most common causes of shoulder pain and disability in the adult patient. Between 1998 and 2004, over 5 million office visits were attributable to shoulder pain and in 2008 alone, nearly 2 million people saw their doctor due to a torn rotator cuff. Unfortunately, rotator cuff tears appear to be a byproduct of the natural aging process, likely a blood supply issue to the tendon. In fact, by the time we are 60, there is a 50% chance of having at least a partial thickness tear and by the time we turn 80 that number jumps to 80% probability. To further compound the bad news, should you present with a rotator cuff tear that developed without an injury, you have a 50% chance of having a tear on the other shoulder that may or may not be painful at this time!
The rotator cuff itself is made up of four tendons (supraspinatus, infraspinatus, teres minor and subscapularis) and is responsible for rotation of the arm and the initial lift-off of the arm from your side. The majority of tears involve the supraspinatus tendon in isolation or a combination of supra- and infraspinatus tendon tears where it gradually pulls away from its attachment on the humeral bone (greater tuberosity).
Causes of rotator cuff tears are typically multifactorial but related to age, activity, falls or trauma, and smoking. More times than not, an injury cannot be recalled and the patient just wakes up with gradual pain on that side with activity and at rest.
Pain from a rotator cuff tear is typically localized to the front and lateral (side) portion of the shoulder. The pain can often times be localized further down the arm in the region of the deltoid muscle based on how pain is referred in our bodies. The pain is typically made worse with reaching above shoulder height or when weight is applied to the arm with the arm outstretched, such as when lifting a jug of milk from the refrigerator. Tears will also typically affect or impede sleep making it difficult to lie on that side at night. Although motion may be lost as a result of the tear, frequently shoulder motion can be completely normal even in the face of massive rotator cuff tears involving more than 2 tendons. In my experience, tears following a sudden fall or severe injury result in sudden loss of motion whereas tears that are gradual or degenerative in nature typically are associated with normal range of motion.
Clinical signs of a torn rotator cuff typically involve a combination of pain, mechanical impingement of the tear, and weakness of the torn tendon. Impingement can be checked by lifting your arm straight out in front, bringing it slightly towards center (adduction) of about 10 degrees and turning your thumb/forearm downward (pronation of arm). Pain with this maneuver (Hawkins’ test) is consistent with impingement but not necessarily indicative of a tear. Weakness of the supraspinatus tendon (most common tendon torn) can be checked by reaching the arm out to side to shoulder height, then bringing the arm forward thirty degrees and turning thumb downward. A person should be able to easily resist a downward directed force and pain and weakness of this test (Jobe’s maneuver) can indicate a tear. No one clinical test is indicative of a tear and often times a combination of your examination, history and possible further imaging (MRI/Ultrasound) are used to confirm the final diagnosis.
Clinical suspicion of a torn rotator cuff is typically confirmed with noninvasive imaging to include either a diagnostic ultrasound or MRI (magnetic resonance imaging). An ultrasound is an in office procedure which can quickly be used to help better determine the nature and source of your pain. Unlike an MRI, it also allows for a dynamic study meaning the tendon can be seen as you move or contract the muscle. Although the detail of the ultrasound has greatly improved with newer devices, the MRI continues to be the gold standard due to the better detail provided which can help determine if a large tear is still repairable (based on amount of retraction and/or fatty infiltration of tendon seen on MRI).
The rotator cuff itself consists of multiple layers, is less than half of an inch thick, and can have varying degrees of tearing thru the layers of the tendon. Tears seen on MRI, therefore, are usually described as either partial thickness or full thickness. A partial thickness tear means that a portion of the tendon is torn on either the bottom (articular) or top (bursal) side of the tendon however some of the fibers are still intact. This is the equivalent to a braided rope with fraying or partial tearing but some of the strands remain intact. A full thickness tear, in contrast, indicates that the entire tendon and all its layers in that area have pulled away from the bone. This knowledge is important as it factors heavily into your treatment options. A full thickness tear by nature will not heal due to the forces on the tendon. In fact, studies have proven that tears will get larger over time. A person with a full thickness tear has a greater than 40% chance of having a larger tear if rechecked two years following the diagnosis. Some tears can be completely asymptomatic; however, studies have noted that most tears do eventually become painful. While therapy can be effective in improving the pain from a tear, it will not restore the strength if left unrepaired. Furthermore, the tendon over time will begin to atrophy and this can be permanent even following a successful repair. Occasionally, tears that are ignored for a long period of time may become irreparable.
Non-operative management of rotator cuff tears consists of a combination of activity modification, physical therapy, anti-inflammatory medications (Aleve, Motrin Tylenol, etc.), and cortisone injections. Several studies have noted that non-operative treatment will help in approximately 60 to 70% of patients. It is therefore often the initial recommendation for patients with minimal demands on their shoulders. Patients with higher demands on their shoulders should be strongly considered for early operative treatment. The best results of rotator cuff repairs are in patients treated early, especially in the face of a traumatically torn tendon less than 3 months from the injury. Although effective at improving the pain, steroids should be used sparingly (every 3-4 months) and the patient should be educated and aware of the negative effects of multiple steroid injections into a full thickness tear which include more rapid tear progression and higher risk of failure (incomplete healing) if a repair is ever attempted.
Surgical treatment of rotator cuff tears involves repairing the tendon back to where it pulled away from the bone. This area of the bone is referred to as the “footprint” of the rotator cuff. Historically, this surgery was performed using a large incision over the shoulder which would require detachment of the deltoid muscle and subsequent repair. This “open” approach is often associated with more pain and prolonged rehabilitation. It also poses a risk of nonhealing of the deltoid muscle where it was detached from the bone for the exposure of the tendon leading to permanent disability.
With the advancement of arthroscopic surgery, even the largest of rotator cuff tears are now being treated using an all-arthroscopic minimally invasive technique. This can usually be performed thru a series of 4-7 percutaneous incisions that are less than 1cm (approx. ½ inch) placed around the shoulder to allow passage of small instruments. It is the equivalent of doing surgery while watching a television screen as your hands do the procedure, much like playing a video game. Most of the recent technological advancements in rotator cuff surgery have been directed at re-attaching the rotator cuff back to its anatomic “footprint”. Several biomechanical studies have concluded that the strongest repair of the rotator cuff is achieved by using a double row method. This means that the tendon is repaired using two sets of anchors (made of PEEK plastic) with two sets of sutures (braided polyester stitches) that are passed thru the tendon edge, tied, and crisscrossed over the top as it is repaired and pulled back to the bone. The sutures effectively create a web of compression which provides a stable and strong environment for healing.
Results of rotator cuff repairs continue to improve, as technological advancements facilitate arthroscopic repairs of rotator cuff tears of all sizes. With an emphasis on recreating normal anatomical attachment of the rotator cuff, all-arthroscopic double row rotator cuff repairs remain on the cutting edge of shoulder surgery. Unfortunately, not all repairs completely heal which remains one of the risks of surgical intervention with some studies reporting incomplete healing of a medium sized tear (1-3cm) upwards to 10-20%. The best chance of a successful outcome is based on multiple factors including age, the size of the tear, the timing of the repair, smoking cessation and compliance with postoperative activity modification.
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