Sixty-Year Review of Lumbar Fusion

In this article, surgeons from several large U.S. orthopedic departments take a look back over the last 60 years of spinal surgery for lumbar fusion. What started out as a simple posterior fusion of the vertebrae bones for a wide variety of problems has been streamlined to a procedure called interbody fusion used for lumbar instability.

Techniques and surgical approaches (anterior, posterior, transforaminal, or combination) have changed over the years. Interbody (circumferential) fusion has become mainstream. The introduction of a minimally invasive method has minimized surgical trauma and reduced hospital time, blood loss, and complications.

The authors provide a historical review of each type of fusion (e.g., open versus minimally invasive, different ways to do an interbody fusion) and type of complications with each. Technical challenges and effectiveness of each procedure are also reviewed.

Newer approaches to fusion such as the XLIF, ALIF, and AxiaLIF are discussed. XLIF is actually a trade name that refers to a direct lateral lumbar interbody fusion. ALIF stands for anterior lumbar interbody fusion. In this operation, the surgeon reaches the spine through the abdomen. The axial lumbar interbody fusion (AxiaLIF) is used to fuse the last lumbar vertebra (L5) to the sacrum (S1).

A very helpful table is included that summarizes the methods of interbody fusion and compares the advantages and disadvantages of each one. Some of the techniques developed more recently don’t have enough studies done yet to come to any conclusions. What they have been able to tell so far can be summed up as follows:

  • Transforaminal and posterior interbody fusions seem to have about the same results in terms of stabilizing the spine. The transforaminal technique has fewer complications and less blood loss.
  • Anterior interbody fusion can be done with a mini-open incision or laparoscopically. Outcomes are the same in terms of spinal stabilization but the laparoscopic technique has more problems and takes longer.
  • Minimally invasive is superior to the mini-open incision when measured by amount of blood loss, length of hospital stay, intensity of back pain after surgery, and time in the operating room.
  • Despite advantages of some surgical approaches over others, the results are fairly comparable with high rates of fusion and good clinical results (e.g., pain relief, improved function).

    After reviewing many studies on lumbar fusion from 1950 to 2010, it is clear that more level one studies are needed to directly compare different fusion methods. There is not enough evidence at this point to say one approach is superior to the others. Tissue engineering and tissue regeneration may eventually replace surgical fusion. Such advanced biologic techniques could eliminate nerve or other soft tissue damage caused by currently used surgical methods.