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Department of Orthopedics

Department of Orthopedics

Common Procedures

CU Orthopaedics Spine Division

Minimally Invasive Spine Surgery

For many years, traditional spinal surgery has usually involved large incisions up and down the middle of the back, and spreading apart (or retracting) the back muscles to access the spine. This is commonly referred to as an open technique. The advantage of open techniques is that it provides the surgeon with easy access to the spine. The downside of open spine surgery is that retraction damages the back muscles and can cause significant post-operative pain and extended recovery.

While in many instances open techniques are preferred, more and more conditions are now surgically treated using new minimally invasive techniques. Minimally invasive spine surgery allows the surgeon to make smaller incisions in the skin and avoid large muscle retraction. The surgeon uses a scope inserted through a small incision. A tiny video camera and light are connected to the scope and send images from inside the body to a screen in the operating room. Small tubes are then inserted through other small incisions and surgical instruments are inserted through these tubes and used to perform the procedure.

Advantages of minimally invasive techniques

Minimally invasive spine surgery generally results in the same surgical outcome as with more traditional techniques. However, there are a number of advantages to minimally invasive techniques, including:

  • Reduced operative times.
  • Less soft tissue and muscle damage.
  • Reduced blood loss.
  • Quicker recovery.
  • Shorter hospital stay.
  • Less noticeable and cosmetically more pleasing scarring.

These minimally invasive techniques can be used for almost all of the spinal surgeries described below; however, the techniques must match the patient’s needs and sufficient experience with each technique is required for it to be successful.


A disc herniation, commonly known as a slipped disc is sometimes required when the jelly-like disc material is squeezed out from between the vertebral bodies. This material may irritate a nerve root in the back or neck and require removal for treatment. Several methods of discectomy are available and may be utilized based on the type of disc herniation.

In the past a large open incision was required for almost all spine procedures. Now large open incisions are utilized only when a discectomy is performed in combination with a larger procedure.

Microdiscectomy surgery for a herniated lumbar disc is traditionally performed through a one to two-inch incision. The muscle must is pulled aside and the opening between the bones is widened to allow access to the spinal canal. The herniated disc material is then removed.

Endoscopic microdiscectomy utilizes specialized retractors and x-rays in the operating room to make a smaller incision through which the spine is approached. This allows the surgeon to use both the camera and the microscope to visualize the spine and spinal canal. Using specialized instruments, the surgeon can safely remove the herniated disc material.

The benefit of this procedure lies in the reduction of local trauma. Specifically, this means that less of the muscles, ligaments, and soft tissues are disrupted to perform the procedure. This translates into less pain after surgery and an enhanced rate of recovery. This technique can often be done on an outpatient basis and many patients can return to work in just a few days.

This technique is only appropriate for certain types of disc herniations and is not as appropriate for revision surgeries.

Disc Replacement Surgery

When disc degeneration advances to cause chronic back or neck pain, the disc may require removal for treatment. The typical treatment after removal of a disc has been fusion surgery. This treatment achieves very good results; however, there is increased risk for degeneration at an adjacent spinal level and there is some reduction in mobility.

Recent technological advances have allowed us to replace discs, when appropriate, instead of fusing the spine. This treatment provides pain relief while maintaining the mobility of the spine. Though the technology is new, our experiences with the FDA trials have been excellent with an extremely high rate of patient satisfaction.

Spinal Decompression

Spinal stenosis is often a problem of the aging spine. As arthritis of the spine increases, the spinal canal and foramina may become narrowed allowing less room for the spinal cord and nerve roots. This often leads to back and leg pain as well as weakness. These typically result in decreased walking tolerance. The stenotic spine can be treated with conservative measures such as therapy and injections, but when these fail, decompression may be required. Spinal decompression surgery involves removing the arthritic bone and soft tissues that compress the spinal canal and nerve roots. Recovery is relatively quick with high patient satisfaction.

If stenosis is combined with instability of the spine, both decompression and stabilization with instrumentation is required. This has typically been spinal fusion; however, newer techniques of dynamic stabilization such as dynesis are available that stabilize the spine without requiring fusion. This results in a shorter recovery and better mobility.

Vertebroplasty and Kyphoplasty

Patients with osteoporosis are often at risk of spinal compression fractures. These fractures can be very painful and may lead to kyphosis (hunching over) of the spine. Though most of these fractures heal over time, some continue to be painful. Vertebroplasty and kyphoplasty refer to two methods of injecting bone cement through a small tube into the fracture site. This provides support for the fracture and significantly reduces pain. The procedure is often done with the patient awake and patients return home the same or next day.

