Vertebroplasty for fractures with clefts may be an effective, but not superior treatment

Percutaneous vertebroplasty remains a viable option for patients with osteoporotic compression fractures with intravertebral clefts, but may not be a superior treatment because of its delayed treatment benefits, according to a recent presentation.

“The intervertebral cleft is generally believed to be a representation of an avascular necrosis and resulting intravertebral pseudoarthrosis of the vertebral body,” Marc J. Nieuwenhuijse, MD, said at the 12th EFORT Congress 2011. “Patients with osteoporotic vertebral compression fractures with intravertebral clefts are therefore thought to represent specific subgroups who present themselves with intense pain, exhibit higher fracture mobility and who experience considerable benefit from vertebroplasty.”

Nieuwenhuijse and his team studied whether patients with intravertebral clefts benefit from vertebroplasty and whether clefts prevent cement leakage because of their cavitational nature.

“Current literature is inconclusive regarding these aspects,” Nieuwenhuijse said.

Pictured is an intravertebral cleft on radiography (left) and on MRI (right). Images: Nieuwenhuijse MJ

Clefts vs. no clefts

Nieuwenhuijse and colleagues compared patients with and without vertebral clefts who underwent vertebroplasty for clinical outcomes, frequency of new vertebral fractures and rate of cement leakage 1 year after vertebroplasty. To assess the influence of clefts, the team also compared patients who had one vertebral level treated.

The team prospectively studied 102 patients with 197 osteoporotic vertebral compression fractures. The patients had unrelieved focal back pain after 2 months of conservative therapy, which corresponded to the location of a fracture on radiography and showed bone marrow edema on MRI. The researchers measured outcomes using the 0 to 10 Pain Intensity Numerical Scale for back pain and the SF-36 quality of life questionnaire before percutaneous vertebroplasty and at 7 days, 1 month, 3 months and 12 months postoperatively. They assessed each patient for cement leakage on postoperative CT and for possible new fractures at 6 weeks and 52 weeks and on indication.

“Cement leakage was defined as the presence of any extravertebral cement,” Nieuwenhuijse said.

Influence of clefts

The team identified 42 clefts in 41 patients. They found clefts were most commonly at the thoracolumbar junction and in severely collapsed vertebral fractures.

Patients with clefts showed less interdigitation of bone cement than patients without clefts. Patients with clefts also experienced decreased back pain and increased physical functioning after vertebroplasty.

“Although this improvement in patients with clefts was smaller than patients without clefts, this difference was not statistically significant after correction for other relevant variables like fracture severity and appearance of new vertebral fractures,” Nieuwenhuijse said.

This difference was more pronounced — and significant — in patients who underwent vertebroplasty at one level. Patients who underwent one level of vertebroplasty showed initial improvement, but relapsed 1 month postoperatively. During the first postoperative year, patients who underwent one level of vertebroplasty and had a cleft, showed a smaller and more gradual treatment effect compared to patients without clefts. However, 1 year postoperatively, both groups showed similar treatment effects. Both the time between occurrence of new fractures and adjacent level fractures was similar in patients with or without clefts.

The researchers discovered cement leakage in 145 of 197 vertebral levels.

“After correction for fracture severity, cement viscosity and fracture level, the cleft was not found to be associated with the occurrence of venous cement leakage,” Nieuwenhuijse said. “However, the cleft was identified as a strong risk factor for occurrence of cortical cement leakage. Cortical cement leakage consists for 95% of intradiscal cement leakage.”

Comparison to the literature

Compared with other studies, this study used “an extensive identification procedures of an intravertebral cleft on multiple imaging modalities by three experienced examiners” and treated patients only with “long standing painful osteoporotic vetebral compression fractures with a mean time of 6 months since onset of symptoms,” according to Nieuwenhuijse.

The researchers hypothesize that the delayed benefit of vertebroplasty in patients with clefts may be caused by its association with cement fracture or refracture of treated levels.

“However, we did not encounter this in our study,” Nieuwenhuijse said.

Another hypothesis is that patients with clefts have higher residual mobility resulting in less stabilization because of less interdigitation of bone cement with the vertebral body, according to Nieuwenhuijse.

“Patients with long-standing painful osteoporotic vertebral compression fractures with intravertebral clefts benefit from vertebroplasty,” Nieuwenhuijse concluded. “However, compared to patients without intravertebral clefts, the treatment effect may not be superior and may be delayed. Furthermore, the cleft is a risk factor for cortical leaking and this is relevant since cortical leakage may be associated with the indication of new adjacent level vertebral fractures.” – by Renee Blisard

Reference:

• Nieuwenhuijse M, Van Rijswijk C, Van Erkel A, et al. Patients with osteoporotic vertebral compression fractures with intravertebral clefts do not constitute a superior treatment indication for percutaneous vertebroplasty. Paper #1213. Presented at the 12th EFORT Congress 2011. June 1-4. Copenhagen, Denmark.

• Marc J. Nieuwenhuijse, MD, can be reached at the Department of Orthopedic Surgery and Radiology, Leiden University Medical Center, Building 1, Room J11-R, Albinusdreef 2, 2333 ZA, Leiden, The Netherlands; 31-71-5263606; email: m.j.nieuwenhuijse@lumc.nl.
• Disclosure: Nieuwenhuijse has no relevant financial disclosures.

John G. Heller

I am intrigued to learn that the outcomes for these two groups of patients following percutaneous vertebroplasty were equivalent. In my experience over the last 12 years, patients with a true clinical presentation of Kummel’s disease are uncommon and get exceptionally good results from a percutaneous cement procedure. The effect is immediate, dramatic and durable, but the diagnosis is not a purely radiographic one.

Although the imaging findings may be as described by the authors, the patient who is likely to do extremely well with such a procedure is one with months of symptoms following a osteoporotic vertebral compression fracture. But, the devil is in the details of the history and dynamic imaging studies. The patient should be essentially symptom-free when at recumbent rest (an unloaded spine). Their pain returns immediately upon sitting up or standing. One should see a mobile cleft when comparing true lateral erect and supine plain radiographs.

The authors’ patient population appears to have been defined only on radiographic grounds, not these additional clinical characteristics. Thus, the difference between their results and what I have noted over time, may be due to the inclusion criteria that they established. Consider that they note about half of such fractures fit their inclusion criteria for IVCs, whereas I might see one patient per year that meets the clinical definition offered above.

— John G. Heller, MD
The Emory Spine Center Atlanta
Disclosure: Heller is a consultant to Medtronic.