Hand Injuries and Disorders Introduction Each of your hands has 27 bones, 15 joints and approximately 20 muscles. There are many common problems that can affect your hands. Hand problems can be caused by certain types of activities. Disease and injury also cause hand problems. When there is something wrong with your hands, you may not be able to do your regular activities. This reference summary explains common hand problems. It also discusses how hand injuries and disorders can be prevented and treated. The Hand and Fingers The hand consists of many bones. The bones are separated by special hinges called joints. Muscles make the bones move on their joints. You can grip objects with your hand because of the muscles in the hand and in the forearm. Each muscle is formed of 2 parts. The fleshy part of the muscle contracts and is the part that creates the movement of the bones. The tendon part of the muscle extends into the hand and attaches to the fingers. The biggest muscles are attached to the bones of the forearms. The muscles taper down and become tendons through the wrist and into the fingers, where they attach to the bones of the fingers. When the fleshy part of the muscle contracts, the tendon is pulled toward the forearm like a cable and the fingers bend. The tendons are held in place by a specialized covering called a sheath. 1
The following sections talk about common hand injuries and disorders, including: Carpal tunnel syndrome. Fractures and dislocations. Osteoarthritis. Tendinitis. Finger disorders. Carpal Tunnel Syndrome The carpal tunnel is a narrow, rigid passageway of ligament and bones at the base of the hand. It houses the median nerve and tendons. Carpal tunnel syndrome happens when the median nerve becomes pressed or squeezed at the wrist. The median nerve runs from the forearm into the palm of the hand. The median nerve controls sensations to the palm side of the thumb. It also controls sensations of all of the fingers except the little finger and half of the ring finger, which is the finger closest to the little finger. It also controls impulses to some small muscles in the hand that allow the fingers and thumb to move. When the median nerve is compressed in the carpal tunnel, it may result in pain, weakness or numbness in the hand and wrist. These symptoms can travel up the arm. Symptoms often start slowly. They may include burning, tingling, itching or numbness in the palm of the hand and the fingers. The feeling may be most noticeable in the thumb and the index and middle fingers. Symptoms often first appear in one or both hands during the night. A person with carpal tunnel syndrome may wake up feeling the need to "shake out" the hand or wrist. As symptoms worsen, people might feel tingling during the day. Decreased grip strength may make it difficult to form a fist, grasp small objects or perform other tasks. Without treatment, the muscles at the base of the thumb may waste away. Some people lose sensation in their hands. 2
Factors that may contribute to carpal tunnel syndrome include: Overactive pituitary gland. Overactive thyroid. Problems in the wrist joint. Rheumatoid arthritis. Trauma, such as sprain or fracture. The pituitary gland makes hormones. These hormones affect growth and the functions of other glands in the body. If your thyroid gland is too active, it makes more thyroid hormones than your body needs. Too much thyroid hormone can make you lose weight, speed up your heart rate and make you sensitive to heat. Rheumatoid arthritis is a form of arthritis that causes pain, swelling, stiffness and loss of function in your joints. It can affect any joint but is common in the wrist and fingers. Other contributing factors include: Development of a cyst or tumor in the canal. Fluid retention during pregnancy or menopause. Repeated use of vibrating hand tools. Work stress. Treatment often involves: Applying cool packs to help reduce swelling. Avoiding activities that may worsen symptoms. Resting the affected hand and wrist for at least 2 weeks. Immobilizing the wrist in a splint to avoid further damage from twisting or bending. Surgery to sever the band of tissue around the wrist to reduce pressure on the median nerve may be recommended for severe cases of carpal tunnel. The name of this surgery is carpal tunnel release. 3
