Shoulder Joint Replacement

When nonsurgical treatments fail to improve pain and function, it may be time to talk to your surgeon about shoulder replacement surgery. Shoulder replacements are less common than knee replacements, but they are just as effective for alleviating joint pain. Shoulder replacement surgery can help restore motion and strength, getting you back into your everyday activities.

Anatomy and Description

The shoulder is composed of the humerus (upper arm bone), scapula (shoulder blade), and clavicle (collarbone).  The shoulder is a ball and socket joint, with the head of the humerus fitting into a shallow socket on the shoulder blade (glenoid).  The articulating surfaces of these bones are covered in cartilage; a smooth material that envelopes the bones and facilitates gliding movement.  A synovial membrane coats the remaining surfaces of the joint.  When the joint is healthy, the synovial membrane produces a fluid that serves to lubricate the cartilage and reduce friction with movement.  Shoulder stability is provided by muscles and ligaments which surround the joint.  The shoulder joint has the greatest range of motion of all the joints in the body as a result of these structures.

In a shoulder replacement surgery, damaged parts (the ball, socket, or both) are removed and replaced by a titanium prosthesis. 


Causes of Shoulder Pain and Disability

Osteoarthritis – the loss of cartilage from wear and tear, typically age-related. Can be accelerated by overuse such as heavy weightlifting or repetitive overhead movements

Rheumatoid arthritis – occurs when the synovial membrane that lines the joint is affected by an autoimmune disease that causes inflammation and eventually joint destruction

Post traumatic arthritis – caused by fractures of the upper humerus that damage the healthy cartilage or change the alignment of the joint, resulting in premature wear of the joint over time

Rotator cuff tear arthritis – a large, untreated rotator cuff tear causes abnormal contact between the head of the humerus and the acromion (extension of the shoulder blade covering the head), and will eventually lead to damage of the cartilage, inducing arthritis

Avascular necrosis– takes place when the blood supply to the bones is disrupted. Eventually the bone cells die, causing loss of cartilage when the supporting bone is lost

Severe fractures – when the ball of the humerus is fractured, it can be difficult to piece back together and may not heal.  Shoulder replacement surgery is an excellent treatment option if the fracture cannot be repaired


Types of Shoulder Replacement

Total Shoulder Replacement  – replacement procedure that restores both the ball and socket.  The ball is attached to the upper humerus with a stem that is placed within the hollow center of the bone (canal). The socket is attached with several pegs that fit into small holes created in the glenoid (socket) bone.  Requires a healthy rotator cuff for proper function and longevity.

Total Shoulder Resurfacing – rather than remove the entire head for replacement, only the joint surface is replaced.  This is essentially a cap that is placed over the diseased humeral head.  There is no stem placed down into the canal of the upper humerus.  The socket is also replaced in this procedure.  Also requires a healthy rotator cuff for proper function and longevity.

Shoulder Hemiarthroplasty (partial replacement) – in select cases, the glenoid surface does not need to be restored; only the ball is replaced with a stemmed or resurfacing component.  This procedure can be performed for treatment of a fracture or for arthritis.  Hemiarthroplasty does not require a healthy rotator cuff to function properly. 

Reverse Total Shoulder Replacement – this type of shoulder replacement is commonly performed when the rotator cuff has been chronically torn and is no longer functional.  Reverse replacement can also be performed for severe fractures where long term rotator cuff function might be compromised.  In this procedure, a metal ball is secured to the glenoid (socket), and a stem is placed within the humeral canal with a socket where the ball is normally located (hence the term reverse replacement).  This reversal of the anatomy changes the way the ball and socket fit together and the way the muscles in the shoulder work to move the arm; replacing the function of the damaged rotator cuff. 


Recovery from Shoulder Replacement Surgery

Typically, a sling will be used for several weeks after surgery.  Movement of the arm may be restricted for a period of time while the bones and muscles heal.  Physical therapy will be employed to restore range of motion, decrease pain and swelling, and improve strength.  The goal of physical therapy is to return the patient to their daily activities, including work and leisure activities. 

