Shoulder problems including pain, are one of the more common reasons for physician visits for musculoskeletal symptoms. The shoulder is the most movable joint in the body. However, it is an unstable joint because of the range of motion allowed. This instability increases the likelihood of joint injury, often leading to a degenerative process in which tissues break down and no longer function well.
Shoulder pain may be localized or may be deferred to areas around the shoulder or down the arm. Disease within the body (such as gallbladder, liver, or heart disease, or disease of the cervical spine of the neck) also may generate pain that the brain may interpret as arising from the shoulder. Conversely, pain felt in the region of the shoulder blade or scapula nearly always has its origin in the neck.
- 1 Shoulder structures and functions
- 2 Diagnosis
- 2.1 Medical history and physical
- 2.2 Diagnostic tests
- 3 Dislocation
- 3.1 Description
- 3.2 Signs and diagnosis
- 3.3 Treatment
- 4 Separation
- 4.1 Description
- 4.2 Signs and diagnosis
- 4.3 Treatment
- 5 Sternoclavicular separation
- 5.1 Description
- 5.2 Signs and diagnosis
- 5.3 Treatment
- 6 Tendinitis, Bursitis, Impingement syndrome, and Rotator cuff tears
- 6.1 Description
- 6.2 Signs
- 6.3 Diagnosis
- 6.4 Treatment
- 6.5 Rotator cuff tear
- 7 SLAP tear (lesion)
- 7.1 Symptoms
- 7.2 Diagnosis
- 7.3 Treatment
- 7.4 Recovery
- 8 Frozen shoulder (adhesive capsulitis)
- 9 Fracture
- 9.1 Description
- 9.2 Signs and diagnosis
- 9.3 Treatment
- 10 Arthritis of the shoulder (glenohumeral joint)
- 10.1 Description
- 10.2 Signs and diagnosis
- 10.3 Treatment
- 11 Arthritis or osteolysis of the AC (acromioclavicular) joint
- 11.1 Description
- 11.2 Signs and diagnosis
- 11.3 Treatment
- 12 Temporary, emergency treatment
- 13 References
- 14 Related information
Shoulder structures and functions
The shoulder is composed of three bones: the clavicle (collarbone), the scapula (shoulder blade), and the humerus (upper arm bone) (see diagram). Two joints facilitate shoulder movement. The acromioclavicular (AC) joint is located between the acromion (part of the scapula that forms the highest point of the shoulder) and the clavicle. The glenohumeral joint, to which the term "shoulder joint" commonly refers, is a ball-and-socket joint that allows the arm to rotate in a circular fashion or to hinge out and up away from the body. The "ball" is the top, rounded portion of the upper arm bone or humerus; the "socket," or glenoid, is a dish-shaped part of the outer edge of the scapula into which the ball fits. Arm movement is further facilitated by the ability of the scapula itself to slide along the rib cage. The capsule is a soft tissue envelope that encircles the glenohumeral joint. It is lined by a thin, smooth synovial membrane.
The bones of the shoulder are held in place by muscles, tendons, and ligaments. Tendons are tough cords of tissue that attach the shoulder muscles to bone and assist the muscles in moving the shoulder. Ligaments attach shoulder bones to each other, providing stability. For example, the front of the joint capsule is anchored by three glenohumeral ligaments.
The rotator cuff is a structure composed of tendons that, with associated muscles, holds the ball at the top of the humerus in the glenoid socket and provides mobility and strength to the shoulder joint.
Four filmy sac-like structures called bursa permit smooth gliding between bone, muscle, and tendon. They cushion and protect the rotator cuff from the bony arch of the acromion.
Following are some of the ways doctors diagnose shoulder problems:
Medical history and physical
- Medical history (the patient tells the doctor about an injury or other condition that might be causing the pain).
Physical examination to feel for injury and discover the limits of movement, location of pain, and extent of joint instability. However, a systematic review of relevant research found that the accuracy of the physical examination is low.
Tests to confirm the diagnosis of certain conditions. Some of these tests include:
Arthrogram—Diagnostic record that can be seen on an x ray after injection of a contrast fluid into the shoulder joint to outline structures such as the rotator cuff. In disease or injury, this contrast fluid may either leak into an area where it does not belong, indicating a tear or opening, or be blocked from entering an area where there normally is an opening.
MRI (magnetic resonance imaging)--A non-invasive procedure in which a machine produces a series of cross-sectional images of the shoulder.
Other diagnostic tests, such as injection of an anesthetic into and around the shoulder joint.
