Aim: To review abnormalities reported on plain radiographic examination of the lumbar spine in patients referred with low back pain by general practitioners. Additionally, we evaluated and stratified the prevalence of these abnormalities by age. Finally, the diagnostic impact of lumbar spine radiography for the diagnosis of degenerative change, fracture, infection and possible tumour, was modelled.
Materials and methods: A retrospective review of 2007 radiographic reports of patients referred with low back pain for lumbar spine radiography to a large radiology department was performed. The reports were classified into different diagnostic groups and subsequently stratified according to age. The potential diagnostic impact of lumbar spine radiography was modelled by using the prevalence of conditions studied as pre-test probabilities of disease.
Results: The prevalence of reported lumbar spine degeneration increased with age to 71% in patients aged 65-74 years. The overall prevalence of fracture, possible infection, possible tumour was low in our study population: 4, 0.8 and 0.7%, respectively. Fracture and possible infection showed no association with age. Possible tumour was only reported in patients older than 55 years of age.
Conclusion: Although the prevalence of degenerative changes was high in older patients, the therapeutic consequences of diagnosing this abnormality are minor. The prevalence of possible serious conditions was very low in all age categories, which implies radiation exposure in many patients with no significant lesions.