[Disc alterations of lumbar spine on magnetic resonance images in asymptomatic workers]

to determine abnormal findings of the lumbar spine on magnetic resonance images in asymptomatic subjects.

prospective, transverse and descriptive study, in workers of the Instituto Mexicano del Seguro Social without low back pain; they were invited to be observed with magnetic resonance images of lumbar spine. A total of 105 cases was interpreted by a radiologist, who did not know the patients' clinical conditions. 107 lumbar spine alterations studies were mixed in order to not influence in the results, and they were not included in the statistic analysis.

55 % of the cases had discal alterations, 38 % presented bulging disk and 17 % presented protrusion. Other alterations were Schmorl's nodule, osteocondrosis, espondilolistesis, and annular tears.

bulging disk and discal protrusion frequency have high prevalence in magnetic resonance images in healthy individuals, so its presence in symptomatic patients is not necessarily cause of low back pain.