The patient was operated by me 01-July-2018 for extruded disc L4-5. The patient then came to the clinic 16-August-2018 complaining of LBP with left hip pain for 8 days without sciatica.

On examination was not limping, nor having scoliotic stance. SLRS was 80 degrees right side and 70 degrees left side with pain. There is no weakness.

The patient was sent for investigations and MRI lumbar spine performed 16-August-2018 showing recurrent disc L4-5 with left downward migration. Other investigations were uneventful.

Neurolysis of the left L5 root  with removal of the downward extrusion and left sided cleaning L4-5 disc space. A trail to insert the FIDES angular TLIF cage was performed from the same side and it was not inserted, because it needs transpedicular fixation. Otherwise without fixation and compression, it will provoke pseudoarthrosis and failed back syndrome. Using MultiGen, bipolar motor stimulation of the left L5 root was achieved with 2.7 V. A bipolar pulsed mode RF with 42 Celsius, 240 sec, 2 Hz and 20 msec duration to the left L5 root was achieved using 2 bended catheters 10 mm exposed length. Further bipolar motor stimulation of the left L5 root was achieved with 2.7 V. Routine closure of the wound.

Smooth postoperative recovery. He was sent to the ward.

There is continuous effort to resolve the recurrence without using transpedicular screws. For 2 years I am trying to use the SolidWorks, CATIA and Autodesk Inventor programs to construct the perfect device to resolve such problem.

More than 30 versions were constructed and seemed to be defective and not meeting the intended requirements.

I used here the FIDES angular cage, so as to see what are the problems which could face the intended final device to make it perfect. The shaver width must be 7-8mm width, the trail width also must be not 10 mm, but 7-8mm. The curettes are acceptable.

There is still an estimated postoperative recurrence around 7%, because the disc space height is not shallow.

This is the 164th 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 affected root after application was the same.

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.

The threshold of motor stimulation is high because of the scar. Presence of scar elevate the motor stimulation level 2-3 higher than the usual.