Minimally Invasive Surgery
MIS Cervical Foraminotomy
Minimally Invasive Cervical Foraminotomy
This is a MIS cervical foraminotomy decompression procedure that enlarges the space in which a spinal nerve root exits the cervical spinal canal (intervertebral foramen). This narrowing can be caused by a herniated disc, bone spurs, thickened ligaments or joints, which may result in painful pinched nerves. The procedure is performed from the back (posterior) with the patient on his or her stomach. See a video about herniated discs here.
A 1- to 2-cm incision is made on the symptomatic side of the neck. Using an operating microscope and x-ray guidance, the muscles are gradually dilated and a tubular retractor inserted to allow access to the cervical spine. Bone or disc material and/or thickened ligaments are then removed to decompress and relieve pressure on the spinal cord and/or nerves. The tubular retractor is removed, allowing the dilated muscles to come back together, and the incision is closed. This procedure typically takes about 2 hours to perform.
A multicenter retrospective chart review of 73 patients who had MICF showed the following results within a 40-month follow-up period:
At 40 months, 21 percent of patients had radicular symptoms with 11 percent reporting recurrence of preoperative symptoms and 9 percent with radicular symptoms of a different pattern. Nine of the 73 patients required cervical fusion within the 40-month period.
MIS Decompression and Fracture Treatment Procedures
- Microendoscopic Laminectomy
- Minimally Invasive Cervical Foraminotomy (MICF)
- Vertebroplasty and Kyphoplasty
Microdiscectomy, also called microlumbar discectomy (MLD), is a very common MIS decompression procedure performed in patients with a symptomatic lumbar herniated disc. The operation consists of removing the portion of the intervertebral disc that is herniated and compressing a spinal nerve root. The procedure is performed from the back (posterior) with the patient on his or her stomach. See a video about herniated discs here.
A 1- to 2-cm longitudinal incision is made in the midline of the lower back, directly over the area of the herniated disc. Special retractors and an operating microscope are used to visualize the region of the spine, with minimal or no cutting of the adjacent muscles and soft tissues. After the retractor is in place, an x-ray is used to confirm that the appropriate disc is identified. A small amount of bone of the superior lamina may be removed first to expose the disc herniation. The nerve root and neurologic structures are protected and carefully retracted so that the herniated disc can be removed. Surrounding areas are checked to ensure that no additional disc fragments are remaining. This procedure typically takes about 1 hour to perform.
Numerous research studies published in medical journals show that 90-96 percent of patients have good or excellent results from microdiscectomy surgery. Most patients experience a rapid decrease in pain and return to normal function.
Minimally Invasive Posterior Lumbar Interbody Fusion (PLIF)
This is a MIS technique that is performed in patients with refractory mechanical low back and radicular pain associated with spondylolisthesis, degenerative disc disease, and recurrent disc herniation. The procedure is performed from the back (posterior) with the patient on his or her stomach.
Using x-ray guidance, two 2.5-cm incisions are made on either side of the lower back. The muscles are gradually dilated and tubular retractors inserted to allow access to the affected area of the lumbar spine. The lamina is removed to allow visualization of the nerve roots. The disc material is removed from the spine and replaced with a bone graft and structural support from a cage made of bone, titanium, carbon-fiber, or a polymer, followed by rod and screw placement. The tubular retractors are removed, allowing the dilated muscles to come back together, and the incisions are closed. This procedure typically takes about 3 to 3 1/2 hours to perform.
In a study of 31 patients who underwent the MIS PLIF surgery, there was less blood loss, tissue trauma and operative time, quick recovery and bony fusion. In two patients, the pedicle screws were not ideally positioned, but there was no nerve root irritation or fixation failure and thus no revision was required. The overall short-term outcomes were excellent
Minimally Invasive Posterior Thoracic Fusion
Thoracic spinal fusion may be indicated for the surgical treatment of a wide range of conditions, including trauma, deformity, tumor, and infection. Conventional open surgical procedures for treatment of thoracic spine disease can be associated with significant approach-related morbidity. Recent advances in technology have led to the development of posterior MIS approaches for thoracic fusion. In a posterior thoracic fusion, the surgical approach to the spine is from the back through a midline incision. Special retractors are utilized, in addition to fluoroscopy, which provides intraoperative x-ray images of the spine. Monitoring equipment is used to determine the placement of the instruments in relationship to the spinal nerves. At present, thoracic MIS techniques are primarily used for stabilizing traumatic injuries, although some surgeons may use these techniques for treatment of tumors, infections, or degenerative disc disease. These procedures typically take about 3 to 3 1/2 hours to perform, although with more complex spinal disorders, longer procedures may be necessary.
A large study of 104 spine trauma patients who underwent MIS transmuscular pedicle screw fixation of the thoracic and lumbar spine yielded the following results. Overall, 87 percent of screws were judged to be good, 10 percent were judged to be acceptable, and 3 percent were judged to be unacceptable. Immediate surgical revision, which was always performed through MIS techniques, was necessary in nine patients for pedicle screw repositioning and in two patients for incomplete tightening of anchor bolts. In the entire patient group, two patients with an unacceptable screw position had new radicular pain that resolved completely after screw repositioning, and two patients had delayed wound healing. No patients experienced new neurological deficits.
