Shoulder Anatomy Function: bones, ligaments, cartilage, tendons, bursa
The shoulder joint is formed where the humerus (upper arm bone) fits into the ( collarbone) meets the acromion in the acromioclavicular joint. There are actually four joints within the shoulder: the glenohumeral, Where the bones meet they are covered with articular cartilage, an extremely slippery. The ligaments, joint capsules and labrum are fixed structures that stabilise and.
The rotator cuff tendon and the adherent bursa, or lubricating tissue, can therefore be pinched when the arm is raised into a forward position. With repetitive impingement, the tendons and bursa can become inflamed and swollen and cause the painful situation known as "chronic impingement syndrome. When the rotator cuff tendon and its overlying bursa become inflamed and swollen with impingement syndrome, the tendon may begin to break down near its attachment on the humerus bone.
With continued impingement, the tendon is progressively damaged, and finally, may tear completely away from the bone. Why do some people develop impingement and rotator cuff disease when others do not? There are many factors that may predispose one person to impingement and rotator cuff problems. The most common is the shape and thickness of the acromion the bone forming the roof of the shoulder.
If the acromion has a bone spur on the front edge, it is more likely to impinge on the rotator cuff when the arm is elevated forward. Activities which involve forward elevation of the arm may put an individual at higher risk for rotator cuff injury.
Sometimes the muscles of the shoulder may become imbalanced by injury or atrophy, and imbalance can cause the shoulder to move forward with certain activities which again may cause impingement. Other than impingement, what else can cause rotator cuff damage? In young, athletic individuals, injury to the rotator cuff can occur with repetitive throwing, overhead racquet sports, or swimming.
Washington University Orthopedics
This type of injury results from repetitive stretching of the rotator cuff during the follow-through phase of the activity. The tear that occurs is not caused by impingement, but more by a joint imbalance. This may be associated with looseness in the front of the shoulder caused by a weakness in the supporting ligaments.
What kind of symptoms does a patient have when the rotator cuff is injured? The most common complaint is aching located in the top and front of the shoulder, or on the outer side of the upper arm deltoid area. The pain is usually increased when the arm is lifted to the overhead position. Frequently, the pain seems to be worse at night, and often interrupts sleep. Depending on the severity of the injury, there may also be weakness in the arm and with some complete rotator cuff tears the arm cannot be lifted in the forward or outward direction at all.
How is the diagnosis of rotator cuff disease proven? The diagnosis of rotator cuff tendon disease includes a careful history taken and reviewed by the physician, an x-ray to visualize the anatomy of the bones of the shoulder, specifically looking for acromial spur, and a physical examination.
Atrophy may be present, along with weakness, if the rotator cuff tendons are injured, and special impingement tests can suggest that impingement syndrome is involved. An MRI magnetic resonance imaging scan frequently gives the final proof of the status of the rotator cuff tendon. Although none of these tests is guaranteed accurate, most rotator cuff injuries can be diagnosed using this combination of exams.
What is the initial treatment for rotator cuff disease and impingement? If minor impingement or rotator cuff tendinitis is diagnosed, a period of rest coupled with medicines taken by mouth, and physical therapy will frequently decrease the inflammation and restore the tone to the atrophied muscles.Humerus and Scapula: Anatomy, Definition, Ligaments & Bones - Kenhub
Activities causing the pain should be slowly resumed only when the pain is gone. Sometimes a cortisone injection into the bursal space above the rotator cuff tendon is helpful to relieve swelling and inflammation. Application of ice to the tender area three or four times a day for 15 minutes is also helpful. What is the second line of treatment if the rotator cuff pain and weakness persist? If there is a thickened acromion or acromial bone spur causing impingement, it can be removed with a burr using arthroscopic visualization.
This procedure can often be performed on an outpatient basis, and at the same time, any minor damage and fraying to the rotator cuff tendon and scarred bursal tissue can be removed. Often this will completely cure the impingement and prevent progressive rotator cuff injury. If the rotator cuff is already torn, what are the options? When the tendon of the rotator cuff has a complete tear, the tendon often must be repaired using surgical techniques.
The choice of surgery, of course, depends on the severity of the symptoms, the health of the patient, and the functional requirements for that shoulder. In young working individuals, repair of the tendon is most often suggested.
In some older individuals who do not require significant overhead lifting ability, surgical repair may not be as important. If chronic pain and disability are present at any age, consideration for repair of the rotator cuff should be given. What will happen if the rotator cuff is not repaired? In some situations, the bursa overlying the rotator cuff may form a patch to close the defect in the tendon.
Although this is not true tendon healing, it may decrease the pain to an acceptable level. If the tendon edges become fragmented and severely worn, and the muscle contracts and atrophies, repair at that point may not be possible.
