Although they appear solid, bone is a growing, living tissue that constantly breaks down or remodeled. Bones consist primarily of collagen and calcium phosphate. When this process goes awry due to a disease or disorder, fractures and abnormal growth can occur. While osteoporosis remains one of the most well-known bone diseases, other diseases of bone that can also cause damage.
Osteogenesis Imperfecta
Osteogenesis Imperfecta, or OI, is a genetic disease that affects up to approximately 50,000 individuals in the United States, according to the National Institutes of Health (NIH). There are two kinds of OI; dominant and recessive. In dominant OI, the body makes too little type I collagen, or types I collagen of a poor quality. Since collagen is a protein that is part of connective tissues, if the amount or quality of collagen proves poor, this affects the "framework" of the bones, leading to weak and easily broken bones. Within the two kinds of OI, eight different types exist. Depending on the type of OI, symptoms can include easily fractured bones, brittle teeth, hearing loss, muscle weakness, severe bone deformity, small stature and spinal curvature. While no cure currently exists for this disease, treatments include preventing and controlling symptoms with physical therapy and surgical procedures, use of mobility aids like wheelchairs and clinical trials with various kinds of medications.
Paget's Disease of the Bone
In the United States, almost one million individuals have Paget's Disease of the bone, according to the NIH. In Paget's Disease, bones become larger and weaker than normal bones. Although it can affect any bone in the body, areas most often affected include the pelvis, spine, skull and leg bones. Though diagnosed more often in older individuals, it can occur in people of any age. Symptoms can include hip pain or arthritis, growth of the head, hearing loss, curvature of the spine, back pain, bowed legs and pain in the knee joints. Treatment includes drugs called bisphosphonates, which help relieve pain symptoms and slow disease progression. These drugs include alendronate (Fosamax) and risedronate (Actonel).
Osteoporosis
The National Osteoporosis Foundation estimates that in the United States, nearly 10 million individuals have osteoporosis, and approximately 34 million have low bone mass, called osteopenia, and is a precursor to osteoporosis. The term itself means "porous bone," and describes a condition in which low bone mass and deterioration of bone tissue occurs, leading to increased risk of fractures. The most commonly affected areas include the hip, spine and wrist. Though no cure for the disease exists, there are treatments. Drugs like bisphosphonates and other antiresorptive medications help slow down bone loss and sometimes help to build new bone mass.
