Common conditions

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 Carpal tunnel syndrome is a condition affecting one of the main nerves  in the wrist area. The carpal tunnel is a space created by the natural  arch of the wrist bones. A thick band called the transverse carpal  ligament creates a roof to the tunnel. This means that the size of the  tunnel cannot change, as the bones and ligament act like solid walls.  Nine tendons that bend the fingers and thumb and the median nerve pass  through the tunnel. The median nerve provides feeling (sensation) to the  skin of the thumb, index and middle fingers, as well as half the ring  finger. The nerve also provides the communication line to the muscles at  the base of the thumb (thenar muscles). 

 A wrist fracture is a medical term for a broken wrist. The wrist is made  up of eight small bones which connect with the two long forearm bones  called the radius and ulna. Although a broken wrist can happen in any of  these 10 bones, by far the most common bone to break is the radius.  

Some  wrist fractures are stable. “Non-displaced” breaks, in which the bones  do not move out of place initially, can be stable. Some “displaced”  breaks (which need to be put back into the right place, called  “reduction” or “setting”) also can be stable enough to treat in a cast  or splint. Other fractures are unstable. In unstable fractures, even if  the bones are put back into position and a cast is placed, the bone  pieces tend to move or shift into a bad position before they solidly  heal. This can make the wrist appear crooked.

 Movement in the hand and fingers is controlled by a system of muscles  and tendons located in the forearm, wrist and hand. Tendons  connect muscles to bone. When a muscle contracts, or tightens, the  muscles power the tendons to move our bones. The ability to bend our  fingers to make a fist is controlled by the flexor tendon. Most commonly, a flexor tendon injury results from lacerations (cuts). A  laceration to the forearm, hand or wrist can result in injury to the  flexor tendons. When a flexor tendon injury happens there can be  inability to bend the fingers, thumb or wrist. Even small lacerations  can result in significant problems with movement if they occur in an  important location. Not all tendon injuries are due to lacerations. In  some cases, the flexor tendon injury can occur if the tendon end pulls  away from bone, if the tendon ruptures due to wear, or if the  tendon-muscle interface separates. In the hand, wrist and forearm  lacerations are the most common cause of flexor tendon injury. However,  if you lose motion in a part of your arm, then tendon injury, even  without a laceration, should be considered a possible cause.  

 A trigger finger is a very common and treatable problem. It can occur in  both fingers and the thumbs, which have tendons that help them to bend.  The flexor tendons that bend the fingers have a lining on the outside.  This lining is called tenosynovium. The tendon and lining are covered by  a series of thick, soft tissue called pulleys. The tendon and its  lining are designed to glide through the pulleys without friction. The  pulleys are similar to how a line is held on a fishing rod.

A  trigger finger, sometimes referred to as a trigger thumb or stenosing  tenosynovitis, can occur if one of three things happen: 1. The tendon  enlarges (does not fit through pulley well); 2. The lining increases in  thickness (does not fit through pulley well); 3. the pulley becomes  thicker (the opening for the tendon gets smaller). The finger tendon and  pulley system is designed to have the exact right sizes of each  structure. The change in size of any of the important finger structures  can cause problems. If the tendon becomes tight within the pulley, the  lining gets squeezed and reacts with thickening. The bigger lining then  produces more fluid. And the higher volume of fluid increases pressure.  The undersurface of the pulley can also change and thicken. This thicker  pulley causes friction on the moving tendon. This makes it difficult  for the tendon to move back and forth.

 Lateral epicondylitis, commonly known as “tennis elbow,” is a painful  condition involving the tendons that attach to the bone on the outside  (lateral) part of the elbow. Tendons transmit  a muscle’s force to the bone. The muscle involved in this condition,  the extensor carpi radialis brevis, helps to straighten and stabilize  the wrist (Figure 1).

With lateral epicondylitis, there is  degeneration of the tendon’s attachment, weakening the anchor site and  placing greater stress on the area. This can lead to pain associated  with activities in which this muscle is active, such as lifting,  gripping and/or grasping. Sports such as tennis are commonly associated  with this, but the problem can occur with many different activities. 

 The rotator cuff is the group of four muscles and tendons that surround  the shoulder joint. The four muscles are called the supraspinatus,  infraspinatus, subscapularis, and teres minor. The most common tendon to  have a problem is the supraspinatus. On top of the rotator cuff is the  deltoid muscle. The bones at the shoulder include the humerus, scapula  (shoulder blade), and clavicle (collar bone). The rotator cuff muscles  start on the shoulder blade and attach around the front, top, and back  of the humerus. They help to elevate the arm away from the body in  forward, side, and backward motions. They also turn the arm in or out to  rotate the shoulder. These muscles and tendons provide strength and  stability to the shoulder joint.

Above the rotator cuff there is a  bursa - a sack of tissue that cushions and protects two surfaces so  that they do not rub directly against each other when they move. The  rotator cuff bursa protects close contact between bones around the  shoulder. When the rotator cuff is injured or damaged, it can  lead to inflammation of the bursa, called bursitis. Bursitis can cause  pain and loss of motion. 

