Shoulder Surgery

The shoulder joint is the joint with greatest range of motion of any joint. Because of this wide range of motion, one is able to place a hand in many advantageous positions. But the wide range of motion is at the expense of stability. A lack of stability results in a joint that is loose with a tendency to dislocate (come out of its socket). The joint and the tendons about the joint are subjected to considerable wear and tear leading to degeneration of the joint surface giving rise to arthritis and tears in the supporting tendons (the tough fibrous tissue through which a muscle attaches to bone) 郑州市骨科医院关节病治疗中心司文腾

Anatomy

• The shoulder is made up of three bones, the scapula, clavicle and humerus
  1. The scapula (shoulder blade) lies on the back of the chest and has a triangular shape. The part of the scapula at the shoulder forms a shallow socket (joint depression), the glenoid. The glenoid is surrounded by a soft tissue called the labrum that acts to deepen the socket into which the head of the humerus fits (Figure 1A and 1B)
  2. The clavicle (collar bone) is a long narrow bone that bridges between the sternum (breastbone) and the shoulder
  3. The humerus is the bone of the upper arm that lies between the shoulder and the elbow. At the shoulder it has a rounded head that fits into the glenoid

Figure 1a - The scapula, humerus and clavicle are the three bones that make up the shoulder. As seen from the front	Figure 1b - As seen from the back

• There are two joints in the shoulder
  1. Glenohumeral joint is made up of the head of the humerus and the glenoid
  2. Acromioclavicular joint is made up of the clavicle and that portion of the scapula called the acromion that acts as the roof of the shoulder
• The rotator cuff consists of four tendons that join the scapula with the humerus and allows the arm to be raised and rotated, and, when the arm is raised, keeps the humerus in against the glenoid. The rotator cuff is made up of the tendons of the following muscles - supraspinatus, infraspinatus, teres minor and subscapularis (Figure 2A and 2B)
  1. Supraspinatus - this muscle lies on the posterior (back) upper portion of the scapula and helps to abduct the arm (raise the arm out to the side) as well as keep the head of the humerus against the glenoid
  2. Infraspinatus - this muscle lies on the posterior lower portion of the scapula and acts primarily to rotate the arm outwards
  3. Teres minor - this muscle is attached to the outside edge of the lower part of the back of the scapula and acts with the infraspinatus muscle to rotate the arm outwards
  4. Subscapularis - this muscle lies on the front side of the scapula and acts to rotate the arm inwards

Figure 2a - The muscles whose tendons make up the rotator cuff. A. As seen from in front	Figure 2b - As seen from behind

• Capsule - The capsule of the shoulder is made of a loose fibrous (fiber like) tissue and ligaments. The inside of the capsule is lined with a thin tissue called synovium which secretes a small amount of fluid that keeps the joint lubricated

Pathology

• Dislocation and instability - The glenohumeral joint can dislocate (separate the head of the humerus from the glenoid) or become unstable with frequent or recurrent dislocations. This can occur when falling on an outstretched arm or sudden strong overhead movement such as may occur in certain sports (Figure 3)
• Tendonitis - The tendons about the shoulder can become inflamed and irritated due to repeated minor trauma or fatigue
  1. Impingement syndrome occurs when the tendons of the rotator cuff are pinched under the acromion process of the scapula particularly when the arm is elevated above the head, when the rotator cuff is abraded by a bony spur from the underside of the acromioclavicular joint or from beaking of the anterior edge of the acromion
  2. Rotator cuff tears occur in the younger individual from injury while in the older patient from degeneration of the tissue (Figures 4 and 5a)

Figure 3 - Dislocation of the shoulder with fracture due to injury. Note fragment of bone	Figure 4 - Illustration of a torn rotator cuff

Figure 5a - MRI of a torn rotator cuff. The supraspinatus tendon normally extends over the head of the humerus. Courtesy S. Sadiq, M.D.	Figure 5b - Arthrogram showing dye above the supraspinatus tendon indicating that there is a tear in the rotator club Courtesy S. Sadiq, M.D.

• Fracture (broken bone) - usually this occurs due to fall directly on the shoulder. The bones that may fracture are
  1. Head of the humerus (Figure 6)
  2. Scapula - acromion and/or glenoid
  3. Clavicle - at the shoulder
• Arthritis - The articular cartilage surface of the glenohumeral joint can wear out (or be worn off). This may be the result of trauma, infection or just aging (Figure 7)

Figure 6 - Severe fracture involving the head of the humerus. Courtesy F. Maibauer, M.D.	Figure 7 - Degenerative arthritis of the shoulder with narrowing of the joint. Courtesy F. Maibauer, M.D.