Shoulder Dislocation

The shoulder is the most mobile joint in the body, making it the easiest to dislocate. In a shoulder dislocation, the ball is separated from the socket. The ball can be displaced in multiple directions. Dislocating toward the front (anterior)is the most common dislocation, followed by the back (posterior), and then underneath the socket (inferior). Dislocations can be accompanied by fractures, ligament tears, rotator cuff tears, and occasionally nerve damage.

Symptoms of Shoulder Dislocation

  • Severe pain
  • Inability to move or raise arm
  • Swelling
  • Numbness
  • Obvious deformity of the shoulder

Treatment of Shoulder Dislocation

Treatment for shoulder dislocation is typically carried out in an emergency room. With appropriate sedation or pain medication, the physician will manipulate the ball back into the socket. This procedure is called a closed reduction. After the reduction, X-rays will be performed to ensure adequate restoration of the shoulder joint relationship and to evaluate for any fractures. You’ll then be placed in a sling to let the shoulder rest for several days.  After an appropriate rest period; rehabilitation can be performed to restore shoulder mobility and strength.  Adequate strength of the rotator cuff is paramount to preventing repeated dislocations.  If ligaments or tendons are torn, repeated dislocations can occur; possibly requiring surgery to correct the problem.  Surgery might also be necessary if fractures occur at the time of dislocation.  Generally, nerve damage that occurs as a result of shoulder dislocation resolves on its own but may take several months.

Growth Plate Fractures

What are growth plate fractures?

Children’s bones are uniquely susceptible to an injury called a growth plate fracture. A single traumatic event like a fall or a car accident can cause a growth plate fracture. Overuse and chronic stress can also create fractures in the growth plate. Near the end of long bones are areas of developing cartilage called epiphyseal plates or growth plates; this is where the growth of a bone occurs. Once a child has become full-grown the growth plates will harden and solidify into bone. Because growth plates are the last portion of the bone to harden they are more at risk for fractures. Children’s bones heal much quicker than adult’s. Thus, if a child is injured they should see a doctor as soon as possible (see an orthopaedic specialist within 5-7 days of injury). Proper treatment is needed before the bone starts to heal, especially if the injury is out of alignment and needs to be manipulated. Since children’s bones heal much faster, their time in a cast will not need to be as long as an adult’s. While growth plate fractures may be common, serious problems like deformities are rare. If the damage to the area is severe it could disrupt the normal growth pattern of the bone causing a deformity. Some deformities include curved or disproportionate length of limbs. Talk with your orthopedic specialist about the type of injury to the growth plate, possible treatment options, and follow up assessments to monitor the outcome of the injury long term.


Symptoms, Signs, Tests, and Risk

If a child is unable to put pressure on a limb or move the limb and the pain is persistent, they should see a physician. Visible deformity is another definite indicator that the child needs to see a physician as quickly as possible. When the bone is broken, the area near the joint may be warm, tender, swollen, and may even appear to be bent in contrast to the uninjured side. Doctors will examine and most likely use x-rays to diagnose the growth plate fracture. There are cases where the doctor may need to use other tests such as ultrasound, magnetic resonance imaging (MRI), or a computed tomography (CT) scan. Those who are at a greater risk of growth plate fractures are as follows:

  • All children who are still growing
  • Growth plate fractures occur twice as often in boys as in girls
  • One third of all growth plate fractures injuries occur in competitive sports
  • Recreational activities such as skiing, biking, and skateboarding account for a large percentage of growth plate fracture as well

Classifications and Treatments

Classification of a growth plate fracture depends on extent of damage to the growth plate itself. There are several different systems that have been developed to classify growth plate fractures. The Salter-Harris system is possibly the most popular classification system used.

Type I: The fracture occurs all the way through the bone by the growth plate, completely separating the end of the bone from the shaft.

