DATE OF OPERATION: MM/DD/YYYY
PREOPERATIVE DIAGNOSIS: Spinal stenosis, L3-L4, secondary to degenerative spondylolisthesis, status post L4-L5 fusion.
POSTOPERATIVE DIAGNOSIS: Spinal stenosis, L3-L4, secondary to degenerative spondylolisthesis, status post L4-L5 fusion.
OPERATIONS PERFORMED:
1. Anterior interbody fusion with reduction of spondylolisthesis and placement of CoRoent interbody cage with bone morphogenetic protein via transpsoas approach.
2. Laminectomy and lateral decompression, L3-L4.
3. Posterior fusion, L3-L4.
4. Removal of segmental fixation, L4-L5.
5. Posterior fixation using Theken pedicle screw fixation, L3 to L5.
6. Local bone graft.
SURGEON: John Doe, MD
ASSISTANT: Jane Doe, PA-C
ANESTHESIA: General.
ESTIMATED BLOOD LOSS: 350 mL.
NEEDLE AND SPONGE COUNTS: Correct.
DRAINS AND PACKS: Medium Hemovac drain, lumbar spine.
SPECIMENS: Hardware removed.
SKIN CLOSURE: 4-0 Vicryl subcuticular.
DESCRIPTION OF OPERATION: The patient was brought to the operating room and given a general endotracheal anesthetic. She was then placed in a right lateral decubitus position and the table flexed in order to increase the distance between the ribs and iliac crest on the left-hand side. Sterile prep was done with Betadine and she was draped in a sterile manner. A straight lateral approach to the lumbar spine through a transpsoas approach was performed. A small incision over the iliac crest was made. The internal, external oblique and transverse abdominal muscles were identified and gently dissected apart and then blunt dissection was used to enter into the retroperitoneal space and find the psoas muscle. Blunt dissection through the psoas muscle down to the L3-4 disk space was performed. The invasive retractor was then placed by first putting the dilators through the psoas muscle at L3-4 and inserting the guide pin into the appropriate position in the bar into the disk of L3-4, approximately in the center of L3 and slightly anterior on L4. X-ray was used for guidance and placement of this. We also used EMG studies to confirm appropriate resistance and testing the L3 and L4 nerve roots. The retractor was then placed down over the dilators and attached to the arm, which secured it to the table. The jaws of the retractor were then gently spread and the underlying disk seen. Overlying muscle fibers were dissected away until the lateral border of the disk could be seen. We checked the wound with EMG and found the impedance numbers to be appropriate. A window was cut into the disk space of L3-4 and then the contents of the disk removed. The disk was badly degenerated, and essentially, there was no material left within the disk itself. Distraction was able to be performed up to about 8 mm initially. I was able to release the annulus of the disk on the opposite side.
Once the contents of the disk were removed adequately, the trial cages for the CoRoent system were inserted. We were able to get up to a 10 mm cage very easily, and using this 10 mm cage, a ligamentotaxis resulted in a near complete reduction of the L3-4 disk. The actual cage was then placed on the inserter. Bone morphogenetic protein had been allowed to soak into the collagen sponge for approximately 20 minutes. The appropriate amount was placed into the windows of the cage and the cage inserted into the prepared disk space. Using x-ray to guide, it was placed into the appropriate position. The retractor was removed and the fascia closed with 0 Vicryl, 2-0 Vicryl and Steri-Strips. The drapes were then removed and the patient rolled over onto another table on a Wilson frame in a face-down position. Sterile prep was done with Betadine and she was draped in a sterile manner again. Previous scar was identified and then excision extended above this about an inch or two. The dissection was carried down until the spinous processes of L2 and L3 were identified. We cleaned the lamina of these out over the facets of L3-4 and L2-3 and exposed the transverse process of L3. Screws were identified along with a crosslink. These were cleaned of overlying soft tissue as well and removed using the appropriate instrumentation. The screws that had been in place were steel CD Horizon instrumentation. This was removed without difficulty. They were not loose and testing revealed that there was a solid fusion at L4-5.
Following the removal, a laminectomy was then performed at L3-4. L4 lamina had been removed completely previously. The L3 lamina was removed with rongeur. The bone fragments from this were saved for grafting posteriorly. The lamina was thinned out and then 3 and 4 mm Kerrison rongeurs were used to remove the remainder of the lamina until the L3 and L4 pedicles were palpated. It was noted at this time that there was a pars defect on the right at L3. The facet joint was greatly widened, and especially, in the now reduced position, there was a large gap between the superior facet of L4 and the inferior facet of L3. Care was taken to identify the L4 nerve root to make certain it was not decompressed in the lateral gutters. There was considerable hypertrophy and soft tissue in this area, which was removed. The L3 nerve root was traced out into the foramen on both sides to make certain it was not compressed. Once full neural decompression had been performed, pedicle screws were placed into the L3 vertebral body. The routine technique for identification and cannulation of the L3 pedicle was performed and 45 mm x 6.5 mm diameter screws from the Theken system were used. At L4 and L5, the holes were carefully sounded. Preoperative CT had been reviewed and the screws were all noted to be within bone, although the one on the right, at L5, was somewhat lateral. The screws were felt to be a little bit long and we wanted to set them a little bit more deeply to facilitate engaging the rod into all screws and so each of the screws at L4 and L5 were shortened to a 40 mm length.
Good fixation was obtained. A rod was bent to appropriate contours and placed into the caps of the pedicle screws and the cap screws tightened down firmly over the rod. Intraoperative x-ray showed good placement of the screws and the cage. Screws were tightened with the appropriate torque wrench. There was not sufficient space to place a crosslink between L3 and L4, and it was not felt it would be of any benefit to place one between L4 and L5 as this segment was firmly fused. Final irrigation was performed. Prior to placement of the screws and rods, the transverse process of L3 and the superior portion of the previous fusion had been rongeured and burred to cancellous bleeding bone, and the bone graft was placed into this prepared area. Duramorph, Avitene, Depo-Medrol was placed into the laminectomy site. This had been irrigated out well previously and the dura inspected. There was no evidence of damage to the lamina or nerve roots. The retractor was then removed and the wound closed with interrupted #1 Vicryl on the deep fascia, 2-0 Vicryl subcutaneous, 4-0 Vicryl subcuticular. A medium Hemovac drain was placed prior to closure. Dry dressing was applied. The patient was rolled over on her back, awakened, extubated and taken to recovery in stable condition.
