What Do We Mean By Bone Density?

In common terms, bone density is used as a synonym for bone strength. We generally imply that bones that are denser are stronger.

Bone density is actually bone mineral density. It is defined as the density of minerals per unit volume of the bone.

Bones richer in minerals, such as calcium, phosphorus, magnesium etc, are stronger and less prone to fractures.

How Do We Measure Bone Density?

Clinically, bone density is measured as a proxy. Optical imaging is done and optical density of a bone per square centimeter in taken as its bone density.

Optical density correlates with the actual mineral density of the bone. Mineral rich bone are definitely denser.

Bone Density Testing

To test bone density, DXA machine is used. This is essentially a dual energy X ray machine that checks the optical density of the bone.

How Is It Done?

Patient is made to lie down comfortable. Rays are usually passed through his spine area or the hip. The overall bone mass present would decide how much rays are able to penetrate. This gives an optical estimate of bone density.

What If The Hip Or Spine Cannot Be Measured?

There are cases where the patient may have a fracture in the pelvic area. Internal fixation, screwing or implants may be present.

In such cases, wrist may be used for bone density testing.

Who Should Go For A Bone Density Testing?

Any can go for this test. However, the following population may need to definitely get this test-

  • All post menopausal women
  • Men over 70 years of age
  • Post chemotherapy patients, any age
  • Post radiotherapy patient, any age
  • Any body who has a history of getting fractures again and again
  • Any one who has fractured his bone by a trivial injury
  • Patients complaining of constant back pain or leg pain
  • Nutritionally deprived
  • Having evident loss of height over time

What Is Osteoporosis?

Weakening of bones, making them brittle and liable to breakage is called osteoporosis. This is linked with a loss of bone density, that is, mineral depletion from the bone.

Bones are a stock house of minerals. Our body keeps taking minerals from it and also keeps replacing them as well. In conditions where replacement is not at par with using up of the mineral stocks, bones may gradually weaken and lose their density.

They appear less opaque on imaging and become prone to fractures.

Symptoms Of Osteoporosis

Earliest signs may include back pain.

In many, there’s no sign till the patient suffers a fracture and is tested for bone density there after.

Other signs may include loss of height, bending or curving of the spine with age, unable to bear weights, leg pain, etc.

Bone Density Results

These are given as T Scores

Understanding T scores

  • Normal T score count -1 or above
  • Osteopenia (low density bone) -1 to -2.5
  • Osteoporosis -2.5 or below