Spinal Osteoarthritis is characterized by degenerative processes in the spine (spondylosis). A large variety of different shapes can be seen on X-rays. Height reduction of the intervertebral disk space, sclerosis of the endplates, and marginal vertebral osteophytes are typical for osteochondrosis inter- vertebralis whereas normal disk space and submarginal spondylophytes is characterizing spinal osteoarthritis. Because of this additional bone, the shape of the vertebrae changes: wedge shape or concave shape. While degenerative processes are associated with the above described os- teo- and spondylophytes as well as with height reduction of the intervertebral disc space (in case of osteochondrosis), those bone structures are usually not found in cases of osteoporotic vertebral fractures
Archive for the ‘Osteoporosis’ Category
Objective quantification of a vertebral fracture can be performed with morphometric measurements. Using a ruler, you can measure the anterior, middle, and posterior heights of the vertebral bodies on a plane X-ray film or digitally on screen (Figure 4). To calculate the grade of fracture, you divide each the anterior and middle height by the posterior height and multiply them with 100. The result is the percentage of deformity. Crushed fracture is defined as a fracture in which the posterior edge of the vertebral body is almost always involved. In order to calculate a crushed vertebra you divide the posterior height with the posterior height of the adjacent vertebral body above and/or below.
A vertebral body is called fractured if the a/p, m/p or p/p height ratio is D80%. This definition was applied in nearly all big international intervention studies and in big epidemiological studies (EVOS, EPOS).
Conventional X-rays in the diagnosis of osteoporosis: How to diagnose vertebral osteoporotic fractures?
Osteoporotic vertebral fractures are characterized by end plate deformities of different shape. Increased activity of osteoclasts generates increased numbers of Howship’s resorption lacunae on the surface of bone. Resorption first affects horizontal tra- beculae leading to a deterioration of the trabecular network. This increases the risk of trabeculae buckling, and consequently, vertebral endplates fracture. Deterioration leads to different shapes: wedge, concave, biconcave, or crushed. The diagnosis and classification of the shape of a vertebral fracture should be followed by the quantification of the fracture. Several approaches exist, but only two are important: a semi- quantitative and a morphometric analysis.
Semi-quantitative vertebral fracture analysis
During the basic diagnostic procedure, it is mandatory to X-ray the patient’s vertebral column in an anterior-posterior and later al projection because for differential diagnostics, it is important to exclude other diseases causing vertebral deformities. In follow-up studies one can reduce X-ray examination to lateral expositions of the spine.
Osteoporotic vertebral fractures occur only in the dorsal and lumbar spine and are extremely rare in the cervical spine and in the upper thoracic vertebral bodies. Therefore X-rays should depict.
The WHO definition of post-menopausal osteoporosis is based on the measurement of bone mineral density (BMD) with dual X-ray absorptiometry (DXA). Low DXA-BMD of the hip as well as poor results in the trail making and chair rising tests are risk factors of equivalent magnitude for vertebral fractures (Johnell, 2004(. Consequently, more diagnostic approaches are needed to complete the diagnostic procedure. The most important method to identify spinal fractures is conventional X-ray, particularly because >50% of spinal osteo- porotic fractures are not accompanied by clinical symptoms, and hence, remain unnoticed. Nevertheless, the diagnosis of vertebral fractures is important, because the prevalence of vertebral fractures is associated with an increased risk of incident fracture (Johnell, 2004; Felsenberg, 2004).
In this study, 68% of the physicians had low bone mass (12% had osteoporosis and 56% had osteopenia). We are unable to identify similar, published data on bone mass in a cohort of physicians; thus, this is a unique study. The results of NHANES III showed that the prevalence of low bone mass increases with age. In the general population, the prevalence of reduced bone mass in women 50-59 years old was 37% but increased to 87% among women 80 years and older. Our study revealed that osteoporosis was present in 33% of the cohorts in both the age group from 30-39 years old and the >60 years old group. This may be explained by the number of subjects in these two groups. These were the two largest age groups. It is difficult to compare NHANES III data with the data of this physician study. Our cohort was younger (mean age of 42 years old). Twenty-five percent of the group was under the age of 39 years. We are unable to find data on a young group with which to compare our data. Also, this study is a pilot study done on the population in an urban hospital with few Caucasian physicians. The National Osteoporosis Risk Assessment study (NORA), the largest recently reported study of that included minority women, showed that the risk of osteoporosis was 1.56 times greater for Asian women, 1.31 times greater for Hispanic women and 45% lower for African-American women, compared to Caucasian women. Other studies of minority groups showed that the risk for osteoporosis is low in African Americans. Our study was not designed to evaluate low bone mass density in various ethnic groups. However, in this study, more low bone mass density was evident in African Americans and Asians than in other ethnic groups. The Asians and African physicians had the largest percentage of persons with osteopenia (61%); they had no one with osteoporosis. For the Asians, the osteopenia may reflect the early start of osteoporosis (their mean age was 48 years), or it may be secondary to nutritional or genetic factors, or to a combination of age, nutrition, and genetic factors. Studies show that the peak bone mass attained at the end of adolescence is one of the principal factors that determines bone mass later in life. The finding of osteopenia in this group of young adult physicians strongly suggests that with continuous loss of bone mass they will progress to osteoporosis at a later age. One study indicated that Japanese women had lower peak bone mass than white non-Hispanic women. It may be that the Asian physicians studied had decreased peak bone mass. It should also be noted that in our study, one out of the 31 Asians was a strict vegetarian, and 10% of the 31 were lactovegetarians.
There were no differences between the physicians’ baseline age and sex demographics (Table 1). African Americans were the largest group studied (32%; 14 men, 18 women). The Asians were the next largest group (31%; 14 men, 17 women). The African group (18%) had 14 men and four women, whereas the Caribbean group (16%) had seven men and nine women. Also, there were two Caucasian men and one Hispanic man.