• The shoulder joint may become infected
  1. Adhesive capsulitis leading to a "frozen shoulder"
  2. This is an inflammation of the capsule that may occur with other problems of the shoulder such as bursitis or a rotator cuff tear or
  3. The cause may not be obvious or well understood. The capsule of the shoulder may become inflamed, sometimes, for apparently little cause. This can occur after a minor injury, if the shoulder is kept quiet in a sling following injury to another part of the arm, or associated with a ruptured disk in the neck
• Separation of the acromioclavicular joint - this is caused by a fall on the shoulder in which the outer end of the clavicle is torn away from the acromion process of the scapula
• Labral tear - the labrum may be torn usually as a result of injury to the shoulder. Bits of the labrum may break off causing loose bodies in the joint

History and Examination

• Dislocation and instability
  1. The injury giving rise to the first episode of dislocation of the shoulder is usually fairly severe. With instability there is usually a history of multiple episodes of dislocation after the first severe episode. Less stress is required to dislocate the shoulder once this has happened before. Sometimes the stress is minimal and occurs during normal daily activity
  2. A shoulder dislocation is usually easy to see because the form of the shoulder is obviously not normal
  3. There is pain on movement of the shoulder and if the nerves near the shoulder are compressed there may be numbness or weakness
  4. If the shoulder is unstable, the humerus may slip out of the socket with certain movements of the arm such as raising the arm above the head
• Tendonitis
  1. Impingement syndrome occurs more commonly in individuals who work with their arms above their head. There is aching in the shoulder when raising the arm and there may be pain at night particularly when lying on the shoulder. A sharp pain in the shoulder when trying to reach into a back pocket is common. The impingement syndrome may go on to a tear of the rotator cuff
  2. Tear of the rotator cuff initially causes a vague pain in the shoulder. As the tear increases there is increasing pain and weakness eventually leading to the loss of the ability to abduct the arm (lift the arm away from the body) (Figures 4 and 5A and B)
• Fracture. A fracture of the shoulder is suspected whenever there is pain, swelling and distortion of the shoulder following trauma
• Arthritis of the shoulder is signaled by gradual development of pain in and about the shoulder that is increased with movement of the joint. Crepitus (rough, grinding sensation) may be felt on movement of the joint or there may rough noise. Eventually severe pain develops on movement or touching of the joint
• Infection causes pain, swelling redness of the joint. The pain is made worse by movement, which is usually limited
• Adhesive capsulitis. The prime sign of adhesive capsulitis is pain made worse by any movement whether the patient or the doctor moves the arm. In its initial stage, the pain may be mistaken for a ruptured disk in the neck or even a heart attack. Pain at night is common
• Separation of the acromioclavicular has a history of injury to the shoulder. There may only be some tenderness when touching the joint or there may be an obvious painful bump when there is full separation. Swelling and discoloration of the skin may be seen a few days after the injury
• A tear of the labrum causes a catching or popping sensation with certain movements followed by a persistent ache. The popping sensation is frequently present when raising the arm overhead

Diagnostic Tests

• Because of the complexity of the shoulder, special tests may be necessary
  1. X-ray. An X-ray will demonstrate the bony configuration of the joint or may demonstrate a fracture, dislocation, arthritis, calcification (calcium deposits) or narrowing of the space below the acromion suggestive of impingement or arthritis within the acromioclavicular joint (Figures 3, 6, 7)
  2. Computerized tomography (CT scan). A CT scan is a study that uses an X-ray beam along with a computer to produce a picture of a cross-section view through bone and tissue. A CT scan of the shoulder will better identify bony abnormalities that are not obviously seen by plain x-rays. A CT scan may be necessary to evaluate the size of a cyst (a hole) in the bone, the extent of a fracture or to visualize the surface of a joint
  3. Bone Scan. A very low level radioisotope is injected Into a vein. The material is distributed in the body and after several hours accumulates in certain areas of bone depending on the metabolisrn of the bone. A bone scan is very helpful in the diagnosis of tumors, infection, arthritis and unrecognized fractures
  4. Arthrogram. An arthrogram is an x-ray study in which a radio-opaque dye (a material that shows up on X-ray) is injected into the joint and multiple x-rays are taken to observe the soft tissue defects within the shoulder. Sometimes a CT scan is also taken after the injection to improve the detail of the examination (Figure 5B)
  5. Magnetic resonance imaging (MRI) is a non x-ray study that utilizes radio frequency waves in a strong magnetic field to produce a computer generated picture of the body in three dimensions. It visualizes all of the tissues of the shoulder skin, fat, muscle, tendon:, ligaments, cartilage, bone and within the bone. It is particularly of value in the demonstration of a rotator cuff tear, impingement syndrome, labral tears, and arthritis (Figure 5A)
• Any of these studies may be ordered by the orthopedic surgeon to help make the diagnosis or to differentiate between one or another of the diagnoses

