Prediction of successful discectomy using MRI quantitation of dural sac and herniated disc dimensions.
OBJECTIVE
To evaluate the ability of magnetic resonance imaging (MRI) quantitation of disc prolapse and dural sac to identify those who would benefit from discectomy.


METHODS
Thirty consecutive patients with disc herniation and leg pain who had MRI of lumbar spine and subsequently underwent discectomy were prospectively enrolled and compared with 30 controls. The anteroposterior (AP) diameter and the cross-sectional area of disc prolapse and of dural sac were measured. The ratios of AP diameters and cross-sectional areas were calculated. The measurements were correlated with the relief of symptoms based on a visual analogue scale assessment preoperatively and 1 week postoperatively.


RESULTS
All patients preoperatively had a pain score of seven or higher (mean +/- SD = 7.9 +/- 0.3) and postoperatively a score of < or = 2(mean +/- SD = 1.1 +/- 0.2). The AP diameter of disc prolapse and the ratio of AP diameters demonstrated the highest sensitivity and specificity: an AP diameter of 3.3 mm was 99% sensitive and specific and a ratio of the AP diameters of 0.37 was 100% sensitive and 99% specific.


CONCLUSIONS
Quantitative measurements of MRI can improve significantly the ability to identify the patients who would benefit from discectomy.
Pneumaticos
S G
SG
Department of Orthopaedic Surgery, University of Athens Medical School, Athens, Greece and Department of Orthopaedic Surgery, Baylor College of Medicine, Houston, TX, USA.
Chatziioannou
A N
AN
Hipp
J
J
Chatziioannou
S N
SN
D000005:Abdomen; D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D017586:Diskectomy / Q000379:methods*; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000601:surgery*; D008159:Lumbar Vertebrae; D053783:Magnetic Resonance Imaging, Interventional; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000209:etiology* / Q000517:prevention & control; D010388:Pelvis; D011446:Prospective Studies; D012372:ROC Curve; D011897:Random Allocation