MIS Transforaminal Lumbar Interbody Fusion
Also known as mini-open TLIF, this is a MIS technique that is performed in patients with refractory mechanical low back and radicular pain associated with spondylolisthesis, degenerative disc disease, and recurrent disc herniation. The TLIF approach may also have potential in patients with low back pain caused by postlaminectomy instability, spinal trauma, or for treating pseudoarthrosis. This procedure is contraindicated in patients who have a conjoined nerve root within the foramen, a very rare occurrence, but one that may present during surgery. The procedure is performed from the back (posterior) with the patient on his or her stomach. The major difference in the TLIF approach is that the operation is performed unilaterally, and the bone graft is inserted into the disc space through the side.
Using x-ray guidance, a 2- to 4-cm incision is made approximately 4 to 5 cm lateral to the midline. The muscles are gradually dilated and a tubular retractor inserted to allow access to the affected area of the lumbar spine. The lamina is removed to allow visualization of the nerve roots, and the facet joints may be trimmed or removed to allow more room for the nerve roots. The disc material is removed from the spine and replaced with a bone graft and structural support from a cage made of bone, titanium, carbon-fiber, or a polymer, followed by rod and screw placement. Surgeons may position small screws on the other side of the spine through a percutaneous technique to provide additional stability. The tubular retractor is removed, allowing the dilated muscles to come back together, and the incision is closed. This procedure typically takes about 2 1/2 hours to perform.
A comparison study of 20 patients who underwent endoscopic-assisted MIS TLIF with a group of patients who underwent the open PLIF procedure for single-level degenerative disease yielded the following results. In the TLIF group, there was less intraoperative blood loss, a shorter hospital stay, and postoperative narcotic use significantly decreased.
In a larger study of 49 patients (45 with both low back pain and radicular pain in the legs), and the remaining four with low back pain, there were very promising results. Eleven of the patients had previous surgeries at the same levels of the spine. Post surgery, all 45 patients with both back and leg pain reported improvement in their symptoms. The four patients with low back pain also reported a decrease in pain. At 18 months post surgery, all the patients had solid, successful fusions. The patients appeared to have less postoperative pain than with the open TLIF procedure, with narcotic pain relief medications discontinued 2-4 weeks postoperatively.
Anterior Lumbar Interbody Fusion
Although most spinal surgeries are performed using a posterior (back) approach, your surgeon may choose an anterior approach for a number of reasons, including:
- Higher rate of success.
- To avoid multiple surgeries in one area if you have already had previous spinal surgeries using a posterior (back) approach.
- To allow more direct access to the intervertebral disk.
- To have the ability to add more lordosis (curve) to your spine.
- Your recovery may be quicker.
In contrast to a posterior approach to low back surgery, when your surgeon uses an anterior approach he or she can access your spine without moving the nerves or weakening the supporting back muscles. In most cases, a vascular surgeon assists the spine surgeon with accessing the disk space.
Most interbody fusions take from 2 to 3 hours.
In the first part of the procedure, your surgeon will remove the intervertebral disk. An implant made of metal, plastic, or bone is placed between the two adjoining vertebrae. This spacer, or "cage," usually contains bone graft material. This promotes bone healing and facilitates the fusion.
After the cage is placed in the disk space, your surgeon may add stability to your spine by using a plate or screws to hold the cage in place. Before your procedure, your surgeon will talk with you about what which option will work best in your case.
OutcomeThe results of anterior lumbar interbody fusion (ALIF) surgery in the treatment of symptomatic spondylolisthesis and degenerative disc disease are generally excellent. Numerous research studies in medical journals demonstrate greater than 87-97% good or excellent results from ALIF surgery. Most patients are noted to have a significant improvement of their back pain and return to many, if not all, of their normal daily and recreational activities.
Minimally Invasive Lateral Interbody Fusion
Extreme Lateral Interbody Fusion (XLIF)
Direct Lateral Interbody Fusion (DLIF)
Direct Lateral Interbody Fusion (DLIF)
These are MIS procedures performed in patients with spinal instability caused by degenerative discs and/or facet joints that cause unnatural motion and pain, loss of height of the disc space between the vertebrae that causes pinching of the spinal nerves exiting the spinal canal, slippage of one vertebra over another, and/or changes in the normal curvature of the spine. The primary difference in these approaches is the area of the body through which the spine is accessed.
To access the anterior spine and disc space, a 5-cm incision is made on the patient’s side, usually with a second 2.5-cm incision just behind the first one. Special retractors are utilized, in addition to fluoroscopy, which provides intraoperative x-ray images of the spine. A tubular retractor or portal is passed and positioned along the lateral aspect of the vertebral bodies being operated upon. Monitoring equipment is used to determine the placement of the instruments in relationship to the spinal nerves. Disc material is removed from the spine and replaced with a bone graft, along with structural support from a cage made of bone, titanium, carbon-fiber, or a polymer. This provides extra stability and helps the bone heal. Sometimes, surgeons will position small screws in the spine posteriorly through an additional procedure. This procedure is limited to one or two levels, and only vertebra that can be clearly accessed from the side of the body can be operated on. This procedure typically takes about 1 to 1 1/2 hours to perform.
Because this is a fairly new procedure, there is very little long-term outcome data available. In general, there is very little blood loss with this procedure. Many patients are ambulatory within a few hours and discharged from the hospital the next day. Patients are often back to work within a few weeks.