Bone mineral density

Increased bone mineral density

In the Statements of Principles for Osteoarthritis the RMA has defined increased bone mineral density to mean "a bone mineral density at least one standard deviation above the mean bone mineral density of young adult sex-matched controls".

General Information

Bone density, or bone mineral density (BMD) is a medical term referring to the amount of matter per square centimeter of bones. It is measured by a procedure called densitometry, often performed in the radiology or nuclear medicine departments of hospitals or clinics.  Measurements are most commonly made over the lumbar spine and over the upper part of the hip. The forearm is scanned if either the hip or the lumbar spine can't be. Average density is around 1500 kg m^-3.

While there are many different types of BMD tests, all are non-invasive. Most tests differ in which bones are measured to determine the BMD result.

The tests used to determine BMD include:

• Dual energy X-ray absorptiometry (DXA or DEXA)
• Quantitative computed tomography (QCT)
• Qualitative ultrasound (QUS)
• Single photon absorptiometry (SPA)
• Dual photon absorptiometry (DPA)
• Digital X-ray radiogrammetry (DXR)
• Single energy X-ray absorptiometry (SEXA)

DEXA and ultrasound are the most widely used.

Average bone mineral density = BMC / W [g/cm²]

• BMC = bone mineral content = g/cm
• W = width at the scanned line

Results are generally scored by two measures, the T-score and the Z-score. Scores indicate the amount one's bone mineral density varies from the mean. Negative scores indicate lower bone density, and positive scores indicate higher.

T-score

The T-score is a comparison of a patient's BMD to that of a healthy thirty-year-old of the same sex and ethnicity. This value is used in post-menopausal women and men over aged 50 because it better predicts risk of future fracture. The criteria of the World Health Organization are:

Normal is a T-score of -1.0 or higher

Z-score

The Z-score is the number of standard deviations a patient's BMD differs from the average BMD of their age, sex, and ethnicity. This value is used in premenopausal women, men under the age of 50, and in children.

Increase in bone density

An increase in bone density may be achieved by taking calcium and Vitamin D supplements, weight bearing exercise (such as walking) weight training, or by using certain medications such as calcitonin, alendromate, or actonel (mostly used for treatment of osteoporosis or other bone disorders like Paget's disease). Post menopausal hormone therapy may also contribute to increased bone density.

Establishing onset

If a person had an increased BMD as specified this would only have been established by radiological evidence. Such evidence would normally be recorded in doctors' notes and/or hospital records. However, these records may have been destroyed or can no longer be obtained. Therefore, if there is a reliable history of appropriate medical treatment at a particular time, this generally will be accepted, unless there is contradictory evidence. Seek medical advice if it is unclear whether the person's BMD meets the definition of the increased level as specified by the SOP requirements.

Preliminary questions [41670]

41671 there is some evidence that an increased bone mineral density may be a factor in the development of the condition under consideration.

41848  the veteran has claimed osteoarthritis of a relevant joint or joints for increased bone mineral density.

or

41851   the veteran has claimed osteoarthritis of an unspecified relevant joint or joints for increased bone mineral density.

41691  the veteran has osteoarthritis of a joint of the lower limb.

41672 the veteran had increased bone mineral density at some time.

41675  the veteran has established the causal connection between the increased bone mineral density and VEA service for the condition under consideration.

41676   the veteran has established the causal connection between the increased bone mineral density and operational service for the clinical onset of the condition under consideration.

or

41677   the veteran has established the causal connection between the increased bone mineral density and eligible service for the clinical onset of the condition under consideration.

Clinical onset and operational service [41676]

41679 the veteran had increased bone mineral density as defined in the Statement of Principles requirements.

41680 the veteran had an increase in bone mineral density during operational service.

41681 the veteran had the increased bone density due to operational service before the clinical onset of osteoarthritis.

or

41682 the veteran had the increased bone mineral density because of an illness or injury which is identifiable.

41683 as a consequence of the identified illness or injury, the veteran had the increased bone mineral density before the clinical onset of osteoarthritis.

41684  the identified illness or injury, which caused the increased bone mineral density, is causally related to operational service.

Clinical onset and eligible service [41677]

41679 the veteran had increased bone mineral density as defined in the Statement of Principles requirements.

41685 the veteran had an increase in bone mineral density during eligible service.

41849 the veteran had the increased bone mineral density as a casual result of eligible service.

41686 the veteran had the increased bone density due to eligible service before the clinical onset of osteoarthritis.

or

41682 the veteran had the increased bone mineral density because of an illness or injury which is identifiable.

41683 as a consequence of the identified illness or injury, the veteran had the increased bone mineral density before the clinical onset of osteoarthritis.

41687  the identified illness or injury, which caused the increased bone mineral density, is causally related to eligible service.