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
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
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, Ive 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.

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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 the original muscle tissue, it is less flexible than the original muscle tissue, it forms in all different directions, not just along the lines of the original muscle, and many small nerve endings grow into the area. There are three grades of rotator cuff tendonitis or muscle strains, Grade I, Grade II, and Grade III. Grade I is a mild tear in the muscle which allows complete or almost complete range of motion with little or no pain. Grade II is a moderate tear of the muscle which decreases range of motion with moderate to severe pain. Grade III is a severe or complete tear of the muscle which limits range of motion.
A very common injury involving the soft tissues of the shoulder comprising of the subacromial space, it is normally referred to as an impingement syndrome. Instability impingement is when the tendons rub against the underlying bone. This can lead to abrasion, bleeding, swelling, pain and inflammation. This usually occurs in younger people typically 15-30 years old. The rotator cuff is irritated because the shoulder is loose in the socket, this often happens in baseball pitchers, swimmers, and other throwing athletes (2).
Rotator cuff tears (partial or total) are usually caused by unexpected or forceful movements and are more probable in people who have suffered degeneration from repetitive motion. Rotator cuff tears usually occur in people who have had tendonitis for a while and are starting to experience more weakness. It can also happen in someone who tries to lift something too heavy and feels a pop in the shoulder. This is the real reason that we see these types of injuries in pitchers, especially power pitchers (2).

Chapter 3
Many coaches and athletic trainers can help develop and carry out sound programs for preventing rotator cuff injuries. In athletes and non-athletes a conditioning programs should address flexibility, strength, and endurance of the shoulder muscles, particularly the scapular stabilizers and external rotators of the rotator cuff. The conditioning program must be tailored to the sport and fitness level of the individual. Learning the correct mechanics of the sport and choosing proper equipment are also important. Conditioning programs must be adjusted to avoid overuse injuries, and a proper warm-up and cool-down period should be routine with practice or competition. Such measures will not only help prevent injury, but will also make the individual more successful.

Shoulder injuries can be diminished by careful warm-up, stretching, strengthening of the shoulder muscles. When shoulder injury symptoms begin, early evaluation and treatment can prevent mild inflammation from becoming full blown rotator cuff impingement, or worse, a tear of the rotator cuff. A program of twenty minutes a day, of shoulder stretches and muscle strengthening exercises is recommended to increase performance and decrease injuries. It is extremely important to follow a sound preconditioning program during the off season for athletes. The same can be said about non-athletes also, you should always stretch prior to doing any heavy lifting or weekend recreational sports such as golfing, swimming, tennis, etc. If you follow a program of stretching and muscle strengthening exercises this can reduce your chances of injuring your shoulder.
Strengthening of the shoulder rotator cuff muscles is best performed by isolating each muscle group and selectively training that muscle. The subscapularis is the anterior stabilizer of the rotator cuff and responsible for internally rotating the shoulder. It is best strengthened by holding a hand weight in front of the body, with the arm flexed to 90 degrees, and rotating the hand to touch the belt. The exercise can be performed while lying on your back with the elbow close to your side and flexed ninety degrees.

Stretching of the shoulder rotator cuff muscles is easily performed both as treatment for inflammation and as a warm up before activity. Specific stretches are targeted to the desired activity. For example, for skiing, with a ski pole held firmly with one hand at the basket and one hand on the handle, with the arms held out straight, bring the pole from the waist to above the head, repeating the motion slowly to the limits of the range of motion. With the arms above the head, lean the ski pole as far as possible to the left and then to the right. This motion should be repeated with the arms in front of the body, both held out straight and in the flexed position. Many other shoulder stretches are available and most are helpful as long as sharp pain is avoided.

The logic behind stretching and strengthening the inflamed rotator cuff in order to speed healing and functional performance is as follows: the inflamed tissue is characterized by increased fluid between the cells, increased numbers of new blood vessels and inflammatory type cells. As a result of this inflammatory reaction, new collagen tissue is laid down in an effort by the body to heal the injured tissue. If the shoulder is immobilized during this time, the new collagen is laid down in a disorganized fashion, creating scar. The goal of gentle stretching, strengthening and anti-inflammatory medication, is to stimulate the cells to lay down collagen along the lines of stress, forming normal strong tendons. The combination of a good warm up, gentle stretching, strengthening below the limits of pain, icing after working out and anti-inflammatory medication has been consistently shown to speed recovery time in the strongest possible fashion.

Chapter 4
Clinical presentations of rotator cuff injuries include pain, weakness, and limitation of active motion. The pain tends to be located in the anterior, superior, and lateral aspects of the shoulder. Patients with acute inflammation of the rotator cuff have intermittent mild pain with overhead
activities. Patients who present with chronic inflammation of the rotator cuff have persistent, moderate pain with overhead activities. Patients with partial and full-thickness rotator cuff tears have persistent pain at rest that is often referred to the deltoid insertion. The symptoms of weakness and limitation of active motion may be the result of pain or a rotator cuff tear.

