The patient came to the clinic 29-October-2011 complaining of LBP for 6 months, left sciatica for 3 months with exacerbation of LBP and left sciatica the last 2 months. MRI done 20-October-2011 showing mild spondylolisthesis L5-S1 with mild extrusion left side. There was mild weak dorsiflexion left foot 4/5 with mild scoliosis. The patient was advised to keep in conservative treatment.

The patient then came 13-December-2011 claiming that he was doing well until the last 2 days, he progressed agonizing left sciatica .

On examination, the patient was limping and with inverted scoliotic stance. There is weak dorsiflexion left foot 3/5.

The patient was sent for new MRI of the lumbar spine which was done 14-December-2011 showing considerable extrusion of the disc of L5-S1 with complete left foraminal occlusion. There is mild spondylolisthesis L5-S1, which of no clinical significance. The MRI report was that the lesion was ganglion originating from the left L5-S1 facet.

Left S1 foraminotomy was performed. There is glistening mass compressing the left S1 root medial and posterior. Drilling of the lateral mass was achieved, so as to see the origin of the extruded mass, which proved to be a ganglion from the left lateral mass. It was removed and inspection of the annulus fibrosis of L5-S1 disc space was without any extrusion.

Routine closure of the wound. Smooth postoperative recovery with improvement of the power of  left foot.

The patient has mild degree of spondylolisthesis which is clinically of no significance. The de novo extrusion was the triggering factor for pain generation and further weak left foot.

The mass if a ganglion or an extrusion must be surgically resected, because it was hard in consistency and severely compressing the root.