Spontaneous resolution of "protruded" lumbar discs.

Decreasing size of disc material that has herniated, whether "contained" or "protruded" has previously been described and sometimes this can be so complete that residual material is barely visible. In a retrospective clinical survey, from among almost 2180 consecutive patients admitted during 1994 - 2002 with low back pain; due to our low follow-up ratios and high price of the magnetic resonance imaging (MRI), only 42 patients with a lumbar disc protrusion could be found who had two MRI scans obtained at least five weeks apart. Among these, 4 patients were spotted with a totally resolved disc protrusion. T (2)-weighted MRI images were suggesting shrinkage due to dehydration and regression within the annulus of protruded disc fragments that had not fully migrated. Our patients are further examples for total resolution of the large "protruded" disc without any treatment; and since concomitant disc protrusions at other levels persisted, the resolution of these discs is supposed to be spontaneous.