Type II: The fracture occurs through the shaft of the bone as well as part of the bone by the growth plate.

Type III: The fracture occurs across the growth plate and an end piece breaks off.

Type IV: The fracture occurs all the way through the end of the bone, growth plate, and shaft of the bone.

Type V: The fracture occurs because a compression force causes a crush injury to the growth plate (rare).

The classification of the fracture also helps determine the type of treatment the break will receive. Other factors such as health and age of the patient, related injuries, and the severity of the dislodgement of the broken ends of the bone may also affect the type of treatment fracture will be given.

Type I: Fractures can cause disrupted bone growth. Surgical treatment might be needed, but many times these types of breaks can be treated with cast immobilization. When surgery is needed, most often internal fixation (pins or screws) is used to ensure the bone holds together and correct alignment is sustained.

Type II: This is the most common type of growth plate fracture and typically heals well. Cast immobilization is most often used, but in some cases surgery may necessary.

Type III: This is more common in older children. This is because as the child gets closer to being fully grown, the growth plate hardens. Since the growth plate has begun to harden in older children the fracture will not continue through the bone but angle down and break off the end of the bone. Internal fixation is the surgery treatment for this type of fracture to make sure appropriate alignment is maintained for both the joint surface and growth plate.

Type IV: Treated by surgery and internal fixation, but commonly causes bone growth to stop

Type V: May require surgery, but is often repaired with cast immobilization. Growth disturbances are almost always present with these types of fractures.

No matter which type of growth plate fracture has occurred, they should always be monitored carefully to ensure appropriate healing and bone alignment. For at least one year, follow up with the doctor should be carried out. Check with your doctor to see if the child should be followed up for an extended period. This can vary depending on the severity and location of the fracture.

Frozen Shoulder

Frozen shoulder is a common condition that results in significant pain coupled with an inability to move the shoulder. The medical term for frozen shoulder is adhesive capsulitis. Women are typically affected more often than men, and it is generally seen between the ages of 40 and 60. 

Anatomy and Description

Your shoulder is a joint made up of three bones. These include the humerus (upper arm bone), scapula (shoulder blade) and the clavicle (collar bone). All three of these bones come together to create a ball and socket joint. The shoulder capsule is the tough connective tissue that surrounds the joint where the humerus fits into a shallow socket in the shoulder blade called the glenoid. The capsule surrounds the ball and socket, functioning to maintain shoulder stability and supply lubricating synovial fluid to the joint surfaces.  When a frozen shoulder develops, the capsule becomes thickened and inflamed, and eventually becomes so tight that it restricts motion.  The inflammation in the capsule makes daily activities very painful. 

One of the first signs of a frozen shoulder is the inability to move your shoulder actively (using your own muscles) or passively (with the help of an outside force). The shoulder becomes tight, the shoulder capsule thickens, and stiff bands of tissue called adhesions develop to limit joint motion.  A typical frozen shoulder goes through three phases. In phase 1, known as the freezing phase, pain gradually increases and the shoulder range of motion decreases. The capsule thickens and adhesions form, limiting motion. The freezing phase is typically the most painful, and the time when most patients will seek a doctor’s care. This phase can last between 6 weeks and 9 months. The second phase is known as the frozen phase. In this phase, the pain is generally decreased, however the motion does not improve. Daily activities are difficult due to loss of motion. The frozen phase typically lasts 4 to 6 months but can persist for years. In the final phase, known as the thawing phase, the motion gradually improves, and function and strength return as well. The thawing phase will typically last between six months and two years.


Causes

The cause of frozen shoulder is not completely known; however, there are several known  factors that may increase your risk of developing a frozen shoulder. These factors include hypothyroidism, hyperthyroidism, Parkinson’s disease, cardiac disease, diabetes, and immobilization after injury. Frozen shoulder affects somewhere between 10% to 20% of diabetic individuals, but the reason is still unknown. After a fracture or surgical procedure, immobilization can lead to frozen shoulder. Programs that encourage patients to gently move the shoulder after surgery or fracture can often be employed to prevent frozen shoulder. 


