Bone, joint, and muscle disorders

Bones and muscles give the body its strength and shape; with joints, they also allow the body to move. Disorders affecting them are usually treated by an orthopedic specialist, though other specialties, such as neurology for neuromuscular disorders, rheumatology for joints, physiotherapy to aid recovery, and alternative treatments, such as osteopathy, may also be used.

Broken bones are the most frequent condition treated by an orthopedic surgeon. The most common types include (A) a simple or closed fracture; (B) a compound or open fracture, in which the broken bone punctures the skin; (C) a comminuted fracture, in which the bone at the site of the break is in several fragments; and (D) a greenstick fracture, common in children, in which the bone bends and breaks on one side only. Broken limb bones are usually set and kept in a plaster of Paris cast while they heal.

Fractures and dislocations

The commonest bone, joint, and muscle disorders are fractures, dislocations, and sprains. In most cases, they are relatively easy to treat, although complications can occur.

Dislocation occurs when the bones at a joint are separated or violently misaligned. Muscles, ligaments, and tendons can be stretched or torn in a dislocation, as well as in injuries such as sprains, where dislocation does not occur.

In all fractures and dislocations, the first treatment is to reset (“reduce”) the broken bone or the misaligned joint so that all elements are correctly repositioned. This can be checked by means of X rays. The affected parts are then immobilized while bones, tendons, and ligaments mend. Fractures are usually immobilized by splints, bandages, or plaster of Paris casts. Traction a way of gently keeping an affected limb extended, using a balanced system of pulleys and weights may also help to maintain the straightness of a reset bone. In certain cases, internal support is provided by fixing metal pins or plates to the bone. This has the advantage of allowing muscles to be used again as soon as possible, which is important for their healing. Sometimes the pins or plates are removed again at a later date. Some fractures are slow to heal and may be helped by the application of mild electric current to the fractured site. Ultrasound may also be used to speed healing of traumatic damage. It is not known why these last two treatments are effective, however.

Rheumatoid arthritis is a degenerative disorder of the joints often accompanied by inflammation and swelling.

Other bone disorders

Bone diseases are uncommon, because bone tissue is well protected from primary infections and because degenerative and deficiency disorders are rare in Western countries.

If bone becomes infected, the most likely disease is osteomyelitis, a bacterial infection of the actual substance of the bone. The infection usually enters through an open fracture or through the bloodstream. The disease most commonly attacks the ends of the long bones of the arm or leg, and is especially likely to affect children. Prompt treatment with antibiotics is almost always effective. Tuberculosis of the bone is a special form of osteomyelitis. It can affect any bone tissue but often involves the spine.

In older people, and especially in women, the bones become more brittle in a disorder called osteoporosis. Hormonal factors causing bone calcium levels to be reduced or some deficiency in dietary intake may contribute to the condition, and hormone, vitamin, or calcium supplements and exercise may be prescribed in treatment.

A lack of vitamin D, normally obtained in the diet or made by the skin in response to sunlight, disrupts calcium and phosphorus metabolism and causes the bone disease called rickets in children or osteomalacia in adults. It is now rare in developed countries. Treatment consists of adding vitamin D to the diet.

Muscular dystrophy involves progressive degeneration of the muscles. The Duchenne type (A) affects the pelvis first, then the trunk, shoulders, and limbs. The facio-scapulo-humeral type (B) progresses from the face and shoulders to the trunk and limbs. The limb-girdle type (C) affects the muscles of the hip and shoulder first.

Disorders of the joints and muscles

Clubfoot, muscular dystrophy, and congenital hip dislocation are all disorders present at birth. Clubfoot, caused by muscular anomalies, can be treated by splinting, physiotherapy or, in some cases, surgery to lengthen tendons that are too short. Muscular dystrophies form a group of inherited, progressive diseases that inhibit muscle function. They affect men more often than women. Congenitally dislocated hips can be treated with splints if diagnosed early enough.
Arthritis is the most common joint disorder. The term meaning joint inflammation—is applied to rheumatoid arthritis, osteoarthritis, and infective arthritis.

Rheumatoid arthritis is a chronic inflammation of the joints, especially the small ones in the hands and feet. The cause is unknown but may be due to an autoimmune reaction or to an unidentified infection. Symptomatic relief may be achieved with heat treatment, but usually anti-inflammatory drugs such as aspirin are required. Steroids may be necessary in very severe cases. If the disease progresses to permanent joint destruction, the damaged bone ends can be removed and replaced by artificial joints, restoring movements to an otherwise uselessly stiff or deformed hand. Physiotherapy works well in less severe cases.

Osteoarthritis is a degenerative disorder that tends to affect the elderly, usually in the larger joints, such as those of the hip and spine; it may also affect younger patients after trauma.
Treatment for all forms of arthritis involves the use of drugs such as aspirin or nonsteroidal anti-inflammatory agents, which help to relieve pain and reduce inflammation. In severe cases, surgery may be necessary for example, to replace an osteoarthritic hip.

Backache is probably the single most common source of discomfort in Western countries. Causes range from minor muscle or ligament strain to serious problems, such as a slipped disk (properly known as a herniated or prolapsed intervertebral disk) or secondary deposits of cancer. Serious disorders may need surgical correction to prevent permanent damage to the spinal cord and nerves. Less dangerous causes of backache can be relieved by relaxation, ultrasound treatment, acupuncture, or osteopathy (spinal manipulation). Since a significant component of pain is psychological, any therapy that concentrates on providing mental relaxation is also likely to relieve symptoms.

Artificial limbs

Some amputated limbs can be repaired using microsurgical techniques to re-implant severed muscles, ligaments, blood vessels, and nerves. In other cases, it is necessary to replace a limb with an artificial one (prosthesis). The simplest (such as the traditional wooden leg) provide balance but little else. More sophisticated prostheses aim to replace the limb’s function, and some now available have all the appearance of normal flesh. Furthermore, recent advances in microelectronics make it possible to build artificial hands that respond to the nerve impulses and muscle contractions of the remaining forearm, facilitating movements such as grasping.