What are Bone Disorders?
Bone is a living tissue with its own blood supply. It contains calcium and phosphors, which combine to make it hard and rigid, while its multi-layered structure makes it strong. Generally speaking, bone is affected by the same kinds of disorder that affect other tissues.
What type of bone disorders are there?
> Genetic (inherited): These conditions include achondroplasia, or dwarfism, a rare bone growth disorder usually affecting the long bones of the limbs and likely to cause short stature.
The other principal genetic disorder is osteogenesis imperfecta, which is characterized by abnormally brittle bones due to an inherited disorder in the connective tissue that forms the basic structure of the bones. The brittleness of the bone makes them liable to fracture.
> Nutritional disorders: Calcium is essential for the formation of strong healthy bones. In addition, Vitamin D is needed for the absorption of calcium from the intestines into the blood and thence for its incorporation into bone.
A lack of calcium and vitamin D may cause bone deformity. In children, this is known as rickets and particularly affects the legs and spine. In adults, it is called osteomalacia and causes pain in the bones, especially of the neck, legs, hips and ribs and make them liable to fracture. Both conditions are rare in developed countries, though they can occur as a complication of a digestive disorder which hinders food absorption.
> Bone Tumors: Several kinds of tumor, both benign and malignant can affect the bones. Primarily, bone cancer is rare, while secondary bone cancer, which has spread from cancer elsewhere in the body, is more common, especially later in life.
> Hormonal Disorders: If the pituitary gland produces too much growth hormone before a child reaches puberty, this causes an overgrowth of bones, leading to excessive structure (giantism). Too much parathyroid hormone may cause erosion of the bones.
Another possible result of hormonal imbalance is osteoporosis, which cases bone to be brittle. Thinning of the bone is a natural part of ageing, but severe osteoporosis is more common in women than in men.
This is partly because women have about 30% less bone mass than men, but it is also because the hormone estrogen seems to play a role in female bone metabolism and therefore the reduction of estrogen levels following the menopause accelerated the rate of bone mass loss.
> Auto immune disorders: The most common auto immune disorder (in which the body’s immune system attacks its own tissues) affecting the bones is rheumatoid arthritis. This is a condition in which the joints become inflamed and the ends of the bones may also become eroded, resulting in an increase in pain. Rheumatoid arthritis usually begins in early adulthood or middle age.
> Degenerative disorders: These are more common in old age. One such condition, known as osteoarthritis, causes the cartilage ends of the bones to become worn and to waste away, leading to stiffness, pain and, in sever cases loss of function of that joint.
The joints most commonly affecter are those in the neck, the lower back, knees and hips. The condition mostly occurs after the age of 60 and affects three times as many women as men.
However, osteoarthritis is a joint disorder rather than a bone disorder. In addition to wear and inflammation of the cartilage surfaces inside the joints, the ends of the bones may overgrow to form spikes (osteophytes). These spikes may further restrict joint movement. Repeated injury to a joint increase the risk of developing this condition.
> Paget’s Disease: This disease, which affects people over the age of 50 years, is a disorder in which the bones normal maintenance system is disrupted and new bone is produced faster than old bone is broken down. The bones most commonly affected are the pelvis, skull, collar-bone, vertebrae, and the long bones in the leg. Symptoms may include pain, deformity, and a liability to fracture. If the skull is affected, there may also be deafness due to pressure on the nerves linked to hearing.
> Osteomyelitis: This disease, which is more common in children, is cause by bacterial infection and can affect any bone in the body. It causes gever, pain, tenderness and inflammation of the over-lying skin.
