This protocol can help surgeons master surgical procedure on a modified technique. Unilateral posterior vertebral column resection with modified trephine which is used to treat thoracolumbar kyphotic deformity. This technique can reduce operation time, blood loss, the trauma to patients during the surgeries and this technique is easy to learn.
To begin, make a median dorsal incision centered on the diseased vertebra with a scalpel, covering two vertebral bodies above and below. To ensure the pedicle screw can be placed in, keep the incision length longer than the two vertebrae adjacent to the lesion on each side. Use a scalpel to cut the skin and subcutaneous tissue vertically along the mark.
Then, stop the bleeding using bipolar coagulation. Using electrocoagulation electrotome to separate the latissimus dorsi and multifidus muscles along the muscle attachment points until the posterior spinous process and vertebral plate are revealed. Use osteo forceps to remove part of the facet joints of the two vertebrae above and below the lesion until the articular surface is completely exposed.
Then, use the positioning needle to confirm the correct position of the pedicle screws under C-ARM guidance. Choose the entry point, 0.3 milliliters coddle to the junction of the transverse process in the thoracic vertebra. The entry point of the lumbar vertebra is the intersection of the horizontal line of the transverse processes midpoint and the vertical line of the superior articular process.
Insert eight pedicle screws bilaterally in the upper and lower segments using a reaming probe to expand the path. Depending on the disease, insert another pedicle screw on one side of the lesioned segment. If the patient suffers from osteoporosis, use bone cement injectable cannulated pedicle screws to strengthen the vertebral bodies.
Place a temporary fixation rod opposite the osteotomy side on the pedicle screw caps and fasten the nuts. Then use a rongeur to excise the lesion's segments spinous process. Next, use the laminectomy rongeur to remove the lamina adjacent to the spinous and inferior articular processes on the osteotomy side.
Following these procedures, use the rongeur to cut off the transverse process on the same side. Perform the osteotomy in the surgery using a modified trephine. First, insert the pedicle probe into the lesioned vertebra.
Then use a modified trephine to remove the bone by twisting the handle into the vertebra. When the top of the trephine reaches the tip of the probe, the locking instrument will restrict its movement and prevent the serrated top from injuring the anterior tissue. Hold on to the trephine and probe, then slowly pull them out and collect the cancellous bone in the trephine for later use.
Then repeat the same procedure to remove the bone quickly. Sometimes the bone may not come out with the trephine. Use a nucleus pulposus clamp to remove it.
Remove the contralateral bone by changing the angle of the probe and ensuring that the trephine does not injure the nerves, preserving the vertebral arch and part of the bone. Next, use the laminectomy rongeur and nucleus pulposus clamp to remove the remaining small cancellous bone fragments and discs, then, use a curette to scrape the upper and lower end plate cartilage. The osteotomy will be complete when the space is large enough to implant the titanium mesh.
Under the isolation of the dura by the nerve dissector, use the reverse curette and osteotome to remove the posterior wall of the vertebra. Once the compression to the spinal cord is relieved, gently pull the spinal cord into a position where the titanium cage can be safely implanted. Be careful not to damage the spinal dura mater to avoid cerebrospinal fluid leakage.
Remove the temporary fixation bar and place an orthopedic rod pre-corrected to the proper curvature. Screw and fasten the nuts on the opposite side of the osteotomy. Fill an appropriately sized titanium cage with the amputated autologous bone.
Then place it in the correct position to prevent forward flexion of the spine. Implant the autologous fragmented bones, peripherally. Place another fixing rod with the same curvature as the rod placed previously on the osteotomy side and screw and fasten the nuts.
Use a large amount of saline to flush the operative field and stop active bleeding with bipolar electrocoagulation. Then, use gelatin sponges to fill the void and insert one or two closed suction drains to prevent postoperative hematoma. Close the incision layer by layer and ensure that each layer is not sutured to the drains.
Use interrupted absorbable sutures to suture the muscle and continuous absorbable sutures to close the fascia. Use a skin stapler to close the skin. Combining the unilateral PVCR technique and modified trephine allowed removal of the lesions and rebuilding of spinal stability for patients with Kummell disease, especially for patients with kyphotic deformity and obvious nerve-oppressed symptoms.
The nerve roots and the spinal cord must be protected to prevent severe posterior neurological complications during the surgery.