Fractures and Dislocations A fracture is a break in a bone. If the broken bone punctures the skin, it is called an open or compound fracture. Common causes of a fractured bone in the hand are: Car accidents. Falls. Sports injuries. Work-related injuries. Other causes are low bone density and osteoporosis, which cause weakening of the bones. Overuse can cause stress fractures, which are small cracks in the bone. Symptoms of a fracture are: Intense pain. Limited mobility or inability to move a limb. Numbness and tingling. Out-of-place or misshapen limb or joint. Swelling, bruising or bleeding. A fracture needs immediate medical care. You may need to wear a cast or splint. Sometimes you need surgery to put in plates, pins or screws to keep the bone in place. Dislocations are joint injuries that force the ends of your bones out of position. You can dislocate your finger joints. Dislocated joints often are swollen, painful and visibly out of place. You may not be able to move it. Dislocations are most often caused by a fall or a blow. This is usually the result of playing a contact sport. A dislocated joint is an emergency. Treatment might include: Bone repositioning. Medicine. A finger splint. 4
Osteoarthritis Osteoarthritis is the most common form of arthritis. When osteoarthritis affects your hand, it often causes symptoms in your wrist and the joints between your fingers. Osteoarthritis causes pain, swelling and reduced motion in your joints. Bony lumps are common. They are mainly seen on the finger joints. As cartilage in your hand wears down, bone rubs on bone. This damages the bones and causes pain. Cartilage breaks down over time as joints move. The risk for osteoarthritis increases with age. People who have injured a joint in their hand or another area of their body also have an increased risk. There is no cure for osteoarthritis. Treatment focuses on controlling symptoms and may include: Exercise or physical therapy. Medicines. Surgery. Tendinitis Tendinitis means inflammation of a tendon. It causes pain and tenderness near a joint. When it affects the hand, tendinitis most often happens in the wrists. Tendinitis often is caused by injuries and overuse. Sometimes it can be prevented by: Avoiding activities that stress your tendons. Stretching the tendon before an activity. Tendinitis may be treated with rest, ice and medicine to relieve pain and decrease swelling. Other treatments include physical therapy, steroid injections and surgery. Finger Disorders You use your fingers and thumbs to do everything from grasping objects to playing musical instruments to typing on a keyboard. When there is something wrong with them, it can make life difficult. Common finger disorders include: Dupuytren s contracture. Trigger finger. 5
Dupuytren s contracture is a thickening of the tough tissue just below the skin of your palm. It causes the fingers to stiffen. Over time, the fingers may curl and bend. It may be difficult to straighten your hand. Dupuytren s contracture also causes small, tender lumps to form in the palm. The exact cause of Dupuytren's contracture is not known. It often runs in families. It is not caused by an injury or heavy hand use. Mild cases of Dupuytren s contracture may not need treatment. If treatment is needed, it may include: Needling. Enzyme injections. Surgery. The goal of these treatments is to loosen or remove the tough tissue causing the fingers to stiffen and curl. Needling uses a needle inserted into the skin to break the tissue that causes a finger to curl. This treatment may need to be repeated. Enzyme injections can loosen or weaken the tough tissue causing Dupuytren s contracture. Your health care provider may then attempt to move the hand in ways to break the tissue. Trigger finger is a common condition that causes pain and interferes with normal use of the hand. Trigger finger happens when the tendon that controls the movements of your fingers and thumb becomes irritated. This often happens as it slides through the snug tendon sheath tunnel it passes through. When the tendon and its covering become inflamed and swell, they are unable to move in the sheath and the finger remains bent. The tendon may release and cause a popping feeling. The finger will suddenly shoot straight out as the tendon slips through the tight area.trigger finger is usually the result of repetitive movements. 6
Your health care provider may recommend the following treatments for trigger finger: Avoiding repetitive motion to help lessen symptoms. Medicines to reduce swelling. Resting the affected finger. Steroid injections around the tendon. Surgery or another procedure. Summary Each of your hands has 27 bones, 15 joints and approximately 20 muscles. There are many common problems that can affect your hands. Hand problems can be caused by certain types of activities. Disease and injury also cause hand problems. When there is something wrong with your hands, you may not be able to do your regular activities. This reference summary focused on common hand injuries and disorders, including: Carpal tunnel syndrome. Fractures and dislocations. Osteoarthritis. Tendinitis. Finger disorders. If you have symptoms of a hand injury or disorder, contact your health care provider. Only your health care provider can tell what is causing your symptoms. Treatment for hand injuries and disorders depends on the type of disorder or injury you have. 7