Physical examination will usually demonstrate in the subacromial space. Atrophy may be apparent in the supraspinatus or infraspinatus fossa in patients with full-thickness tears. Pain and muscle weakness can be evaluated by manual motor testing. One test that may be performed by your doctor is the subscapularis lift-off test of Gerber and Krushell (3) is performed with the arm internally rotated behind the back with the elbow flexed. The patient pushes away from the back against resistance, keeping the elbow flexed; inability to push away indicates rotator cuff injury. Other type of test is called the resistance test of the supraspinatus this test is performed with the arms abducted 90 degrees in scapular plane and internally rotated so that the thumbs point toward the floor. The examiner applies a downward force, while the patient attempts to maintain the arms parallel to the floor. Instability to resist the examiners downward force demonstrates isolated supraspinatus weakness. The drop arm test is another test that can help your doctor determine if you have a rotator cuff tear. This test detects wheather or not there are any tears. First, the doctor will instruct the patient to fully abduct the arm, then ask the patient to slowly lower it to there side. If there are tears in the rotator cuff, the arm will drop to the side from a position of about 90 degrees abduction. The patient still will not be able to lower their arm smoothly no matter how many times they try. If the patient is able to hold their arm in abduction, a gentle tap on the forearm will cause the arm to fall to there side (5).

Special diagnostic imaging, such as radiographic and magnetic resonance imaging (MRI), may aid in the evaluating the rotator cuff. The goal of any special test is to provide information regarding the presence of partial- or full-thickness tears of the rotator cuff, the size of the tear, and the quality of the muscle. Such information is especially important if surgery is being considered.
Radiographic evaluation of the shoulder starts with a routine shoulder series, including anteroposterior (AP) views with both internal and external rotation of the humerus. This view provides information that can help in determining fractures, dislocations, arthritic changes, and calcifying deposits.MRI is a very accurate test that can depict full thickness rotator cuff tears. The sensitivity and specificity for full thickness tears are 100% and 95%, respectively (4). One advantage of MRI is its ability to show the location, size, and retraction of the tear as well as existing pathology, such as labral tears. Another advantage is that it can also assess the quality of the muscle; in chronic tears, the muscle degenerates and fat infiltrates, preventing normal muscle performance even if the tendon is repaired to bone. MRI can aid in diagnosing partial tears with 85% sensitivity and 85% specificity (4). MRI has one major disadvantage along with the two advantages, the cost.

Chapter 5
Non-operative treatment is often effective for treating acute and chronic inflammation of the rotator cuff. Supervised program of physical therapy is a three phase program. The first phase of therapy aims to reduce rotator cuff inflammation and improve range of motion. Rest from the
inciting activity if often accompanied by short-term nonsteroidal anti-inflammatory drugs, if not contraindicated.

The second phase of physical therapy emphasizes full and painless range-of-motion exercise. Progressive isometric exercises, performed in the non-painful planes below shoulder level, should include the scapular stabilizers, the trapezius, levator scapulae, rhomboid major and minor, and serratus anterior muscles. Strengthening the stabilizers can restore proper motion.

The last phase of physical therapy introduces isotonic exercises to strengthen the rotator cuff, deltoid, and scapular stabilizers in order to stabilize the humeral head in the glenoid and prevent the dynamic, proximal migration leading to impingement. These exercises, initially done with light weights or elastic bands, are performed below shoulder level and with the arm at the side to prevent irritation of the inflamed cuff. Exercises that isolate specific cuff muscles, especially the supraspinatus at greater than 90 degrees abduction, should be avoided to prevent reinjury. In addition, the thumb should be turned upward during exercise to externally rotate the humerus, moving the greater tuberosity away from the acromion.

Prolotherapy is another non-operative procedure use in the treatment of rotator cuff injuries. What is Prolotherapy? Prolotherapy, which was developed over fifty years ago, is a natural non-surgical method of assisting the body to heal injured tendons and ligaments. “Prolo” stands for “proliferate”. In this case, Prolotherapy helps your body make new cells, which strengthen lax or torn tendons and ligaments. (Ligaments are the tough tissues which connect bones to bones, and tendons are the same kind of tissue which connects muscles to bones). You might wonder why you still have pain in an injured area or why that area remains weak, even after a healing period of weeks or months. The answer lies in the fact that both ligaments and tendons have very poor circulation, and it is this lack of blood supply which deprives them of the nutrients they need to heal properly. Now, these weakened areas may have little or no blood flow, but they have lots of nerves. When ligaments become relaxed and weak, these nerves within and around the ligaments and tendons become stretched and irritated.