Non-Surgical Therapy

• Resting the shoulder joint with a sling may be useful with arthritis, rotator cuff tear, acromioclavicular joint separation, and the impingement syndrome. Fractures of the upper portion of the humerus may be treated in a sling and allowed to heal unless there are fragments that need to be screwed together
• Anti-inflammatory medication such as aspirin and ibuprofen can be used in most afflictions of the shoulder. Cortisone, which is a stronger anti-inflammatory medication may also be given. Frequently, cortisone may be injected directly into the joint
• Antibiotics are essential in the treatment of a joint infection. It is best to remove some of the infected joint fluid for culture of the bacteria so that the correct antibiotic is used to fight the infection. Sometimes, it is necessary to inject the antibiotic directly into the joint
• Physical therapy is very important in the conservative (non-surgical) therapy of the shoulder. Icing of the painful joint is usually beneficial immediately after an injury while heat is better with more chronic cases. Improving muscle strength is particularly important with the impingement syndrome, shoulder instability, and the lesser rotator cuff tears. A proper therapy program designed to mobilize the shoulder is specially important in cases of adhesive capsulitis

Indications and Contraindications

• In general, surgery is considered when non-surgical therapy fails
  
  1. Dislocation and instability - surgery is considered when repeated dislocation occurs with even light activity, particularly overhead activity
     
  2. Rotator cuff tear repair is considered when pain cannot be relieved by physical therapy, particularly when there is loss of function of the shoulder
     
  3. Insertion of a shoulder prosthesis is indicated in such situations as
     
  • Severe fracture of the humeral head that compromises the blood supply or articular surface
  • Necrosis (death) of the humeral head
  • Dislocation with significant fracture of the articular surface
  • Severe, painful arthritis
• Surgery is contraindicated in the presence of infection or when the general condition of the patient is not satisfactory

Surgical Procedure

• Arthroscopic surgery of the shoulder is the most frequent surgical procedure on the shoulder
  
  1. An arthroscope is a thin instrument that contains a lens at the end that enters the shoulder. The lens focuses on strands of fiber optics that carry the image to a lens at the other end that transfers the image to a small video camera. Light is introduced into the joint through other fiber optics in the scope. The joint is viewed by the orthopedic surgeon on a video monitor. The actual surgical instruments are introduced into the joint through other small incisions called ports
  2. Arthroscopic surgery can be used for partial tears of the rotator cuff, injuries to the soft tissue within the glenohumeral joint such as disruption of the labrum, biceps tendon or ligaments. It can be used in the space beneath the acromion for soft tissue problems, partial tears of the rotator cuff, bursitis, the impingement syndrome including spurs on the under side of the acromioclavicular joint or acromion. Arthroscopy can be used to remove loose bony fragments from the joint and for arthritis of the glenohumeral joint. Arthroscopic repair of recurrent dislocations of the shoulder is being used more frequently
  3. Arthroscopy is usually done with the patient asleep and under general anesthesia
     • The patient lies on his side with the shoulder being operated upon being up. The arm is placed in about 10 pounds of traction
     • Two puncture sites are made, one in the front and the other the back of the shoulder for inserting the arthroscope.
     • Depending on the procedure 1-3 more punctures (about ¼ to ½ inch in length) may be made. The actual surgery is done through these holes while the procedure is seen by the orthopedic surgeon on the monitor screen
     • A sling will be used postoperatively. This is usually an outpatient procedure
  4. Arthroscopy is increasingly being used for surgery of the shoulder such as for recurrent dislocation and instability, labral tears, tears of the rotator cuff and arthritis
  5. Many of the arthroscopic patients will require physical therapy after the procedure
• Open surgery of the shoulder varies with the disease process to be corrected
  1. The surgery for fractures of the shoulder is usually because there are fragments of bone that need to be screwed together
     
  2. The procedure varies depending on the fracture present (Figure 8)
     
  3. A shoulder replacement is carried out primarily for arthritis and occasionally for fractures of the head of the humerus that are in many pieces (Figures 9A - G, and 10)
     