Spine Fusion Surgery

In some instances, there is either too much degeneration or too much instability for disc replacement and spine fusion is required. Spinal fusion surgery is a common treatment for such spinal disorders as spondylolisthesis, scoliosis, severe disc degeneration, or spinal fractures. Again multiple methods for fusion are available and should be tailored appropriately based on the patient’s condition.


New and evolving technologies now allow us to perform lumbar interbody fusion surgery via the micro-open or endoscopic approach. The micro-open approach can be performed over multiple levels while the endoscopic approach is most appropriate for spine conditions affecting one level. The endoscopic approach to lumbar interbody fusion can be performed through several small punctures in the skin. The micro-open approach requires a small incision that is considerably smaller and less traumatic than the traditional open approach. In both cases, pedicle screw instrumentation is often used and can be performed by placing the screws through small incisions made through the skin.

The endoscopic or mini-open approach can reduce the patient's hospital stay. Postoperative pain is dramatically reduced and overall function is dramatically improved. Return to work and play can be greatly accelerated by utilizing these techniques.


Anterior Lumbar Interbody Fusion involves fusing the spine across the disc space from the front. The surgical access for this procedure is traditionally done through an incision in the left lower abdominal area. This incision may involve cutting through and later repairing, the muscles in the lower abdomen. At the University of Colorado’s Orthopaedic’s Department Spine Division, a mini open approach is available that preserves the muscles and allows access to the front of the spine through a very small incision. This approach maintains abdominal muscle strength and function and is oftentimes used to fusion a few levels.

Many levels may need to be fused from the front of the spine when performing surgery for complex problems such as scoliosis. Unfortunately, the mini open technique does not allow access to multiple levels. Therefore, a more traditional approach may be needed to perform anterior fusion for scoliosis.


PLIF stands for Posterior Lumbar Interbody Fusion. In this fusion technique, the vertebrae are reached through an incision in the patient's back (posterior).

The PLIF procedure involves three basic steps:
1. Pre-operative planning and templating. Before the surgery, the surgeon uses MRI and/or CAT scans to determine the size of implant(s) the patient needs.

2. Preparing the disc space. Depending on the number of levels to be fused, a 3-6 inch incision is made in the patient's back and the spinal muscles are retracted (or separated) to allow access to the vertebral disc. The surgeon then carefully removes the lamina (laminectomy) to be able to see and access the nerve roots. The facet joints, which lie directly over the nerve roots, may be trimmed to allow more room for the nerve roots. The surgeon then removes some or all of the affected disc and surrounding tissue.

3. Implants are then inserted. Once the disc space is prepared, a bone graft, allograft or BMP with a cage, is inserted into the disc space to promote fusion between the vertebrae. Additional instrumentation (such as rods or screws) may also be used at this time to further stabilize the spine.


TLIF stands for Transforaminal Lumbar Interbody Fusion. This surgery is a refinement of the PLIF procedure and has recently gained popularity as a surgical treatment for conditions affecting the lumbar spine. The TLIF technique involves approaching the spine in a similar manner as the PLIF approach but more from the side of the spinal canal through a midline incision in the patient's back. This approach minimizes the nerve manipulation required to access the vertebrae, discs and nerves.

As with PLIF and ALIF, disc material is removed from the spine and replaced with bone graft inserted into the disc space(along with cages, screws, or rods if necessary). The instrumentation helps facilitate fusion while adding strength and stability to the spine.


Recovery time is different for every patient, however, most patients are up and walking by the end of the first day after surgery. Most patients can expect to stay in the hospital for 3-5 days depending on their condition. Once released from the hospital, patients who have undergone a PLIF, ALIF, or TLIF procedure are given a prescription for pain medications to be taken if needed, as well as a detailed post-operative physical therapy/exercise plan to help ease recovery and return to a healthy life.

Spine Fractures

Fractures of the spine can be quite complex and often require surgical treatment for both decompression of the spinal cord and for stabilization of the spine. Every fracture is different and individualized treatment is carefully planned according to each patients needs. Brace treatment is often sufficient for most fractures; however, spinal canal compromise and spinal instability may require surgical treatment. Surgery may require anterior spine decompression, posterior stabilization or both.

Spine Infections

Spine infections may present from a variety of causes. Infections often affect the bones, discs, nerves, or all three. Though antibiotics and rest may be enough for treatment of early infections, surgery is required for those that progress. Typically this requires removal of the infected bones and disc spaces and stabilization of the spine to allow healing.

Spine Tumors

Spine tumors may originate in the spine or may be metastatic to the spine. These complex problems require a multidisciplinary approach including oncologists, radiation treatment specialists, and surgeons. Spinal surgery includes decompression of the spine as well as stabilization. Treatment is individualized based on the type of tumor and involvement of the spine.