BONE GRAFTS in SPINE SURGERY
Spinal fusion is one of the most common surgeries done in the neck or back. The basic idea is to fuse together painful bones in the spine so that they heal into a single, solid bone. In order for bones to fuse or heal together, additional bone is needed. This additional bone is called a bone graft.
Many bone graft options are used today. They are often are combined together. The graft that is best for your problem will depend upon which section of your spine needs to be fused, your age, and your general health (AAOS, 2015).
There are a number of considerations to evaluate when deciding which type of bone graft options to use. The main factors to be taken into account include:
- Type of spinal fusion (e.g. ALIF, PLIF, posterolateral gutter)
- The number of levels of the spine involved
- Location of fusion – (neck fusion or lumbar fusion)
- Patient risk factors for non-fusion (e.g. if patient is obese, a smoker, poor bone quality)
- Surgeon experience and preference.
To date, using the patient’s own bone is considered the gold standard. However, this is not the best option for all patients.
In an effort to reduce the surgical risks and possible complications with using the patient’s own bone, and to enhance rates of fusion, the spine medicine community is focusing resources on developing better options.
When a spinal fusion is to be performed in an attempt to restore stability of the spine, one needs to achieve a solid biological union between at least two vertebrae. Typically, in order for this to occur, bone material is placed adjacent to the vertebrae to be fused. This bone material is referred to as “bone graft.” Traditionally, this bone graft material is harvested from a separate incision through the iliac crest (superficial part of the pelvis).
Currently, there are many alternatives to using one’s own iliac crest bone as bone graft material.
The surgical implantation procedure is performed through an incision in the abdomen (similar to an anterior lumbar interbody fusion).
With this approach, the organs and blood vessels must be moved to the side. This allows your surgeon to access the spine without moving the nerves.
Usually, a vascular surgeon assists the orthopaedic surgeon with opening and exposing the disc space. Most surgeries take about 2 to 3 hours.
The disc replacement device may comprise the nucleus (center) of the disc while leaving the annulus (outer ring) in place, although this technology is still in an investigative stage.
In most cases, total artificial disc replacements substitute the annulus and nucleus with a mechanical device that will simulate spinal function.
There are a number of different disc designs. Each is unique in its own way, but all maintain a similar goal: to reproduce the size and function of a normal intervertebral disc.
Some of the discs are made of metal, while others are a combination metal and plastic, similar to joint replacements in the knee and hip. Materials used include medical grade plastic (polyethylene) and medical grade cobalt chromium or titanium alloy.