Shoulder problems
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 referred to areas around the shoulder or down the arm. Other regions within the body also may generate pain that the brain may interpret as arising from the shoulder.
Shoulder structures and functions
The shoulder joint is composed of three bones: the clavicle, the scapula, and the humerus . Two joints facilitate shoulder movement. The acromioclavicular joint is located between the acromion 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.
Diagnosis
Following are some of the ways doctors diagnose shoulder problems:Medical history and physical exam
- Medical history. For shoulder problems the medical history includes the patient's age, dominant hand, if injury affects normal work/activities as well as details on the actual shoulder problem including acute versus chronic and the presence of shoulder catching, instability, locking, pain, paresthesias, stiffness, swelling, and weakness. Other salutary information includes OPQRST and a history of issues that could lead to referred pain including cervical spine disorders, heart attacks, peptic ulcer disease, and pneumonia. Standardized questionnaires like the Penn Shoulder Score that assess shoulder pain and function can aid in eliciting the required history to make a diagnosis and monitor condition progression.
- Physical examination of the shoulder to feel for injury and discover the limits of movement, location of pain, and extent of joint instability. The steps to elicit this information are inspection, palpation, testing range of motion, and performing special maneuvers. Information collected on inspection are asymmetry, atrophy, ecchymosis, scars, swelling, and venous distention. Palpation can help find pain and deformities, and should specifically include the anterior glenohumeral joint, acromioclavicular joint, biceps tendon, cervical spine, coracoid process, scapula, and sternoclavicular joint. Range of motion tests external and internal rotation, abduction and adduction, passive and active weakness, and true weakness versus weakness due to pain. The Apley scratch test is the most useful: touch opposite scapular by reaching behind the head for adduction and external rotation and behind the back for abduction and internal rotation. Finally, there are more specific maneuvers that can home in on a diagnosis, however their accuracy is limited.
Diagnostic tests
- Tests to confirm the diagnosis of certain conditions. Some of these tests include:
- * X-ray
- * 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 --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.
Dislocation
Description
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 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
Almost all shoulder dislocations are downwards and of these, 95 percent are in a forward direction. Clinically this is referred to as an anterior dislocation of the glenohumeral joint. 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 and bruising normally develop, and in some cases there may be numbness and muscle weakness. 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, but X-rays are taken to confirm the diagnosis and to rule out a related fracture and other complications. X-rays are also taken after relocation to ensure it is in the correct place.Treatment
Doctors treat a dislocation by putting the head of the humerus back into the joint socket of the scapula—a procedure called manipulation and reduction. 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 is inserted to observe the inside of the joint. After this procedure, called arthroscopic surgery, the shoulder is generally restrained by a sling for three to six 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.