Discectomy is the surgical removal of a portion of the disc that is thought to be causing pain. The disc may have a bulge (distention) which presses on a nerve root causing leg pain(sciatica). Removal of the disc bulge is intended to relieve pain.
How successful is lumbar discectomy? Not particularly. Loupasis examined long-term outcomes after lumbar discectomy.
The long-term results of standard lumbar discectomy are not very satisfying. More than one-third of the patients had unsatisfactory results and more than one-quarter complained of significant residual pain. 7.3 % of patients required additional lumbar spine surgery frequently due to repeat herniation. A predisposing factor to poor surgical outcomes was a job requiring significant physical activity.
Surgery weakens the annulus (side wall of the disc) predisposing the disc to re-injury and herniation as illustrated in this video.