SERIAL MAGNETIC-RESONANCE-IMAGING FOLLOW-UP, STUDY OF LUMBAR DISC HERNIATION CONSERVATIVELY TREATED FOR AVERAGE 30 MONTHS - RELATION BETWEEN REDUCTION OF HERNIATION AND DEGENERATION OF DISC

The natural history of lumbar disc herniation in conservatively treate d patients is not entirely clear. This study was undertaken to clarify the relation between morphologic changes in the herniation and the cl inical course. Serial magnetic resonance imaging studies were performe d an average of 4.4 times in 30 patients in a 30-month-average period. The Japanese Orthopaedic Association (JOA) score and straight leg rai sing (SLR) test were improved, with the average reduction ratio of the herniation 15 and 18% on the sagittal and axial images, respectively. The JOA score and SLR test showed the most improvement within 1 year, with little change noted thereafter. In contrast, the disc herniation continued to reduce not only within 1 year, but also thereafter. Pati ents with progression of disc degeneration showed more marked regressi on of herniation than those in whom progression was not observed.