Radiographic features of lumbar disc degeneration and self-reported back pain.

Abstract

OBJECTIVE: To characterize the occurrence of radiographic features of lumbar disc degeneration including the presence of osteophytes, endplate sclerosis, and disc space narrowing and to determine their relationship with self-reported back pain. METHODS: Subjects aged 50 years and over were recruited from a primary care based community health index in Aberdeen, UK. Subjects were invited to complete an interviewer administered questionnaire and to have lateral spinal radiographs performed. The questionnaire included questions concerning the occurrence of back pain, both ever and in the past year. The inter-vertebral disc spaces (L1/2 to L4/5) were evaluated for the presence and severity of anterior osteophytes, endplate sclerosis, and disc space narrowing using a semi-quantitative score (grade 0-3). Logistic regression was used to determine the association between these individual radiographic features of lumbar disc degeneration (using for each feature, the most severely affected vertebra) and back pain, with adjustments made for age and gender. RESULTS: There were 286 men (mean age 65.3 years), and 299 women (mean age 65.2 years) with spinal radiographs. Osteophytes were the most frequent radiographic feature. Osteophytes and endplate sclerosis were more frequent in men than women, but there was no gender difference in the frequency of disc space narrowing. All radiographic features increased in frequency with age; for osteophytes this was true only after excluding mild (grade 1) osteophytes. Compared to those without, those with disc space narrowing were more likely to report back pain both ever, [odds ratio (OR) = 2.1; 95% confidence interval (CI): 1.5 to 3.0] and in the past year (OR = 1.7) with the strength of the association increasing with increasing severity of narrowing. Endplate sclerosis was not linked with back pain although moderate (grade 2) sclerosis was associated with back pain, both ever and in the past year. Compared to those without, or those with mild osteophytes, those with more severe osteophytes (grade > 1) were more likely to report back pain ever (OR = 1.7; 95% CI: 1.2 to 2.5). CONCLUSION: These data highlight the frequent occurrence, and the increase in frequency with age, of the individual radiographic features of lumbar disc degeneration in population samples of men and women. Disc space narrowing appeared more strongly associated with back pain than the other radiographic features.