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:
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:
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.