The shoulder joint is the most frequently dislocated major joint of the body. In a typical case of a dislocated shoulder, a strong force that pulls the shoulder outward (abduction) or extreme rotation of the joint pops the ball of the humerus out of the shoulder socket. Dislocation commonly occurs when there is a backward pull on the arm that either catches the muscles unprepared to resist or overwhelms the muscles. When a shoulder dislocates frequently, the condition is referred to as shoulder instability. A partial dislocation where the upper arm bone is partially in and partially out of the socket is called a subluxation. In the medical community, dislocation is commonly referred to as luxation.
Signs and diagnosis
The shoulder can dislocate either forward, backward, or downward. Not only does the arm appear out of position when the shoulder dislocates, but the dislocation also produces pain. Muscle spasms may increase the intensity of pain. Swelling, numbness, weakness, and bruising are likely to develop. Problems seen with a dislocated shoulder are tearing of the ligaments or tendons reinforcing the joint capsule and, less commonly, nerve damage. Doctors usually diagnose a dislocation by a physical examination, and x rays may be taken to confirm the diagnosis and to rule out a related fracture.
Doctors treat a dislocation by putting the head of the humerus back into the joint socket (glenoid fossa) of the scapula — a procedure called manipulation and reduction (M&R). This is usually followed up with an x ray to make sure the reduction did not fracture the surrounding bones. The arm is then immobilized in a sling or a device called a shoulder immobilizer for several days. Usually the doctor recommends resting the shoulder and applying ice three or four times a day. After pain and swelling have been controlled, the patient enters a rehabilitation program that includes exercises to restore the range of motion of the shoulder and strengthen the muscles to prevent future dislocations. These exercises may progress from simple motion to the use of weights.
After treatment and recovery, a previously dislocated shoulder may remain more susceptible to reinjury, especially in young, active individuals. Ligaments are stretched and may tear due to dislocation. Torn ligaments and other problems resulting from dislocation can increase the chance of repeated dislocation. A shoulder that dislocates severely or often, injuring surrounding tissues or nerves, usually requires surgery to repair the damaged parts of the shoulder.
Sometimes the doctor performs surgery through a tiny incision into which a small scope (arthroscope) is inserted to observe the inside of the joint. After this procedure, called arthroscopic surgery, the shoulder is generally restrained by a sling for 3 to 6 weeks, while full recovery, including physical therapy, takes several months. Arthroscopic techniques involving the shoulder are relatively new and many surgeons prefer to repair a recurrent dislocating shoulder by the time-tested open surgery under direct vision. There are usually fewer repeat dislocations and improved movement following open surgery, but it may take a little longer to regain motion.
A shoulder separation occurs where the collarbone (clavicle) meets the shoulder blade (scapula). When ligaments that hold the AC (acromioclavicular) joint together are partially or completely torn, the outer end of the clavicle may slip out of place, preventing it from properly meeting the scapula. Most often the injury is caused by a blow to the shoulder or by falling on an outstretched hand. After injury it is hard to do a 180 degrees rotation.
Signs and diagnosis
Shoulder pain or tenderness and, occasionally, a bump in the middle of the top of the shoulder (over the AC joint) are signs that a separation may have occurred. Sometimes the severity of a separation can be detected by taking x rays while the patient holds a light weight that pulls on the muscles, making a separation more pronounced.
A shoulder separation is usually treated conservatively by rest and wearing a sling. Soon after injury, an ice bag may be applied to relieve pain and swelling. After a period of rest, a therapist helps the patient perform exercises that put the shoulder through its range of motion. Most shoulder separations heal within 2 or 3 months without further intervention. However, if ligaments are severely torn, surgical repair may be required to hold the clavicle in place. A doctor may wait to see if conservative treatment works before deciding whether surgery is required
Sternoclavicular separation Description
While not directly a shoulder problem, this may affect shoulder functionality due to problems with sternoclavicular rotation. A sternoclavicular separation occurs when the sternum separates from the clavicle at the sternoclavicular joint. Sternoclavicular separations (dislocation and subluxation) are rare  and generally caused by accident. If the clavicle is separated posteriorly (i.e. the clavicle separates and goes behind the sternum) the situation can be dangerous and the clavicle can cause damage to interior arteries, veins or organs.
Signs and diagnosis
An X-Ray or CT-Scan may be necessary to accurately diagnose a sternoclavicular separation.
