|Anatomy of the
|Bursitis||Impingement||Rotator Cuff Tear|
|Dislocation||Subluxation & Instability||Acromioclavicular (AC) Separation||Links|
The shoulder is a muscular joint with a wide range of motion. The shoulder is frequently injured during athletics but it is also susceptible to inflammatory conditions. The function of the shoulder allows for a wide range motion but unfortunately this flexibility can lead to many problems and instability. An injury to the shoulder, or wear and tear in the parts of the shoulder, can lead to pain with movement or stiffness in the shoulder. To understand shoulder injures it is important to first learn more about the anatomy of the shoulder. Then we will discuss a few of the common injuries to the shoulder such as bursitis, impingement, rotator cuff tear, dislocation, subluxation and AC separation.
The shoulder is a complex joint composed of bones, muscles, tendons and ligaments. The three main bones of the shoulder include the humerus (upper arm), the scapula, and the clavicle (collarbone). The top of the shoulder is formed by a part of the scapula called the acromion. The shoulder is actually a combination of two separate joints. The first is the shoulder joint itself, which is a ball and socket joint. This type of joint allows the great range of motion of the shoulder by allowing for circumlocution and rotation. Together the acromion and the clavicle make up the acromioclavicular joint or the AC joint. The AC joint is a plane joint and allows for slip and slide activity.
The many muscles, tendons and ligaments within the shoulder stabilize these two joints. One group of muscles within the shoulder is the rotator cuff muscles. There muscles include the subscapularis, supraspinatus, infraspinatus and teres minor. Together these muscles help to move the shoulder and allow for rotation of the shoulder. The rotator cuff is responsible for raising the arm. The joint capsule is made by a group of ligaments that connect the humerus to the socket of the shoulder joint on the scapula. These ligaments are the main source of stability for the shoulder, and help to keep the shoulder from dislocating. Another important set of ligaments are the ones which connect the acromion to the clavicle and the clavicle to the scapula. There is also an outer layer of muscles, the deltoid, which surrounds the entire shoulder. The deltoid is responsible for lifting the arm once it is away from the body.
In between the rotator cuff and the deltoid is what is known as a bursa. A bursa is
simply a closed space between two moving surfaces that has a small amount of lubricating
fluid inside which helps to reduce friction inside the shoulder. In other words, the bursa
acts as a cushion within the shoulder allowing for smooth movement. Together, the bones,
muscle, ligaments and bursa make up the shoulder joint.
Many people are probably familiar with the term bursitis. The term bursitis means that the bursa within the shoulder joint is inflamed. The most common causes of bursitis overuse and strain. Each time we lift our arms the tendons and bursa within our shoulder rub together. This is a normal occurrence in day-to-day activities when one raises their arm above shoulder level. But continuously working with the arms raised overhead, repeated throwing activities, or other repetitive actions of the arm can cause the rubbing to become a problem. With overuse this can cause irritation and swelling of the bursa.
Some of the early symptoms of bursitis include generalized aching, pain when raising the arm out from the side or in front of the body and difficulty sleeping on the affected shoulder. Generally, there is localized or pinpoint pain over the affected area of the shoulder. The onset of pain may be gradual or sudden and movement in the joint may be limited. As the process continues, discomfort increases and the joint may become stiffer. Over time and with continued use, bursitis may lead to chronic inflammation and impingement syndrome.
The mainstay of treatment for bursitis is ice, rest, medications, such as aspirin and
ibuprofen, and physical therapy. If these measures fail to improve your pain, an injection
of cortisone into the bursa may reduce the inflammation and control the pain. Cortisone is
a very strong anti-inflammatory medication and can reduce the inflammation in the bursa
and tendons of the rotator cuff. It is very important to strengthen the rotator muscles,
which shoulder the shoulder joint. By doing so, one can decrease the stress on the bursa
with overhead use and increase the stability of the shoulder itself. Long-term management
of this problem should also address worksite alterations to reduce the need for overhead
The causes of impingement are very similar to those of bursitis. Each time we raise our arms the tendons and muscles that make up our shoulder rub together and over bony processes. The shoulder joint contains bursa, which helps to reduce this friction, but over time repetitive overhead motion can lead to a swollen and inflamed joint. There are a few risk factors, which also influence ones likelihood of developing impingement syndrome. The most common has to do with the shape and size of the acromion process. If the acromion has a spur on the end, the rotator cuff may impact the end of the bone spur and cause the muscles to become irritated.
Impingement syndrome results in pain with overhead activities such as throwing a ball or reaching for items on a high shelf. Frequently the pain from impingement is worst at night and interrupts normal sleep. There can be crepitus with overhead motion and loss of strength in the affected arm. With severe impingement, a person may have some weakness in the arm but the ability to lift the arm overhead is not lost.
The treatment for impingement syndrome is very similar to that of bursitis. It is
important for the patient to rest the affected shoulder and to ice the joint often.
