The patient was operated by me 02-November-2019 for transpedicular fixation. The patient was diabetic and the power of the right foot improved and due to oozing of the wound the discharge was delayed. The patient was telling that there is still LBP and check X-ray was OK. CT-scan of the spine after reconstructing it with ORS Visual, showed the lower right screw in unacceptable position, for what revision of this screw was mandatory. See the fig-1 below.

The wound was opened and the nuts of the right screws and cross connector were removed. The right rod was pushed outside. The right transverse process was exposed properly. Using the C-arm, the right lower screw was removed and polyaxial screw same dimensions inserted abut to the transverse process with 15 degrees of the Saggital plane. Check C-arm in different projections showed acceptable position of the screw. Further extended foraminotomy of L5 was performed. The root is not responding even to 4 V. Larger size cross connector was applied. Routine closure of the wound.

Smooth postoperative recovery. 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 C-arm can mislead you, also the X-rays. The best way is to have intraoperative CT-scan.

The bad system will lead you to wrong mishaps. The unknown previous surgeries also will make the natural landmarks lost. This led us to redo surgery to correct the position of the lower right screw.

This is the 190th 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.