[Evocative lumbar discography].
Even though lumbar discography was described in 1948 by Lind Bloom as a useful diagnostic method to identify ruptures of the anulus fibrosus of the intervertebral disc, it was neglected for many years as an unreliable method. This happened especially after a publication by Holt, who in 1968 reported a 37% false-positive rate in a study done among inmates, with a very irritating contrast medium (hypaque) that was administered intrathecally.


OBJECTIVE
To show that lumbar discography is a dynamic and safe method and even more reliable than magnetic resonance imaging to detect intervertebral disc ruptures.


METHODS
Thirty-three patients with a clinical history of lumbosciatic pain lasting more than 6 months and an MRI-proven diagnosis of herniated disc were studied. Fifty discographies were performed at the L3-4, L4-5, L5-S1 spaces. They were considered as negative: (1) When the contrast had an oval or cotton-ball shape. (2) When the disc admitted 2-2.5 cm of contrast medium without causing any pain. They were considered as positive: When the contrast dye diffused with an irregular pattern. (2) When the administration of the contrast dye was painful. All negative discographies were followed-up for 6 months.


RESULTS
Thirty-three patients; 22 males, 11 females; 50 discographies as follows: 5 at L3-4; 27 at L4-5; and 18 at L5-S1. Five discographies were negative, At six months, the patients were asymptomatic. The discography detected 5 patients, equivalent to a 10% false/positive rate for the magnetic resonance imaging. Two patients developed diskitis.


CONCLUSIONS
Discography is more effective than magnetic resonance imaging for detecting intervertebral disc ruptures. Patients with diskitis were related with minimally invasive surgery, probably more due to the infectious process than to discography.
Montes García
Carlos
C
Hospital Poliplaza Médica, Cd. Juárez, Chihuahua. carlo104@prodigy.net.mx
Nava Granados
Luis Fernando
LF
D000328:Adult; D005260:Female; D006801:Humans; D007405:Intervertebral Disc Displacement / Q000175:diagnosis / Q000000981:diagnostic imaging*; D008159:Lumbar Vertebrae; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011859:Radiography; D015203:Reproducibility of Results