Cubital Tunnel Syndrome is a condition that involves pressure or  stretching of the ulnar nerve (also known as the “funny bone” nerve),  which can cause numbness or tingling in the ring and small fingers, pain  in the forearm, and/or weakness in the hand. The ulnar nerve runs in a groove on the inner side of the elbow. 

There are a few causes of this ulnar nerve problem. These include:

• Pressure: The nerve has little padding over it. Direct  pressure (like leaning the arm on an arm rest) can press the nerve,  causing the arm and hand — especially the ring and small fingers — to  “fall asleep.” 
• Stretching: Keeping the elbow bent for a long time can stretch the nerve behind the elbow. This can happen during sleep.
• Anatomy:  Sometimes, the ulnar nerve does not stay in its place and snaps back  and forth over a bony bump as the elbow is moved. Repeated snapping can  irritate the nerve. Sometimes, the soft tissues over the nerve become  thicker or there is an “extra” muscle over the nerve that can keep it  from working correctly.

Nerves are the body’s “telephone wiring” system that carries messages between  the brain and the rest of the body. Some nerves carry messages from the  brain to muscles to make the body move. Other nerves carry messages  about pain, pressure, or temperature from the body to the brain. Many  small fibers are bundled inside each nerve to carry the messages. There  is an outer layer that insulates and protects the nerves.  Sometimes, nerves can be damaged.

 Nerves can be damaged by too much pressure, by stretching, or by a cut. Carpal Tunnel Syndrome is an example of a problem that arises from too much pressure on the  median nerve in the hand. Carpal tunnel syndrome can injure the median  nerve slowly over time or, in the case of trauma to the area, it can  occur much more quickly.

A cut to the nerve can cause it to no  longer transmit signals, because the signal cannot jump through a gap in  the nerve. Stretch injuries to the nerve can range from mild, temporary  nerve injury to a more severe, permanent nerve injury. The extent of  the injury depends on the amount of stretch. 

Hand bones are called metacarpals. The finger bones are called phalanges. The  metacarpophalangeal joint (MCP joint), or knuckle, is where the finger  bones meet the hand bones. At the MCP joint, the fingers can move in  multiple directions. They can bend, straighten, spread apart and move  together. MCP joints are important for both pinching and gripping.

MCP  joint arthritis is most common in the thumb and index fingers due to  the stress of pinching. The different joints of the hand are shown in  Figure 1.

Arthritis means joint inflammation and is a word that  is often used to describe pain or a problem at a joint. Arthritis occurs  when there is a loss of cartilage. Cartilage is the layer of tissue on  the end of a bone.

The MCP joint can be affected by arthritis from many different causes. They include but are not limited to:

• Osteoarthritis which is routine wear and tear
• After an injury, which could include a broken bone where the crack extends into the joint
• Certain medical conditions (rheumatoid arthritis, gout and pseudogout, psoriasis, etc.) 

 A cortisone shot can be used to treat some problems in the arm and hand. These can include trigger fingers, tendonitis, carpal tunnel syndrome, arthritis, tennis elbow, and rotator cuff tendonitis. These injections usually contain a numbing medicine.

Cortisone  is a steroid normally produced by your body, and it is a powerful  anti-inflammatory. Corticosteroids tend to shrink, thin and slow things  down. These steroids are different from anabolic steroids, which have  been abused by athletes to build muscle and enhance performance.

 The cortisone shot should take effect within a few days, and the  benefits can last for many weeks; however, results are not the same for  everyone or every problem. For some conditions, one injection solves the  problem. For others, several injections may be required. There is no  set rule as to how many injections a person can get. Your doctor might  limit the number of injections because repeated cortisone can damage  tendons and/or cartilage.

 The tendon is the strong cord at either end of a muscle that is attached to bone. Tendons,  combined with their muscles, allow you to move your joints.

In  the forearm and hand there are over forty different muscles. Many of  these muscles perform overlapping functions.  After an injury, some of  your muscles may not move correctly. A tendon transfer is a surgery that  moves a working muscle and tendon to replace a non-working muscle and  tendon.

For example, after a broken wrist, the tendon to the  thumb (EPL tendon) that allows you to make a “thumbs-up” can break.   Often, the two ends of the tendon are very damaged and cannot be sewn  back together.  There are two tendons that extend the index finger, and  this finger can function adequately with just one. A hand surgeon can  transfer one of the index finger tendons to the thumb to allow you to  give a “thumbs-up” again.

Wrist arthroscopy is a wrist surgery that allows a doctor to see the  inside of a joint. It is performed after a patient sustains an injury  such as a fall or a twisting of the wrist and is experiencing pain,  clicks or swelling. These symptoms may mean there is an internal problem  of the wrist. Arthroscopy is often the best way of directly looking at  the injury and repairing it. The procedure can be used to help align  fractures of the wrist, remove some ganglions of the wrist, wash out infection, or remove excess joint lining associated with inflammation from conditions like rheumatoid arthritis.

In  the last five years, the wrist has become the third most  common joint to undergo arthroscopy, after the knee and shoulder.  Because the cuts used with this procedure are smaller and disrupt less  soft tissue than typical surgery, pain, swelling and stiffness are  minimal, and recovery is often faster.