Surgeons Compare Techniques for Kyphoplasty to Treat Vertebral Compression Fractures
Patients experiencing pain and loss disability from vertebral compression fractures (VCFs) may find relief with a procedure called balloon kyphoplasty. The procedure is designed to restore height of the fractured and collapsed vertebra (spinal bone).
Compression fractures are the most common type of fracture affecting the spine.
Multiple-level vertebral compression fractures are commonly the result of osteoporosis. Spine bones weakened from osteoporosis (brittle bones) may become unable to support normal stress and pressure.
As a result, something as simple as coughing, twisting, or lifting can cause a vertebra to fracture. In fact, a simple action like reaching down to pull on a pair of socks can cause a weakened vertebra to crack or fracture. The front of the vertebra (the part closest to the front of the body) crumbles, causing the round vertebral body to become wedge-shaped. This angles the spine forward, producing a hunch-backed appearance, called kyphosis.
That's where a balloon kyphoplasty comes in. Two long needles are inserted through one or both sides of the spinal column into the fractured vertebral body. These needles guide the surgeon while drilling two holes into the vertebral body. The surgeon uses a fluoroscope (special 3-D real-time X-rays) to make sure the needles and drill holes are placed in the right spot.
The surgeon then slides a hollow tube with a deflated balloon on the end through each drill hole. Inflating the balloons restores the height of the vertebral body and corrects the kyphosis deformity.
Before the procedure is complete, the surgeon injects bone cement into the hollow space formed by the balloon. The cement is injected a little bit at a time until the cavity is filled. They try to keep most of the cement in the front three-fourths of the vertebral body. This fixes the bone in its corrected size and position and supports the front part that has collapsed the most.
This procedure halts severe pain and strengthens the fractured bone. However, it also gives the advantage of improving some or all of the lost height in the vertebral body, helping prevent or correct kyphosis.
In this study, surgeons compared results when the balloon kyphoplasty procedure was done from one side (unilateral) versus inserting needles from both sides (bilateral) of the vertebral bone.
Safety is always an issue with any spinal procedure. Inserting needles from both sides of the spine has the potential to create more problems and complications compared with a unilateral approach. Surgeons want a safe procedure that is also effective. Can a balloon kyphoplasty for multiple-level fractures be done both safely and effectively using the unilateral technique? Let's find out.
For the record, multiple-level fractures in this study referred to two or more painful vertebral compression fractures (VCFs) in each patient. The VCFs were in the thoracic or lumbar spine of 49 patients. There were a total of 114 VCFs (all caused by osteoporosis). Patients ranged in age from 52 to 91 years old.
One half of the group had a unilateral balloon kyphoplasty. The other half had a bilateral approach. Details of how the procedures were done are described by the author for surgeons who perform this technique or who are interested for other reasons.
The idea of doing the procedure from both sides is that this would provide a more even lift of the collapsed vertebra. Another potential advantage of the bilateral injection is to create a large cavity to inject as much cement as possible.
On the other hand, a unilateral approach takes less time. This advantage translates into money that can be saved with shorter operative procedures. With less time required to complete the kyphoplasty, the patient is exposed to less radiation from X-rays (fluoroscopy).
A unilateral approach reduces the risk of puncturing nerves or blood vessels with the needles. Inserting one instead of two needles also reduces the chances of fracturing a bone unintentionally.
Results were measured before and after surgery using patient surveys of pain levels, disability, and general health. X-rays were used to look at before and after height of the vertebrae and the angle of kyphosis (forward bent spinal curve).
Everyone was followed for at least two years. This type of follow-up provides an idea of mid- to long-term results (i.e., how long and how well the benefits last). Both groups did equally well! Patients were relieved of pain and improved back function. Those benefits were still present two years later.
A few of the patients did end up having more compression fractures but these were at new levels and not previously treated by kyphoplasty. The most common "problem" that occurred was leaking of the cement into the disc or vein alongside the vertebra.
The word problem is in quotes because this isn't supposed to happen and it is technically considered a complication of the procedure. But none of the patients experienced any real problems (pain, sensory changes) because of it. If X-rays had not been taken, no one would have even known this had happened.
The authors conclude that unilateral balloon kyphoplasty for multi-level vertebral compression fractures are both safe and effective. Performing this procedure from one side instead of injecting cement through needles inserted on both sides has many advantages. Strength of vertebral repair and stiffness are not compromised in any way. All corrections made through this procedure are maintained for at least two years.
Reference: Liang Chen, MD, PhD, et al. Unilateral Versus Bilateral Balloon Kyphoplasty for Multilevel Osteoporotic Vertebral Compression Fractures. In Spine. April 1, 2011. Vol. 36. No. 7. Pp. 534-540.