Relationship between severity of lumbar disc disease and disability scores in sciatica patients

To study the association between the clinical examination and the radiological assessment of lumbar disc disease in patients with sciatica.

The study included 394 consecutive sciatica patients. The patients' disabilities were evaluated by a visual analog pain scale, the Prolo functional-economic rating scale, the modified Roland-Morris disability questionnaire, and the health-related quality of life short form (SF-36) questionnaire. Radiological imaging findings were independently classified according to the Modic criteria into five groups of increasing severity of disc disease. Stepwise multivariate logistic regression was used to determine which scores were significant independent predictors of a severe disc disease (extrusion or sequestration).

Of these patients, 9.6% had no disc disease, 3.3% had a bulging, 11.4% had a protrusion, 68.5% had an extrusion, and 7.1% had a disc sequestration. Statistically significant positive linear associations with the severity of disc disease were found for the leg pain scale, the Roland-Morris and Prolo disability scales, and the SF-36 scores related to physical functioning, physical role, and bodily pain (all P < 0.005). A poor (<5) Prolo score (odds ratio, 2.91; 95% confidence interval, 1.74-4.87), a higher leg pain score (odds ratio, 1.16 per centimeter increase; 95% confidence interval, 1.07-1.27), and a lower low back pain score (odds ratio, 0.90 per centimeter decrease; 95% confidence interval, 0.82-0.98) were retained in the multivariate logistic model as independent predictors of severe disc disease.

The positive correlation between disability status and imaging findings validates both assessment methods. Routine use of disability scores brings a useful contribution to the assessment of sciatica patients.