What is a non-union? F or most doctors it means two or more bones that were supposed to heal
together but did not. To give an example, sometimes broken leg bones do not heal.
Surgery may be necessary to unite the bone edges together. Non-unions can happen to any bone,
although for most healthy people the body usually can mend the broken bones without surgery.
For people who have certain spinal conditions a spinal fusion operation may have been performed.
Usually the fusion is recommended because your surgeon thinks you have an unstable spine,
or to correct a spine curvature problem. While spinal fusion surgery has its risks,
in the united states it's a very common procedure. In this discussion I will not discuss the risks or
benefits of spinal fusion. Instead, let's focus on what is a non-union for a spinal fusion.
Contemporary spine fusion techniques utilize metallic plates, screws, or rods to hold the
bones in place. Sometimes it includes a cage device to provide added stability and surface
to promote fusion. The body mobilizes the specific bone forming cells to create a
bony bridge to unite the two or more bones. To promote healing the bone surfaces are scratched
to cause some bleeding. This effectively creates a similar situation as a broken bone.
The body reacts by trying to heal this break. To aid in the fusion, or uniting of the bones,
bone tissue is obtained from the hip crest. This material is like a putty that helps unite the
broken bones. The hope is that the bone heals together over time thus achieving a fusion.
Unfortunately, the non-union rates of fusion can be significant for certain situations. Medical
risk factors from non-union include smoking history, diabetes, osteoporosis, and steroid use.
Surgical factors include multiple levels of fusion, posterior only approach, and lumbar
location. Non-union is associated with poorer outcomes and more pain after surgery. So how do
we determine if there is a non-union? The most obvious sign is gaps without healing on x-rays.
If there are concerns for non-unions, x-rays obtained while flexing and extending your spine
can also determine a non-union. Unfortunately, because this motion can be painful, a person
may not be able to give full effort, inflection, and extension. These x-ray views may not always
show the non-union. Right now most will use a thin cut CT Scan to diagnose a non-union. Halos are
caused by compressing the bones around the metal because of the motion caused by lack of union.
Sometimes there are even broken screws or rods, that should cause suspicion
of a non-union. So what should you do if you have a non-union? Well that depends, sometimes the best
option is to do nothing if you're feeling fine. In other circumstances the lack of fusion causes
the metallic screws and rods to dig in the bones causing the so-called "Windshield Wiper Effect".
Because this puts important structures such as nerves or blood vessels at risk,
the hardware should be removed and, if necessary, another fusion attempted.
It is a potentially difficult decision for both the surgeon and the patient.
If you have these concerns, make sure to obtain a few opinions.
If you're contemplating a fusion operation please be aware of the potential complications.
Your surgeon will do their best to create the best fusion environment for your spine.
Still, it's a possibility, and if you have the risk factors mentioned above,
please weigh them before deciding to have a fusion operation. Thanks for watching.
you