The distribution, determinants, and clinical correlates of vertebral osteophytosis: a population based survey.
O'Neill TW., McCloskey EV., Kanis JA., Bhalla AK., Reeve J., Reid DM., Todd C., Woolf AD., Silman AJ.
OBJECTIVE: Vertebral osteophytes are a characteristic feature of intervertebral disc degeneration. There are, however, few population data concerning the occurrence of and clinico-biological correlates of vertebral osteophytes in both the dorsal and lumbar spine. Our purpose was to determine the frequency and distribution of anterior osteophytes in the thoracic and lumbar spine, and their relationship with both various putative risk factors, including physical activity and obesity, and self-reported back pain. METHODS: Men and women aged 50 years and over were recruited from primary care based registers in 5 UK centers. They were invited to attend for an interviewer administered lifestyle questionnaire, assessment of height and weight, and lateral spinal radiographs. Lateral spinal radiographs were evaluated by a single observer for the presence of osteophytes from T4 to L5 using a semiquantitative score (grade): 0 = none, 1 = doubtful, 2 = mild, 3 = moderate, 4 = severe. Based on these data 2 summary statistics were derived: the maximum osteophyte grade at any vertebral level (MAX), and the sum of the osteophyte grades at the individual vertebral levels (TOT). RESULTS: In total, 681 women, mean age 63.3 years, and 499 men, mean age 63.7 years, were studied; 84% of men and 74% of women had at least one vertebral level with a grade 1 or higher osteophyte. Both the sum of the individual grades (TOT) and the proportion of subjects with MAX > or =2 were greater in men than in women in both the dorsal and lumbar spine, and both increased with age. The pattern of spinal involvement was similar in the sexes, with osteophytes occurring most frequently at T9-10 and L3. Increasing body mass index was associated with more frequent osteophytes at both dorsal and lumbar spine, although the relationship was stronger at the dorsal spine. Heavy physical activity, particularly in young adult life, was associated with osteophytosis in men. Self-reported back pain, both ever and in the past year, was linked with lumbar osteophytes in men. CONCLUSION: The distribution within the spine in our study and the relationship with heavy physical activity points to mechanical factors being important in pathogenesis of vertebral osteophytosis. Prospective studies are needed to explore the types of physical activity that increase susceptibility to vertebral osteophytosis. In men, osteophytes affecting the lumbar spine are associated with back pain.