The patient's son came to the clinic 25-September-2019 telling that his father complaining of LBP with right sciatica for 2 months with rapid deterioration of performed to him mini-invasive discectomy for bulge disc L4-5 in Turkey. After surgery, he could not walk . MRI lumbar performed after surgery 04-August-2019 showing severe segmental stenosis of L4-5 with spondylolisthesis of L4-5. The patient is a known diabetic  with arterial hypertension and hypothyroid.

On examination in 26-October-2019: He is limping with exaggerated scoliotic stance. SLRS was 60 degrees right side with pain and 70 degrees left side with less pain. There was weak dorsiflexion right foot -3/5.

The patient was sent for investigations: MRI lumbar spine done 26-October-2019 showed spondylolisthesis L4-5 with severe segmental stenosis. Dynamic studies confirmed this and pelvis X-ray showed intraossal cyst right femur at the level of greater trochanter with calcification above the grater trochanter. The patient telling that he suffered from this 27 years ago. Cardiac consultation was achieved and CT-angio was normal.

Transpedicular fixation L4-5 using XIA 3 system with cross connector 43 mm and 4 monoaxial screws 6.5x4.5 mm. Decompressive laminectomy L4 and partial of L5 with flavotomy L3-4 with foraminotomy left L5 root. There is a lot of scar at the right L5 axilla. Using MultiGen, bipolar motor stimulation of the right L5 root was not achieved even with 4 Volts. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to right L5 root  was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the right L5 root was not achieved with even 4 Volts. The patient was put in Reverse Trendelenburg position with Valsalva maneuver and hyperventilation. No CSF leak. The harvested bone was milt and applied lateral to the rods. Routine closure of the wound.

Smooth postoperative recovery. The power of the right foot slightly improved and the sciatica decreased. He was sent to the ward.

The XIA 3 system have many disadvantages. The finishing of the instruments is bad and needs improvement, including the cross connector.

It will be the last time. I will use it.

Despite the fact that the bone was marble in consistency, when applying the torque to the right upper screw, the right lower screw rotated medially, for what it was necessary to remove the rod and reposition the right lower screw to its previous position with more deep penetration.

The estimated recurrence rate is around 7%, because the disc space is not shallow.

This is the 189th case using the BPRF mode with MultiGen. This procedure regained routine acceptance.  It became a usual part of the spine and peripheral nerves surgery. Click here for reference.

It still unclear to evaluate the differences of pre and post application motor responses. The only sure thing that it tells that the electrodes did not migrate during the procedure and the nerve is functioning properly. Here the threshold of stimulation power of motor stimulation of the severely affected nerves did not improve after BPRF.

With accumulation of data, it became clear that the irritated nerve with aberrant currents running in the C fibers up, not only causing no change or elevation of the required voltage to achieve motor response, but they could cause the preoperative weakness. Ablation of such currents results in facilitation of the motor response and improvement of function with disappearance of pain.

It is unclear why the roots have several motor response with different patients, despite the fact that the neurological status is the same and the anesthesia protocol also the same.

It could be that the nerve is recovering minute by minute after decompression and this can explain why the motor conductivity is improving after the BPRF application, which require 4 minute session in most cases.

After the 172d case, the elevation of motor stimulation above 5 V was abandoned to avoid delayed dural tear with subsequent CSF leak, which take place at the contact at the lower electrode shaft with the dura below the level of the axilla.