Anti-inflammatory medications such as aspirin and ibuprofen should also be employed to
help reduce the pain and increase patient comfort. If the pain persists with over the
counter medication a cortisone injection can be given to reduce the inflammation and joint
pain. Lastly, physical therapy and lifestyle modification is the key to long-term
treatment. If symptoms of impingement continue, surgery may be needed to relieve the pain.
When surgery becomes necessary, the major goal of the surgery is to increase the space
between the acromion and the rotator cuff tendons. The first thing that must be done is to
remove any bone spurs under the acromion that are rubbing on the rotator cuff tendons and
the bursa. Usually a small part of the acromion may be removed as well to give the tendons
even more space and allow them to move without rubbing on the underside of the acromion.
Generally, the surgery can be done with arthroscopy as an outpatient procedure. After
surgery, the arm is placed in a sling and activity is kept at a minimum. Generally, full
recovery occurs in about 8-12 weeks with return to pre-injury athletic activities.
Rotator Cuff Tear
The four muscles that make up the rotator cuff of the shoulder are the supraspinatus, infraspinatus, teres minor and the subscapularis. Together these muscles provide a capsule that the shoulder sits in. When the rotator cuff muscles contract they allow the shoulder to move through a wide range of motion. The rotator cuff can be injuries by due to trauma, such as falling on an outstretched hand or by repetitive overhead use, such as throwing a softball. This is repetitive overhead motion can result in an impingement syndrome and lead to bone spurs. Either injury can result in a tear through the rotator tendon, which attaches the muscles to the humerus. Age is also a very important factor in rotator cuff injuries. During the third and fourth decades of life, the rotator muscles have decreased blood supply and show signs of degeneration. The weakened the rotator cuff muscles a have greater propensity to tear during minimal injury.
The symptoms of a rotator cuff tear are very similar to that of impingement syndrome. Rotator cuff tears cause two main problems - pain and weakness in the shoulder. With a rotator cuff tear one can have a complete or partial tear. When there is only partial tear of the tendons, you may have pain but can continue to move the arm in a normal range of motion. But when a complete rupture of the tendons occurs, you are unable to move the arm in a normal range of motion. A complete rotator cuff tear usually results in an inability to raise the arm away from the side under your own power. Rotator cuff tears can also cause difficulty sleeping due to pain. An MRI may be used to confirm the amount of damage to the rotator cuff and how much it is torn.
A full thickness tear in the muscles can result in a significant amount of pain and
disability for the patient. A rotator cuff tear cannot heal on its own and when it
interferes with work and recreational activities surgery is the treatment of choice.
Rotator cuff tears can be repair with arthoscopic surgery. First the arthoscope is used to
view the position of the tear and then to remove any bones spurs associated with
impingement syndrome. Next, an approximately two-inch incision is made over the shoulder.
Through this incision, the doctor can reattach the tendons to the humerus. The surgery
generally is an outpatient procedure and takes about two hours. After the surgery the arm
is placed in a sling and activity is kept to a minimum. It takes about 4-6 weeks for the
tendon to heal to the bone so it is important that the shoulder be kept relatively
immobile during this time period. It is also very important that the patient being a
formal physical therapy 10- 14 days after surgery. Passive motion is allowed at first and
then after 4-6 weeks active motion can be slowly resumed. Full recovery occurs in 3-6
The shoulder joint is made up of a capsule of muscles and ligaments that hold the head of the humerus within the shoulder socket. The ligaments that make up the joint capsule have a considerable amount of slack that allows the shoulder to move unrestricted though a large range of motion. Normally these ligaments stop the shoulder from moving too far and keep the head in the shoulder socket. Unfortunately, due to trauma, injury or an instable joint capsule, the shoulder can slip out of socket. If the shoulder slips completely out of the socket, it has become dislocated. Dislocation is the displacement of the two bones of the shoulder, the humerus and the scapula. Most of the time when dislocation occurs it is anterior, meaning that the humerus slips out of the front of the shoulder socket. Only 3 out of 100 dislocate posteriorly, or out the back.
The most common presenting symptom of shoulder dislocation is the feeling of the shoulder going out of place. A shoulder dislocation is usually very obvious. The primary signs and symptoms of dislocation includes pain, limitation of motion, swelling and joint deformity. The injury is usually very painful and the shoulder looks abnormal. When dislocated it is virtually impossible to move the shoulder due to extreme pain. After a dislocation the muscles surrounding the shoulder may be weak and instability may ensue. If the dislocation is acute it is usually due to considerable trauma to the shoulder. Chronic dislocations though, occur due to shoulder laxity and instability of the shoulder joint.
Acute dislocation causes an extreme amount of pain and anxiety. After dislocation, it
is important to get x-rays of the shoulder and reduce the shoulder as soon as possible.
