The ABCs of Spinal Fusion Surgery

Spinal fusion surgery is any surgery in which two vertebrae are joined or fused together. This surgery can take place anywhere along the spine and the joining or fusion can be accomplished in different ways. Spinal surgeons often talk about spinal fusion surgeries in terms of acronyms that describe these concepts.

Interbody Fusion

Many fusion surgeries are accomplished by using an instrument or “interbody device” to help join the vertebrae. This is specially designed hardware that is implanted into the body. Bone graft material is then packed around the interbody device to help stimulate the fusion process.

Surgical Approach

Depending on the portions of the spine to be fused, the surgeon may approach the spine from the front (anterior) or the back (posterior). An anterior approach means that the surgeon will make an incision in the abdomen to reach the “front side” of the spine. A posterior approach means that the surgeon will make an incision in your back. A surgeon can also approach the spine from the side (lateral).

Area of the Spine

The spine is divided into three main regions: the cervical spine (neck area), the thoracic area (the rib area), and the lumbar region (lower back). Fusion surgery can occur anywhere along the spine, but is most common in the lumbar region.


An ALIF is an anterior lumbar interbody fusion, which means a device will be implanted in the lower back to fuse two vertebrae and the surgeon will make the incision to reach the back in the abdominal region.


XLIF stands for “extreme lateral interbody fusion” and DLIF stands for “direct lateral interbody fusion.” In these procedures, the surgeon makes an incision in the patient’s side so that muscles and tendons are disturbed as little as possible.


PLIF (posterior lumbar interbody fusion) and TLIF (transforaminal lumbar interbody fusion) are type of fusion that is done by removing the disc material from the back incision. The surgeon approaches the spine from the back and places an interbody device and bone graft after disc has been removed.


The posterolateral fusion (PLF) is a very well-known spinal fusion technique and one that does not require any hardware or interbody device. The surgeon makes an incision in the back and then places bone graft along the area to be fused in an area alongside the spine nicknamed “the gutter.” This area gets a rich supply of blood and nutrients, which helps stimulate bone growth and promote the fusion.

The Right Spinal Fusion for You

The University Spine Center will discuss the most appropriate spinal fusion procedure for you. Some of these procedures can be done as minimally invasive surgery, others are major surgery (“open” procedures) and some can be done as “mini-open” procedures. The decision as to which procedure is appropriate for you depends on your condition, the type of spinal disorder you have, your medical history, and the surgeon’s judgment.