Prolotherapy has been scientifically observed to increase the size of tendons and ligaments up to 40% (6). It has also been shown to increase their tensile strength by as much as 200% (6). No scar tissue is formed (as would be the case in surgical procedures). The tissue formed from Prolotherapy is healthy, strong, flexible ligament or tendon tissue. Once the ligament or tendon has been repaired by Prolotherapy, the nerves are no longer stretched or irritated, and the pain goes away.
How does Prolotherapy work? Prolotherapy works by strengthening the ligament or tendon where it attaches to the bone. This is the fibro-osseous junction. A small amount of a non-toxic “proliferant” solution (usually dextrose solution) is injected by means of a small needle into the tendon or ligament at the fibro-osseous junction and this stimulates the body to produce collagen, which strengthens the tissue. When the tissue is strengthened, the many nerves in that area are no longer stretched and irritated, and the pain is relieved. The pain relieved may also be far removed from the site of injury. This is called “referred pain”.
Prolotherapy is a very safe procedure when performed by a trained and highly skilled physician who has an in-depth knowledge of anatomy and experience using this injection technique. The use of needles involves risks, but complications from prolotherapy are rare. The solutions used have been shown to be safe and, as stated previously, do not contain cortisone. The most common side effect is discomfort due to the injections, as well as temporary soreness and stiffness. Although injection discomfort cannot be eliminated, this can be reduced by the use of oral medications for pain control and sedation. Many patients prefer not to be sedated because it makes them feels groggy and because a driver is required to and from the appointment. Topical freeze sprays, ice packs, or anesthetic cream can also reduce discomfort from skin penetration.

Prolotherapy is not an overnight cure. It cannot cure every condition, nor always eliminate 100% of one’s pain. Prolotherapy is an effective treatment for a multitude of conditions. There is no other treatment that replaces prolotherapy for strengthening weakened ligaments. It works by stimulating the body’s own healing process at the sites of injection. Healing occurs slowly but surely, and naturally. Multiple treatments are usually necessary to achieve maximum joint stability and long-lasting relief from pain.

Chapter 6
Once a rotator cuff injury has been diagnosed, various things can be done. The physician may require you to wear a sling for a few weeks (if the injury is bad enough), to allow the injured tissues to rest and begin healing. Most rotator cuff injuries can be resolved with rest, ice and non-surgical treatment. However, severe cases require surgery and many pitchers that are not ready to give up the game decide to take this route. There are usually two surgical options. One option is to use an arthroscopic, which works well with small tears. The second option is open surgery, which requires detaching the deltoid muscle. Combination surgeries also may be done.

The purpose of surgery is to relieve the symptoms and to repair the injured structure responsible for causing the symptoms. Rotator cuff surgery can be performed either by the traditional “open” procedure or arthroscopically. The surgeon will use either technique to view the shoulder structures and to remove damaged tissue and bone. If a partial or complete tear is identified, the margins of the tear will be re-approximated and sutured together.
The surgery itself consists of two parts. One involves the trimming away of some of the bone of the acromion and smoothing it out so that tendons dont rub against the bone when the arm is moved. The second part of the surgery is the repair of torn tendons. It involves removing parts of the tendon and the fluid filled sac to make more room so that the rotator cuff itself will not require that the torn edges of the supraspinatus tendon be sewn together over the humerus. If more than one tendon is actually torn the chance of recovery is greatly decreased. This is not risk free surgery. Nerve damage, pain, muscle and tendon damage, stiffness and even arthritis are not uncommon side effects. In addition the shoulder could require secondary surgery if healing fails to occur properly.

The two types of tears that would require surgery are partial-thickness and full-thickness rotator cuff tears. Partial-thickness tears can be approached in two ways. Tears affecting less than 40% of the total rotator cuff thickness can be treated by arthroscopic debridement with subacromial decompression to remove the anterior curve of the acromion that is impinging on the rotator cuff. Partial-thickness tears greater than 40% of the total cuff thickness over an area of more than 1cm should be excised and repaired. The repair of full-thickness tears vary. If a tear is less than 1cm long, it can be treated with debridement and subacromial decompression. Tears longer than 1cm should be treated subacromial decompression and repair.

Orthopedic surgeons use one of three general approaches (arthroscopic, mini-open deltoid splitting technique, and the classic open approach), depending on their preference and the size of the tear. No matter what the operative procedure, the goals of rotator cuff repair are to preserve the deltoid and make a good repair that allows early range-of-motion exercise and thus reduce the likelihood of a stiff shoulder.

