Addressing osteoporosis issues with your patients is an important aspect of chiropractic care

For many, osteoporosis conjures up images of stooped-over little old ladies. However, there is a huge population with undiagnosed osteoporosis who will potentially add significantly to the demands placed on the health care system if earlier methods of detection and treatment are not implemented.

PA and lateral radiograph of the wrist demonstrating a fracture of the distal radius associated with moderate to severe osteopenia.

Chiropractors, as primary care clinicians, have a duty not only to screen for the possibility of osteoporosis (referring to generalized osteoporosis, or more correctly, osteopenia when evaluating the bone density on plain-film), but also to determine the cause and then best advise the patient about various routes of treatment. The options include both traditional Western medicine and complementary approaches, and neither one should be excluded in favor of the other.

Poverty Stricken

With generalized osteoporosis (senile and postmenopausal), which literally means “poverty of bone,” there is a reduction in the quantity of bone that is most consistently visualized using plain-film.

Osteopenia refers to the radiological visible reduction in bone density on the radiograph, or an increase in radiolucency of bone.¹ However, this may be due not only to pathological states in the bone, but can also be simulated because of the type of radiographic technique, which is one of several reasons why plain-film radiography is not the technique of choice when assessing osteopenia.

A general rule when assessing bone density is that if the internal matrix of a vertebral body approaches the density of that of the surrounding soft tissues on a lumbar spine view, then the possibility that osteopenia is present is high. However, other signs are needed to determine the cause of osteopenia. These include fractures, pseudofractures (in osteomalacia), or underlying pathology, such as multiple myeloma—which causes a rapidly progressive diffuse osteopenia.

Although the most commonly discussed type of osteoporosis is postmenopausal or senile, which is generalized, there are additional subtypes:

1.    Regional osteoporosis: due to Reflex sympathetic dystrophy, also known as Complex regional pain syndrome, Sudeck’s atrophy, or Causalgia;

2.    Localized osteoporosis: due to disuse because of immobilization for fracture or poststroke; and

3.    Other unusual subtypes: including transitory osteoporosis, which affects the hip and usually recurs in the lower limb, and regional migratory osteoporosis, which occurs in one region and then regresses only to recur in another region, often the shoulder.

Bone is a living tissue and as such, it is constantly undergoing remodeling related to the stresses that are placed on it (Wolffs law) as well as the biochemical homeostasis that it assists in maintaining. When more bone is resorbed (by osteoclast cells) than is being laid down by osteoblast cells, then the disparity of bone becomes evident and osteopenia occurs. There are about 10 times as many osteoclasts as there are osteoblasts.² Many conditions may lead to generalized osteoporosis (see Table 1) depending on which part of the bone formation/resorption cycle is being affected.

Plain Film Talk

How can radiographs help diagnose osteoporosis? Although a suggestion of osteoporosis can be detected using plain-film radiography, the multiplicity of factors that can simulate such findings—not least of which is the radiographic technique—mean that this is not the best modality.

However, on a lateral lumbar spine film, if the internal matrix of a vertebral body is similar to that of the surrounding soft tissues of the abdomen with otherwise normal parameters, this suggests that the patient may have osteopenia. But remember that if older patients have a reduction in bone density, clinicians taking the films generally tend to overexpose and not compensate for reduced bone density, which in itself might simulate osteopenia. There may be accentuation of the vertical trabeculae and very thin end-plates—the so-called “pencil-thin cortices”—present too, but again this may be challenging depending on the quality of the radiograph.

In addition to the bone density, radiographs can be used to determine some of the secondary signs of osteoporosis, which include compression fractures of the spine—the anterior height should be reduced only, whereas the posterior height should be maintained in such cases. Vertebral body fractures demonstrating loss of the posterior body height usually indicate the presence of a pathological fracture due to metastatic deposits. In addition to vertebral body involvement, osteoporosis predisposes to fractures of the subcapital region of the hip, and the distal radius—the Colles’ fracture.

