Quick Facts
Possible Symptoms
- Leg pain, numbness, and/or weakness
- Back pain, especially with movement
- Bowel or bladder incontinence
Typical X-Ray Findings
- Spondylolisthesis, or slippage of one vertebral body upon another (MRI, CT myelogram).
- Disc and endplate changes suggesting excess “wear and tear” (MRI, CT myelogram).
- Excess movement of one vertebral body upon another when bending forward or backward (Flexion and extension x-rays)
Average Procedure Time
- 2-6 hours, depending on number of levels
Average Recovery Time
- Home in 2-4 days
- Off work 6-8 weeks, depending on duties
Postperative Limitations
- No bending, twisting, lifting, or strenuous exercises (8 weeks)
- No driving while on narcotics
The Procedure
Instrumentation with screws and rods is done to stabilize the spine in an area that may be unstable from degeneration or a fracture. Instrumentation is always performed in conjunction with at least one fusion procedures such as a Posterolateral Lumbar Fusion (PLF), Anterior Lumbar Interbody Fusion (ALIF), Posterior Lumbar Interbody Fusion (PLIF), or Extreme Lateral Interbody Fusion (XLIF).
While instrumentation with screws and rods used to involve rather large incisions, newer technologies allow us to do this minimally invasively, through natural muscle planes. Minimally invasive technology allows for quicker recovery times and a dramatically decreased rate of infection, since tissue disruption is minimal compared to that which is necessary with traditional approaches.
Traditional Instrumentation vs. Minimally Invasive Instrumentation
The Old Way
An incision is made in the midline. Muscle is burned and then peeled off of enough of the spine in order to expose the bone that will accommodate the screws. Spiked retractor blades (pink lines) hold the muscle off of the bone while screws are placed. At the end of the procedure, even though sutures are used to sew the damaged muscle back together, a significant amount of “dead space” (shown in pink), remains. Fluid tends to accumulate in this space and can become infected. [/one_half]
The New Way
Two incisions measuring about 1.5 inches each are made 2 inches on each side of the midline. Muscle bundles are separated bluntly (with a gloved finger) through natural tissue planes (green lines) in order to expose the bone that will accept the screws. Screws are advanced using xray guidance and electrical monitoring to make sure no nerves are contacted. After the insertion of the screws and rods, the the muscle falls back into place, with minimal dead space, and does not even need to be sutured!
The Old Way
A midline incision is made and muscle is retracted away from the midline using large clawed retractors for several hours while bone is removed and screws and rods are placed under direct visualization.
The New Way
Incisions are made 2 inches off of midline, and screw towers attached to screws are placed using image guidance with live xrays or CT scanning through natural tissue planes. Muscle is only minimally retracted. Bone is removed in corridors created between the screws. Afterwards, rods are placed through the screw towers, which are then detached from the screws.
The Old Way
The wound must be closed in multiple layers in order to eliminate the “dead space” that results from retracting the muscle during the duration of the procedure. A lengthy midline incision is generally closed with nylon sutures.
The New Way
Upon removal of the screw towers, the muscle falls back into place, and no sutures need to be placed into them. Only the tough fascia covering the muscles is closed. The small skin incisions are closed with reabsorbable sutures and tape strips.