Reducing the shoulder entails popping the humeral head back into the shoulder
socket. A doctor or health care provider should reduce the shoulder and evaluate the
shoulder for any bone or nerve injuries. Dislocation can lead to fractures of the bones in
the upper arm and nerve injuries. This can lead to sensory loss in the arm or a feeling of
paralysis in the deltoid muscle. Treatment of dislocation requires immobilization of the
shoulder for 3-6 weeks. As soon as pain permits, the patient with a dislocation should
begin physical therapy and strengthening of the shoulder capsule. Without proper treatment
and recovery recurrent dislocation and instability can occur.
Subluxation and Instability
Shoulder instability can be a common problem after a shoulder dislocation. Instability means that the shoulder is too loose and has a tendency to slip out of the socket. After initial injury and/or dislocation the shoulder the joint may remain unstable. Shoulder instability can also lead to subluxation of the shoulder. Subluxation is the feeling of the shoulder going out of place like a dislocation but the shoulder then reduces or goes back into place on its own. Instability is not always due to trauma or injury. It can arise from congenital or acquired abnormalities of the shoulder. Muscular imbalance due to a congenital dislocation or incongruent articulating surfaces of the bones such as in rheumatoid arthritis can cause shoulder instability.
Chronic instability causes several symptoms. Subluxation is the main symptoms of an instable shoulder. Subluxation may cause pain, swelling and limit the range of motion. One of the common positions when the shoulder may sublux is when the hand is raised above the head in a throwing motion. Patients may feel as if the shoulder is giving way with overhead activities. This creates a situation where you cannot trust the shoulder and may feel anxious in situations that require you to use the shoulder in the position. Over time the shoulder may become so loose that it dislocates frequently. In these cases when the shoulder completely dislocates, it is important to have the shoulder reduced by a medical professional.
Shoulder instability is best treated first by intense physical therapy, rest from
overhead activity, and anti-inflammatory medications. The rotator cuff muscles and the
ligaments surrounding the shoulder stabilize the shoulder. The rotator cuff muscles are
responsible for holding the head of the humerus in socket when the arm is used. If the
ligaments have been weakened by injury, the muscles can be strengthened to substitute for
them to some extent. If physical therapy alone is not enough to stabilize the shoulder
surgery may be needed. Surgery is aimed at tightening the ligaments that are loose,
usually the ligaments at the front of the shoulder. Suturing or stapling the ligaments
back into their original position on the humerus can provide the needed shoulder
stability. The surgery can be done by making a 2-3 inch incision on the front of the
shoulder or by arthoscopic methods. After surgery it imperative to allow the ligaments to
heal so that the shoulder is once again stable. The affected shoulder is immobilized for
1-2 weeks and then physical therapy is begun. The first six weeks of treatment consists of
increasing range of motion and the next six weeks of therapy focuses on strengthening the
surrounding muscles. Full recovery can be expected after 3-6 months.
Return to top
Acromioclavicular (AC) Separation
Together the acromion and the clavicle make up the acromioclavicular joint or the AC joint. The AC joint is a plane joint and allows for slip and slide activity. Injury to the AC joint can occur due to trauma or falling on the tip of the shoulder. The separation can vary in severity depending on the force of the trauma. There can be a complete or partial tear of the acromioclavicular ligament and/or the coracoclavicular (CC) ligament, which helps stabilize the AC joint. A type 1 injury results from mild trauma and produces a partial tear of the AC ligament. In contrast, a type 2 injury is when the AC ligament is completely torn but the CC ligament I still intact. This can result in subluxation or partial dislocation of the clavicle. Lastly, a type 3 injury is a complete tear of both the AC and CC ligaments. With a tear of these ligaments, the clavicle can completely dislocate.
Acromioclavicular joint separations cause point tenderness over the AC joint and there is usually a bump here. There is a decrease in the range of shoulder motion and strength due to pain. The severity of the injury determines the amount of pain and limitation of motion. With a type 1 injury there is focal pain and over the acromioclavicular ligament but minimal pain with motion. Type 2 injuries have moderate pain an unstable clavicle and moderate pain with motion. There may also be pain with palpation of both ligaments. With type 3 injuries the patient will not want to move their arm at all and will keep it close to their body. There is usually pain with any type of shoulder movement and the clavicle may be displaced.
Treatment is conservative with immobilization for a short period, ice, physical therapy
and exercise programs. Type 1 and 2 injuries are treated with 2-4 weeks of immobilization.
The treatment of type 3 injuries can be surgical or conservative. Conservative treatment
consists of reducing the dislocation and a sling to immobilize the joint. Surgical
treatment is aimed at reconstructing the CC ligament and reducing any clavicle
dislocation. Ice and anti-inflammatory agents are used with any AC separation no matter
the type of injury. Rehabilitation is begun when pain subsides and focuses on range of
motion and strengthening of the shoulder. Full recovery varies with the extent of injury
and return to regular activities is determined by pain and range of motion.
Questions on weg page content matters - email Carolyn @ firstname.lastname@example.org
Questions on weg page technical matters - email Mike @ email@example.com