Bone

Introduction

Bone is a dynamic tissue which is being replaced and remodelled throughout life. The necessary equilibrium between bone production and resorption becomes unbalanced in later life. The result is a gradual and progressive loss of bone after the age of 35.

Bone loss is normally 0.2% of total bone mass per year after the age of 35 , rising to 1% per annum in post-menopausal women, i.e., by the age of 80, women will have lost about 30% of their original bone mass whilst men, 10%.

Bones become less- dense partly because the amount of calcium they contain decreases. Part of the reason is that less calcium is absorbed in the digestive tract and levels of vitamin D (which helps the body absorb and use calcium) decrease slightly. Calcium is the main mineral that gives bones strength. Certain bones are weakened more than others. Those most affected include the end of the thighbone (femur) at the hip, the ends of the arm bones (radius and ulna) at the wrist, and the bones of the spine ( vertebrae).

At the center of bones is bone marrow, where most blood cells are produced. As people age, the amount of bone marrow decreases. Therefore, fewer blood cells are produced. Even with this decrease, the bone marrow can usually produce enough blood cells throughout life .  Problems may occur when the need for blood cells is greatly increased.

Symptoms and Signs

Osteoporosis is defined as a systemic skeletal disease characterised by weak and brittle bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. The strength of your bones depends on their mass and density. The brittle and weak bones are caused by low levels of calcium, phosphorus and other minerals in your bones. There is a marked increase in the incidence of osteoporosis among the older age group especially in menopausal women.

Osteoporosis is a silent disease without any symptoms in most patients until fracture has occurred. Risk factors for osteoporosis are: premature menopause (<45 years), low calcium intake, sedentary lifestyle, cigarette smoking, long- term treatment with steroids, excessive alcohol and caffeine intake. In the aged bone marrow, the ability to produce more blood cells in response to anaemia, infection or excessive bleeding may be impaired

Complications

  • Fracture may occur especially at end of thigh bone, wrist and back bone. Pain will be present and sometimes persistent.

  • Deformity – kyphosis (dowager’s hump), due to vertebral collapse, leads to shortening, with reduction in crown-to-pubis measurement.

Treatment

  • Find out the causes and risk factors of osteoporosis.

  • Pain killer if necessary.

  • The appropriate treatment for osteoporosis.

  • Surgery may be needed in fractures.

  • See a doctor

Prevention

  • Healthy life style – exercise helps you build stronger bones and slow the rate of bone loss. Don’t smoke and avoid excessive alcohol.

  • Get adequate calcium and vitamin D. Take calcium about 1500mg/day and vitamin D about 400 to 800IU/day.

Last Review : 20 June 2014
Writer : Dr. Sanidah binti Md. Ali
Reviewed : Dr. Juriati bt Ismail