When there is settling of one vertebra over the other due to disc degeneration, patients may develop back pain or unstable spine (spondylolisthesis) from abnormal stresses that develop in this segment of the spine. Furthermore, as the bones settle, the nerves that exit between these bones can get pinched resulting in a sciatica type pain. In this scenario placing an implant between the two settled bones to gain the normal height can help with the back pain, instability and/or the leg pain. This can now be accomplished through a very small incision in the back of the spine, using live x-rays and the microscope in the operating room (minimally-invasive surgery). Screws used to hold the spine together until the bones heal together can also be placed using very small incisions. Traditionally this type of surgery required a long incision and stripping the muscles off the spine, which resulted in more postoperative pain and permanent damage to the muscles and a longer recovery. With the use of minimally-invasive techniques, the muscle injury is minimized and patients can return to their routine activities much sooner than they were otherwise able to.

Posterior Lumbar Interbody Fusion (PLIF) is a common surgical technique used to treat conditions such as spinal instability, slippage, or compression of the nerves in combination. In this procedure, bone graft, or a bone graft substitute, is inserted between vertebral bodies to fuse them and create a stronger and more stable spine. At the same time, the spinal nerves and spinal canal are freed by removing bone spurs and herniated discs at the same time. The bone graft is inserted into the disc space from behind. In addition, instrumentation with screws and rods are used to hold the spine steady as the bone heals.

In recent years, many surgeons have begun to use a transforaminal lumbar interbody fusion (TLIF) procedure in preference to a PLIF. A TLIF can accomplish the same goals of decompressing the nerves and stablizing the spine. In a TLIF procedure, however, the surgeon inserts the bone graft into the disc space from an angle on only one side. This results in less manipulation of the nerve roots as compared to a PLIF, and also reduces the surgical time, blood loss and tissue trauma to the patient.

Traditionally, TLIF has been performed as an "open" technique, which requires making a larger incision along the middle of the back. Through this incision, the surgeon then cuts away, or retracts, spinal muscles and tissue to access the vertebrae and disc space. The cutting and retracting of muscle and tissue is part of the reason that after the surgery, patients are faced with a long recovery period of several weeks or months.

Today, the minimally-invasive TLIF technique is proving to be an effective alternative to "open" fusion surgery. In a minimally-invasive TLIF, the surgeon inserts a small tube through the skin until it "docks" on the spine. Using special surgical instruments the surgeon then does the entire TLIF procedure through the tube. Working through the small portal, the minimally-invasive technique greatly reduces the amount of muscle and tissue that is cut or retracted. Blood loss is dramatically reduced. These minimally-invasive benefits also lead to a shorter hospital stay and more rapid patient recovery time. In several studies conducted at UCLA, we have been able to demonstrate a 5- 10-fold reduction in blood loss, 20-40 percent shorter surgical times, a 30-40 percent decrease in postoperative narcotic use, a 30 percent shorter hospitalization time and a more rapid overall postoperative recovery with regard to pain and the patient's ability to return to work. Ultimately, the same study has also demonstrated that the overall succesful fusion and functional outcomes at 2 years are the same as open, traditional TLIF or PLIF.