Chapter 7
Recovery from shoulder surgery takes timeusually four to six months. Adhering to a physical therapy program is an important factor in the success of the surgery.Post-surgical rehabilitation varies with the surgical procedure performed. After surgery, rehabilitation with physical therapy is necessary to recover and regain as much use of the shoulder as possible. Most healthcare providers tell their patients to allow 6 months before they can expect to comfortably raise their arms above shoulder level and 12 months before they can use their arms to do work at a level above their head with their original strength.
Many rotator cuff injuries can be rehabilitated with a sling to immobilize your arm and shoulder. You also may be required to temporarily wear a shoulder brace. These devices help hold the shoulder in place while the rotator cuff heals. Your doctor also may prescribe rehabilitation exercises once the sling is removed. The major objectives of rehabilitation from a rotator cuff injury are to increase flexibility, obtain pain-free range of motion, and strengthen the muscles of the shoulders, upper back, front chest, and upper arms. In severe cases, you should avoid activity that causes shoulder pain altogether. In these cases, you can still maintain cardiovascular fitness by cycling, unless otherwise prescribed by your doctor. Surgery may be needed to repair a shoulder impingement or severe rotator cuff tear. In these cases, you will need to wear a sling or figure-of-eight strap while your shoulder heals. When your doctor decides you are ready, you may start range-of-motion and strengthening exercises. You may be referred to a physical therapist to assist you with these exercises and under no circumstance should you return to sports activity until your shoulder is fully healed. A physical therapy program usually begins with range-of-motion and resistive exercises, then incorporates power, aerobic and muscular endurance, flexibility, and coordination drills.

Patients with partial-thickness rotator cuff tears treated with arthroscopic subacromial decompression and debridement are placed in a simple sling. Active-assisted range-of-motion exercise begins immediately. Full active motion is achieved within two weeks. Resistive exercises and progressive strengthening start during the second week and continue for up to 12 weeks. Full return to sports activities requires two to three months of physical therapy, but high-level overhead athletes (pitchers, swimmers, and golfers) may take longer.

Following mini-open rotator cuff repair, patients use a simple sling only. Many orthopedic surgeons prescribe an abduction pillow to prevent stretching of the repair. When the tendon is repaired with the arm at the side, passive range-of-motion exercises begin immediately. Active-assisted starts at six weeks. Resistive exercises are then introduced. Full rehabilitation takes approximately four to six months.

The classic open technique requires prolonged postoperative protection of the deltoid, so rehabilitation is slower, taking about 9 to 12 months for full rehabilitation. The phases of rehabilitation, though delayed and extended, are essentially the same as those described above. Remember: the goal of rehabilitation is to return you to your sport or activity as soon as is safely possible. If you return too soon you may worsen your injury, which could lead to permanent damage. Everyone recovers from injury at a different rate. Return to your activity is determined by how soon your rotator cuff recovers, not by how many days or weeks it has been since your injury occurred.

Chapter 8
Most people think that rotator cuff injuries only happen to athletes. That is not always the case. Rotator cuff injuries happen to non-athletes as well as athletes. For example when an older person strains to life something a previously degenerated muscultendinous rotator cuff may rupture. The muscles and tendons that make up the rotator cuff can tear or become injured with the slightest fall. A fall on the shoulder may also tear a previously degenerated rotator cuff.
The rotator cuff muscles are susceptible to injury from falls and from overuse activities like throwing and swimming. The injuries are usually treatable with stretching, strengthening, and anti-inflammatories with full recovery expected. Careful differentiation between inflammation and tearing of the rotator cuff is mandatory. If the cuff is torn early arthroscopic or open repair is often helpful. Preventive conditioning exercises can diminish the frequency of these injuries.
The bottom line is rotator cuff injuries can occur in anyone who throws something or falls with the arm abducted. The injury is most common in people older than 45 years who strain themselves on weekends or holidays performing activities such as skiing, body surfing, and weight lighting. The mechanism of rotator cuff injury is indirect force to the abducted arm and repetitive microtramua to the shoulder joint. Shoulder injuries can be debilitating and often if caught early enough, easily treated. Seek out help if you are suffering from a shoulder injury. Theres no need to prolong the agony and perform at less than optimal capacity.

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(1998) Fourth Edition, Chapter Three
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3. Gerber C. Krushell RJ. Isolated Rupture of the Tendon of the Subscapularis Muscle. Bone
Joint Surgery (Br) 1991; 73 (3): 389-394
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Specificity and Predictive Value. 2002; 73(1):17-29
5. Hoppenfeld, Stanley. Physical Examination of the Spine and Extremities. 1976 pg. 33
6. Matson, Gary L., M.D., PLLC. Prolotherapy Can Effectively Reduce Chronic Pain. (2002)