The patient was operated elsewhere 2004 for spondylolisthesis L5-S1. The patient improved slightly and the last 4 months got agonizing right sciatica. MRI lumbar spine done 12-November-2014, not informative. Micturition problems for 2 months.

On examination, the patient is limping with exaggerated scoliotic stance in pain with SLRS 20 degrees with pain in the right and 60 degrees with pain in the left. There is weak dorsi and planterflexion right foot -3/5 with hypalgesia below the right knee.

The patient was sent for investigations. MRI dorsal spine was normal and the lumbar ruling out the presence of discitis of escalation of other disci. LSS-X-rays dynamic showing loosening of the right construct with broken right lower screw. CT-scan with ORS Visual software showing the broken right lower screw ( See the picture below).

The four screws were exposed and the right transpedicular screws were removed. 2 polyaxial Medtronic Legacy CDH screws  6.5x45 mm were inserted from the right. The broken tip of the previous screw was left in place. In the left side the screws were acceptable and there was a heeled bone graft. In the right side there was no bone graft. Using Inomed technology, the roots were responding to 2-4 mA DNS stimulation and the right inserted rods did not respond even to 15 mA DNS stimulation. A 5.5 mm bended rod and cross connector were added to obtain stability of the area with bone graft applied lateral to the right rod. Routine closure of the wound.

Smooth postoperative recovery. The power of the right foot became better.

The broken screw made the right side of the spinal column unstable, which caused the sciatica.  Replacement of the right screws with cross connector must resolve the problem.