An additional method of evaluation was proposed by Singh using the third metacarpal midshaft region. It was proposed that the cortex and medulla be measured and then compared. If the width of the two cortices measured half or more than the whole width of the bony digit, then the bone density was considered to be within normal limits. If the combined cortices were less than half the width of the whole digit, then the suggestion of osteoporosis could be entertained. Also remember that there has to be a 30% to 50% bone loss in order to detect a decrease in bone density on plain-film.

If plain-film radiography is not the answer to diagnosing osteoporosis, then what is the gold standard to evaluate, predict, and prevent potential complications? During the past 10 years, a gamut of tests has been introduced to measure bone density. These have ranged from single-photon absorptiometry through to quantitative computed tomography.³ The latter is perhaps the most recent advance but requires a substantial radiation dose and is expensive to perform. The most widely used test is the dual energy X-ray absorptiometry (DEXA) scan, which represents an inexpensive, easy, effective, and fast way to assess bone density.

Sticks and Stones

Education is the key to fighting this disease, and the earlier it is initiated, the better the prognosis for the patient. Make sure the dietary intake of calcium and vitamin D is adequate for the demands patients are making on their bodies. The recommended amount is approximately 1,000 mg per day for adults, 1,000 mg to 1,500 mg perday for postmenopausal women, and 1,200 mg per day for adolescents. Exposure to sunlight is perhaps the easiest way to obtain enough vitamin D.

It is also important to include additional nutrients in the patient’s diet, including vitamins B6, B12, and K, as well as some trace elements such as manganese and chromium. A special note should be made if patients exhibit signs or symptoms of malabsorption, since this will obviously affect their ability to absorb nutrients—they need a full evaluation with a qualified dietician. Regular load bearing exercises are recommended. Smokers should be strongly advised to stop, and alcohol should be limited. Women should be counselled on the possibility of hormone replacement therapy and the alternatives.

As for patients who have already been diagnosed, the widely accepted school of thought is that once osteoporosis has occurred, treatment options are limited. But there are certain treatments still available. Conventional medicine has a number of drugs that may be used, such as Fosamax and a newer medication, Raloxifene. The latter drug is a selective estrogen receptor modulator that actually mimics the effects of estrogen on bone, and some trials have even shown that there is an increase in bone density with some of these patients.⁴ However, this is only beneficial in women.

What about male patients that suffer from osteoporosis? This is one of the most underinvestigated, and yet one of the most potentially significant disorders. The majority of drug studies performed have been done on women, which has led to difficulties in medication available to men. Seeman⁵ mentions that only one study to date looked at the effects of alendronate on men. This is clearly an area that needs to be addressed.

Michelle Wessely, BSc (chiropractic), DC, DACBR, FCC (radiology) is a radiology research fellow at the Department of Osteoradiology, Veterans Affairs Healthcare Center, San Diego. She graduated from the Anglo-European College of Chiropractic, Bournemouth, UK, and is in California for 1 year as a bone fellow for Donald Resnick, MD, professor of radiology. Wessely can be reached via email: michelle_wessely@hotmail.com.

References
1. Resnick D. Osteoporosis. In: Diagnosis of Bone and Joint Disorders. Vol 4. 3rd ed. Philadelphia: WB Saunders; 1995:1783–1854.
2. Hock JM, Krishnan V, Onyia JE, Bidwell JP, Milas J, Stanislaus D. Osteoblast apoptosis and bone turnover. Journal of Bone Mineral Research. 2001;16(6):975–984.
3. Yochum T, Rowe L. Diagnostic imaging of the musculoskeletal system. In: Essentials of Skeletal Radiology. Vol 1. 2nd ed. Philadelphia; Williams and Wilkins; 1996:373–545.
4.     Johnell O, Schell WH, Lu Y, Reginster JY, Need AG, Seeman E. Additive effects of raloxifene and alendronate on bone denisty and biochemical markers of bone remodeling in postmenopausal women with osteoporosis. Journal of Clinical and Endocrinology Metabolism. 2002;87(3): 985–992.
5.     Seeman E. Unresolved issues in osteoporosis in men. Review of Endrocrine and Metabolic Disorders. 2001;2(1):45–64.