Treatment consists of the standard use of plenty of rest, icing, NSAIDs and a sling. The joint may need to be reduced (I.E. put back in place), especially after posterior separations. In severe cases, surgery may be advised.
Tendinitis, Bursitis, Impingement syndrome, and Rotator cuff tears Description
These conditions are closely related and may occur alone or in combination. If the rotator cuff and bursa are irritated, inflamed, and swollen, they may become squeezed between the head of the humerus and the acromion. Repeated motion involving the arms, or the aging process involving shoulder motion over many years, may also irritate and wear down the tendons, muscles, and surrounding structures.
Tendinitis is inflammation (redness, soreness, and swelling) of a tendon. In tendinitis of the shoulder, the rotator cuff and/or biceps tendon become inflamed, usually as a result of being pinched by surrounding structures. The injury may vary from mild inflammation to involvement of most of the rotator cuff. When the rotator cuff tendon becomes inflamed and thickened, it may get trapped under the acromion. Squeezing of the rotator cuff is called impingement syndrome.
An inflamed bursa is called bursitis. Tendinitis and impingement syndrome are often accompanied by inflammation of the bursa sacs that protect the shoulder. Inflammation caused by a disease such as rheumatoid arthritis may cause rotator cuff tendinitis and bursitis. Sports involving overuse of the shoulder and occupations requiring frequent overhead reaching are other potential causes of irritation to the rotator cuff or bursa and may lead to inflammation and impingement.
Signs of these conditions include the slow onset of discomfort and pain in the upper shoulder or upper third of the arm and/or difficulty sleeping on the shoulder. Tendinitis and bursitis also cause pain when the arm is lifted away from the body or overhead. If tendinitis involves the biceps tendon (the tendon located in front of the shoulder that helps bend the elbow and turn the forearm), pain will occur in the front or side of the shoulder and may travel down to the elbow and forearm. Pain may also occur when the arm is forcefully pushed upward overhead.
Diagnosis of tendinitis and bursitis begins with a medical history and physical examination. X rays do not show tendons or the bursae but may be helpful in ruling out bony abnormalities or arthritis. The doctor may remove and test fluid from the inflamed area to rule out infection. Ultrasound scans are frequently used to confirm a suspected tendinitis or bursitis as well as rule out a tear in the rotator cuff muscles. Impingement syndrome may be confirmed when injection of a small amount of anesthetic (lidocaine hydrochloride) into the space under the acromion relieves pain.
The first step in treating these conditions is to reduce pain and inflammation with anti-inflammatory medicines such as aspirin, naproxen (Naprosyn), ibuprofen (Nurofen, Advil, Motrin, or Nuprin), or COX-2 selective inhibitors (Celebrex, Vioxx, or Mobic). In some cases the physical therapist will use ultrasound and electrical stimulation, as well as manipulation to improve blood flow. Gentle stretching and strengthening exercises are added gradually. If there is no improvement, the doctor may inject a corticosteroid medicine into the space under the acromion. While steroid injections are a common treatment, they must be used with caution because they may lead to tendon rupture. If there is still no improvement after 6 to 12 months, the doctor may perform either arthroscopic or open surgery to repair damage and relieve pressure on the tendons and bursae.
Posture and sleeping positions have been known to alleviate shoulder pain, possibly shoulder problems. For example, sleeping on one's side can cause pain due to prolonged compression of the shoulder joint. Sleeping on one's side without support can create or add to shoulder pain.
Rotator cuff tear
The term "rotator cuff" refers to a group of four tendons that blend together as they attach to the upper end of the arm bone (humerus). Normally these tendons transmit the force of muscles originating on the shoulder blade (scapula) to the arm providing motion and stability. The most commonly affected tendon is that of the supraspinatus muscle. Defects in the rotator cuff can come from an injury (cuff tear) or from degeneration (cuff wear). The degree to which a tendon is reparable depends on its quantity and quality. Degenerated tendons are often frail and retracted and may not be amenable to repair. Individuals that are elderly, smokers, or those having had cortisone injections often have weaker tendon tissue that fails without a significant injury. By contrast those whose tendon was torn by a substantial fall often have good quality tendon that can be repaired if surgery is performed promptly after the injury. The symptoms of rotator cuff disease include difficulty lifting the arm. Repair of a rotator cuff requires that the tendon be securely anchored to the bone at surgery and that the repair be protected for several months during healing. Further information that should be considered in the treatment of rotator cuff tears can be found at University of Washington School of Medicine.
SLAP tear (lesion)