Symptoms

  • Dull aching pain in the shoulder
  • Pain with attempted movement of the arm
  • Pain typically felt above the outer shoulder area or the upper arm

Treatment

Typically, frozen shoulder will resolve without treatment, however this may take up to three years.  The goals of treatment for frozen shoulder are to restore motion and decrease pain as quickly as possible. First, a medical history and physical exam will be performed. The hallmark physical exam finding is loss of both active and passive range of motion. X-rays can be taken to rule out other causes of shoulder stiffness such as arthritis. Magnetic resonance imaging (MRI) may be used to rule out other disorders such as rotator cuff tears.   Treatment selected can be  surgical or non-surgical, based on the effectiveness of previous treatment and severity of illness.

Nonsurgical treatment includes nonsteroidal anti-inflammatory medications, steroid injections, or physical therapy. Ibuprofen and aspirin are nonsteroidal anti-inflammatory medications that can reduce pain and swelling. A strong anti-inflammatory medication known as corticosteroid can be injected directly into the shoulder joint. These treatments are typically combined with physical therapy to stretch the contracted capsule and release adhesions.

Surgical Treatment can be used if nonsurgical treatment does not improve shoulder motion or decrease pain. The main goal in surgical treatment for frozen shoulder is to stretch and release the contracted joint capsule and adhesions. The two most common surgical treatments include manipulation under anesthesia and lysis of adhesions. During a manipulation under anesthesia, the surgeon slowly and deliberately moves the shoulder to stretch and split scar tissue and capsule while you are under the care of an anesthesiologist so minimal pain is felt. In the lysis of adhesions procedure, a small camera is inserted into the shoulder with small instruments to release the scar tissue and capsule. After motion is restored with surgical treatment, physical therapy is very important to maintain the motion achieved. The recovery from these procedures can last between six weeks and three months.

Rotator Cuff Tears

Rotator cuff tears are very common among adults. A torn rotator cuff can cause your shoulder to become painful and weak, making daily activities like getting dressed or brushing your hair a daunting task.

Anatomy

The shoulder is composed of your humerus (upper arm bone), scapula (shoulder blade), and clavicle (collarbone). It is a ball and socket joint formed by a ball on top of the humerus fitting into a shallow socket located in your shoulder blade known as the glenoid. The ball and socket are held together by unit of four muscles that surround and attach to the ball.  The junction between the muscle and bone occurs through a tendon, a white fibrous extension of the muscle that is optimized for attachment to bone. This muscle and tendon unit is known as the rotator cuff.  The primary functions of the rotator cuff are to stabilize the ball and socket and to assist with movement of the arm. A bony extension of the shoulder blade forms a type of “roof” over the shoulder joint.  This bone is called the aromion. A bursa sac aids in lubricating the rotator cuff and minimizes friction between the tendons and the bone. If the rotator cuff becomes injured, the bursa can become swollen and inflamed causing pain.  This condition, known as bursitis, is generally the earliest phase in development of a rotator cuff tear.  As the condition progresses, friction between the rotator cuff tendon and the acromion develops and eventually damages the tendon, this process is known as impingement. Bone spurs on the undersurface of the acromion can accelerate the process of rotator cuff degeneration and tearing. 


Causes and Symptoms

There are two types of rotator cuff tears:

Acute Rotator Cuff Tears occur as a result of a traumatic injury such as falling onto an outstretched arm or lifting a heavy object too quickly.  These tears are generally felt as a ripping or tearing sensation and cause immediate pain and disability.   Shoulder dislocations can lead to acute tears as well.

Degenarative (or Chronic) Rotator Cuff Tears occur over time and with age. The tendons slowly degenerate, typically as a result of impingement or bone spurs.  As opposed to acute rotator cuff tears, motion is often preserved with degenerative tears and pain and weakness are common presenting symptoms.