THE CORRELATION BETWEEN MAGNETIC-RESONANCE-IMAGING AND THE OPERATIVE AND CLINICAL FINDINGS AFTER LUMBAR MICRODISCECTOMY

Fifty-four consecutive patients were studied prospectively with magnet ic resonance imaging before microdiscectomy, and the findings correlat ed with clinical symptoms before and after operation, A sequestrated f ragment was found in 59% of cases, a subligamentous disc sequestration in 25% and a disc protrusion in 16%, The levels operated on were L4/5 - 36%, L5/S1 - 62.5%, and one at L3/4; 71% were laterally placed 10% lay intraforaminal and 10% medial. The diameter of the protrusion was 4 mm to 13 mm for the craniocaudal extension, and 5 mm to 18 mm for th e anteroposterior extension. No correlation could be found between a n eurological deficit and the size of the prolapse. A positive correlati on was present between the increasing degree of canal obstruction and the degree of disc degeneration determined by imaging for extrusions, subligamentous disc sequestrations and free sequestrations. Nerve root inflammation and enlargement was seen in 36% of the images, correspon ding to an operative finding of 32%, Magnetic resonance imaging is a h elpful preoperative diagnostic investigation which shows structural ch anges in the disc and the correct localisation and size of the disc se questration, but there was no correlation between the imaging findings and the clinical symptoms.