Sometimes in this situation, the only beneficial surgical procedure would be an arthroscopic operation to remove bone spurs and fragments of torn tissue that catch when the arm is rotated.
This certainly will not restore normal power or strength to the shoulder, but often will relieve pain. How is a major injury to the rotator cuff tendon repaired surgically?
Anatomy of the Shoulder
The arthroscope is extremely helpful when repairing rotator cuff tendons, but sometimes it is necessary to add a "mini-open" procedure if the tendon is completely torn. Using the arthroscope at the beginning of the case allows visualization of the interior of the joint to facilitate trimming and removal of fragments of torn cuff tendon and biceps tendon.
The next step utilizes the arthroscope to visualize the spur and thickened ligament beneath the acromial bone, while they are removed with miniature cutting and grinding instruments. If it is necessary to suture a rotator cuff tear which has pulled off the bone, a two-inch incision can be made directly over the tear that has been visualized and localized using the arthroscope. The deltoid muscle fibers can be spread apart so that strong stitches can attach the rotator cuff tendon back to the bone.
If the tear is minimally retracted, small suture screw anchors may be used arthroscopically or open. How is my shoulder treated after surgery? In a minor operation for impingement, the shoulder is placed in a simple sling.
If a full thickness tear of the rotator cuff was present and repaired, then the shoulder will be supported by an UltraSling or a SCOI postoperative brace. The brace is very helpful because it will allow exercise of the elbow, wrist, and hand at all times, and places the arm in a position that promotes better blood circulation and relieves stress on the repaired rotator cuff tissues.
In addition, the shoulder can be exercised in the brace much easier than when it is at the side in an immobilizer. What is the rehabilitation program after rotator cuff surgery?
Depending on the type of surgery performed, the program will allow a period of time for healing of the soft tissues followed by time to regain range of motion and then strengthen the shoulder muscles, but particularly the rotator cuff.
In minor tendinitis and impingement syndrome, the program takes approximately two to three months. If the rotator cuff tendon has been completely torn, it may take six months or more before the atrophied muscles can resume their function and the range of motion of the arm is restored.
Frequently, pain relief is much quicker and return to daily activities is often possible by two to three months. How successful is rotator cuff surgery? Again, every case is unique.
In the young, healthy person with a minor rotator cuff impingement, surgery is predictably successful. As the injury becomes more severe, such as with a large bone spur and fragmentation of the tendon, then a perfect result cannot be expected.
Since it is necessary to trim back the unhealthy tendon before reattaching it to the bone, a decreased range of motion of the shoulder will often result. Despite this, pain relief and return of strength are usually well worth the minor decreased mobility. The final outcome often depends on the willingness and ability of an individual patient to work on their postoperative physical therapy program.
Shoulder Instability Shoulder instability represents a spectrum of disorders, the successful management of which requires a correct diagnosis and treatment. The boundaries of this spectrum are represented by a subluxation event a partial dislocation which spontaneously reducesto a complete dislocation which often requires anesthesia to reduce the shoulder.
The majority of instabilities are traumatic in nature and the ball of the shoulder is unstable toward the front of the shoulder. It is this type of shoulder instability which we will concentrate on here. In order for a shoulder to dislocate, the very important and delicate balance of soft tissues ligaments, capsule and tendons around the shoulder must become damaged. The older a patient is at the time of initial injury the lower the chances are for developing recurrent instability.
It is for this reason we have become more aggressive in recent years in recommending early repair for this group of patients. We believe early repair reduces the likelihood of further injuring the shoulder with additional episodes of dislocation. The treatment for recurrent shoulder instability is usually surgical. This surgery is aimed at repairing the damaged capsule and ligaments directly.
This procedure can be done arthroscopically as an outpatient. The surgery is performed with a miniature lighted telescope and small instruments introduced into the shoulder joint through hollow cannulas. Advanced miniature anchors with suture attached are inserted precisely into the socket of the shoulder, and the torn ligaments are reattached to the socket. Complete healing from this procedure takes approximately months.
Calcium Deposits in the Shoulder Calcium deposits around the shoulder are a fairly common occurrence. Frequently they do not cause problems, but if they increase in size or become inflamed, then very severe pain may result. This collection of questions and answers is intended to explain this common shoulder problem and describe the methods we recommend for treatment in different situations. What is the cause of calcium deposits around the shoulder?
In most situations, there is no known cause for calcium deposits. Many people ask if their diet should be changed to reduce calcium intake. This should never be used as a form of treatment, since a normal balanced diet with a calcium supplement up to mg a day is healthy in a normal patient, particularly senior citizens and post-menopausal females. Who most commonly gets calcium deposits?
Calcium deposits occur most frequently in females between 35 and 65 years of age, but may occur in males as well. Do all calcium deposits cause problems? Many calcium deposits are present for years without causing any symptoms. Only when the deposit becomes large enough to pinch between the bones when the shoulder is elevated, does it cause pain.
