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.

Disc bulge with pressure on nerve root

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.

At the Centeno-Schultz Clinic  x-ray guided injections of PRP, platelet derived growth factors and mesenchymal stem cells are non-surgical options for debilitating lower back and leg pain.