     • A long (6 inch, 15 cm.) incision is made on the front of the shoulder. The muscles are split, the capsule of the joint opened
     • The head of the humerus is excised (removed)
     • A metal ball prosthesis of the correct size is cemented into place
     • In 30-40% of patients the surface of the glenoid (the joint surface of the shoulder blade) is also replaced with a prosthesis
     • The capsule, tendons, and muscles are all repaired and the arm is placed in a sling. However, early motion is desired and the patient will be started on an early exercise program
     • Shoulder replacement for a fracture is a similar procedure, but frequently the landmarks are all disrupted, the muscles and capsule torn. After surgery, the stability of the repair, will determine the time when motion is begun
     • Total shoulder replacement patients are usually in the hospital 3 - 4 days
     • These patients need medication for control of pain control and physical therapy. The duration of the therapy is determined by the surgeon depending on how well the patient progresses
  4. A rotator cuff repair is usually an open procedure
     • An incision 2-4 inches in length is made over the front of the shoulder
     • Any unhealthy cuff tissue is removed and the torn tendons sutured together
     • The tendons of the rotator cuff are reattached with suture using a variety of fixation devices
     • Removal of the end of the clavicle is frequently done with a rotator cuff repair. Also the underside of the acromion may be removed. These procedures are done to increase the space under the acromion and on top of the humeral head so there is more room for motion
     • The arm is usually placed in a sling to decrease the tension on the new sutures. Occasionally the arm is placed in an abduction pillow splint that holds the arm at about a 30 degree angle from the side of the body, a position that does not strain the surgical repair
     • Frequently this will be done as an outpatient with 20-30% of the patients staying overnight for pain control
  5. The surgery for dislocation with instability of the shoulder varies with the direction in which the humerus dislocates relative to the glenoid (Figure 8)
     
     • Usually the dislocation is towards the front of the shoulder and the operation is carried out through an incision in the front of the shoulder
     • The muscles are split, and the anterior shoulder capsule is tightened arid held with sutures or staples
     • The split muscles are sutured
     • The arm is held in a sling to allow healing. The procedure is usually done as an outpatient
       

  

  Figure 8 - Dislocated head of humerus is put back into the glenoid and the fracture fragment from the humeral head is secured with a screw. (See figure 3). Courtesy F. Maibauer, M.D.

  
  

  Figure 9a - The incision line relative to the anatomy of the shoulder.© N. Gordon	Figure 9b - The dislocated humerus is reamed from the humeral head down into the shaft of the humerus.© N. Gordon
  Figure 9c - An air driven saw is used to cut off the articular portion of the head of the humerus, which is held by a special jig devise. © N. Gordon	Figure 9d - An inserter is used to impact the stem prosthesis into the shaft of the humerus. The stem is capped with a metal half ball head that replaces the articular surface. © N. Gordon
  Figure 9e - A depression is reamed into the glenoid with a specially shaped reamer. © N. Gordon	Figure 9f - A special plastic prosthesis is inserted into the reamed glenoid. © N. Gordon
  Figure 9g - The two prostheses are brought together. The overlying muscles and skin are closed with sutures. © N. Gordon	Figure 10 - Shoulder prosthesis inserted because of degenerative arthritis. See figure 7.Courtesy F. Maibauer, M.D.

Complications

• Anesthetic complications are no different than in any other surgical procedure. Breathing and heart problems and death all have to be considered but are unusual
• Infection
• There may be continuing pain
• Excessive bleeding may occur
• Because of the closeness of the nerves to the arm, weakness or paralysis may occur
• Injury to the nearby major artery (axillary) and vein (subclavian) may occur causing clotting of these vessels
• Postoperatively, patients frequently are sore and to regain motion in the shoulder is sometimes difficult. Occasionally patients develop adhesive capsulitis (frozen shoulder) following shoulder surgery
• There may be failure to heal of a fracture or tendon repair
• The prosthesis may loosen
• Wires or pins may move or break
• There may be limited motion of the shoulder

Postoperative Care

• Arthroscopy patients usually have 2 (or 3) puncture sites that are usually dry by the second postoperative day. Normal bathing can usually be resumed at that time. Follow up in the surgeons office is usually around one week after surgery. Generally, no bandage is necessary after the second or third day
• Patients having open surgical procedures frequently have a bandage on for nearly a week at which time the sutures are removed. Showering may be started as directed by the surgeon