Sometimes smaller deposits cause pain if they become acutely inflamed, especially when the calcium salts leak from the lesion into the sensitive bursal tissues.
Does a calcium deposit damage my shoulder? Some calcium deposits can cause erosion with the destruction of a portion of the rotator cuff tendon. Most calcium deposits remain on the outside of the rotator cuff tendon in the bursa and only cause problems because of their pain and catching.
Is the calcium deposit hard like a rock? Most early calcium deposits are very soft like toothpaste, but sometimes after being present for a long period of time, they do dry up and become chalk-like, sometimes even turning to bone.
What is the best treatment for a calcium deposit? When a calcium deposit becomes acutely inflamed, either because it ruptures and leaks calcium salts into the bursa, or because it pinches the bursa or rotator cuff, the symptoms can be quite severe. The acute inflammation can be treated with localized ice packs and rest in a sling, but oral anti-inflammatory medications are also helpful. A cortisone injection directly into the area of the calcium deposit may give relief within a few hours, when without it the acute severe pain may last for several days.
Do calcium deposits need removal? Cartilage can be hyaline, fibrocartilage and elastic and differ based on the proportions of collagen and elastin. Cartilage is a stiff but flexible tissue that is good with weight-bearing which is why it is found in our joints. Cartilage has almost no blood vessels and is very bad at repairing itself.
Bone is full of blood vessels and is very good at self repair. It is the high water content that makes cartilage flexible. The muscles on the lateral side of the shoulder allow movement and stabilize the joint. These muscles are strong on the upper and back sides of the arm, but not on the underside. A strong outside force in this area can cause the head of the humerus to slip out of the glenoid socket, called dislocation. Since there is little bony stability in this joint, a number of ligaments and other soft tissues stabilize this joint.
The superior AC ligament is the most important horizontal stabilizer. The coracoclavicular ligaments help stabilize the clavicle vertically. The Sternoclavicular Joint SC Most of the rotation occurs at the sternoclavicular joint and joint stability comes from the soft tissues.
The posterior sternoclavicular joint capsule is the most important structure for preventing forward and backward displacement of the medial clavicle.
The Rotator Cuff The rotator cuff consists of four muscle-tendon units that originate on the scapula and attach to the tuberosities of the humerus.
The anatomy of the shoulder
The rotator cuff is the primary stabilizer during movement of the GH joint. Both overuse and traumatic injuries to the rotator cuff are the most common problems in the shoulder girdle. The Subacromial Space The subacromial space is beneath the acromion and above the rotator cuff. The subacromial bursa outlines this space and provides frictionless gliding of the rotator cuff beneath the arch formed by the acromion and coracoacromion. Bone spurs on the underside of the acromion narrow this space, irritate the bursa and contribute to tears in the rotator cuff.
Bones of the Shoulder Girdle Click on image for larger labeled, picture. The bones of the shoulder girdle include the humerus, the scapula, and the clavicle. There are four articulations movements in the shoulder named for their anatomic locations: The scapula is the most complex of the bones in the shoulder and is part of the shoulder girdle.
The scapula floats on the rib cage, and is attached to it only with muscles. There are three landmarks on the scapula; the spine, acromion and coracoid processes. The roof of the glenohumeral joint is formed by the acromion. The acromion articulates with the clavicle forming the acromioclavicular AC joint. A spine divides the back of the scapula into two sections.
The muscles that attach below this spine are called infraspinatus muscles; the ones that attach above this spine are called supraspinatus muscles. The humerus is the ball part of the ball-and-socket joint. The head ball of the humerus articulates within the glenoid fossa. Below the humeral head is the anatomic neck which separates the head ball from the tuberosities.
Each tuberosity provides a place for the attachment for the anterior muscles of the rotator cuff—the 4 rotator cuff muscles originate from the scapula and their tendons attach at the humerus. The bicipital groove separates the tuberosities. Just below the tuberosities is the surgical neck of the humerus and is the most common area for fractures of the proximal humerus.
Clavicle Shoulder Blade — lateral view Clavicle collar bone. The clavicle originates at the sternum breastbone just above the first rib, and is held in place by the acromioclavicular ligament, several muscles and the coracoclavicular ligament. The clavicle helps hold the shoulder out to the side while allowing the scapula to move around. Shoulder Ligaments Click on image to see larger picture. There are several important ligaments about the shoulder girdle.
Ligaments are soft tissue structures that connect bones to bones. Ligaments are strong, tough bands that are not particularly flexible. Once stretched, they tend to stay stretched and if stretched too far, they snap. Ligaments, along with muscles and tendons, are the main source of stability for the shoulder. Shoulder ligaments also form the joint capsule that surround the glenohumeral joint.
These passive stabilizers serve to keep the joints of the shoulder from dislocating.