Question:
In patients with painful osteoporotic vertebral fractures, what is the 6-month effectiveness and safety of vertebroplasty?
Design:
Randomized (allocation concealed), blinded (patients, investigators, and outcome assessors) controlled trial with 6-month follow-up.
Setting:
4 university hospitals in Victoria, Australia.
Patients:
78 patients with back pain for =12 months, 1 or 2 recent vertebral fractures, and edema or a fracture line, or both, within the vertebral body were enrolled. Exclusion criteria included >2 recent vertebral fractures, spinal cancer, neurologic complications, vertebral collapse of >90%, posterior wall destruction, impingement on the spinal cord, and previous vertebroplasty. Complete data were available at 6 months for 71 patients (91%).
Intervention:
Patients were allocated to vertebroplasty (n = 38) or a sham procedure (n = 40). For vertebroplasty, a 25-gauge needle was used to infiltrate the skin overlying the pedicle, and a 23-gauge needle was used to infiltrate the periosteum of the posterior lamina. A 13-gauge needle was placed posterolaterally relative to the eye of the pedicle and then was guided into the anterior two-thirds of the fractured vertebral body into which an average of 2.8 mL of polymethylmethacrylate (PMMA) was injected. The sham procedure was identical to the vertebroplasty procedure up to the insertion of the 13-gauge needle to rest on the lamina. The vertebral body was gently tapped, and the smell of PMMA permeated the room.
Main outcome measures:
The primary outcome was the pain score at 3 months on a scale of 1 to 10 (with 0 indicating no pain and 10, maximum imaginable pain; 1.5 was the minimal clinically important difference). Secondary outcomes included quality of life (QOL) measured with use of the 41-item Quality of Life Questionnaire of the European Foundation for Osteoporosis (QUALEFFO) (a scale of 1 to 100, with lower scores indicating better QOL), the Assessment of Quality of Life questionnaire (a scale of 0 to 1, with 1 indicating perfect health), and the European Quality of Life-5 Dimensions scale (a scale of 0 to 1, with 1 indicating perfect health). Other secondary outcomes included scores for pain at rest and at night, and the score on a modified 23-item version of the Roland-Morris Disability Questionnaire (a scale of 0 to 23, with higher scores indicating worse physical functioning).
Main results:
Analysis was by intention to treat. The study had 80% power to show at least a 2.5-unit difference in pain between vertebroplasty and placebo. Overall pain scores at 3 months were not significantly different between patients in the vertebroplasty and placebo groups (Table). QOL measures and physical functioning were also not different between the groups at any follow-up evaluation (Table), except for QUALEFFO scores that favored the placebo group at 1 week.
Conclusion:
In patients with painful osteoporotic vertebral fractures, vertebroplasty conferred no short-term benefit compared with a sham procedure.
Vertebral compression fractures cause pain, disability, and increased mortality. Treatment options range from medications and bracing to minimally invasive procedures such as vertebroplasty. Buchbinder and colleagues report a sham control blinded, multicenter study with 6-month follow-up that revealed no benefit for vertebroplasty.
While other studies have noted pain reduction following vertebroplasty and/or kyphoplasty, they were less well designed and did not include a sham control group. While the sample was only 71, this study was powered to detect a difference of 2.5 in pain scores. The authors noted the possibility of selection bias as only 70% of potentially eligible participants were enrolled. However, of the 219 truly eligible patients, 141 (64%) declined to participate. These 141 patients would have been of interest to follow as well.
The average volume of PMMA injected was 2.8 mL through only one pedicle, whereas for balloon kyphoplasty both pedicles are used for injection. While the effect of volume in many studies has not been shown to affect outcome, one study showed that cement volume may affect the biomechanical behavior of cadaver vertebral bodies1.
While long-term follow-up will be required to provide optimal information regarding both clinical successes and adverse risks, on the basis of this trial we should be hesitant to use vertebroplasty to treat patients with vertebral compression fractures.
Reference
Belkoff
SM;
Mathis
JM;
Jasper
LE;
Deramond
H. The biomechanics of vertebroplasty. The effect of cement volume on mechanical behavior. Spine (Phila Pa 1976).
2001;26:1537-41.[PubMed] [CrossRef]