Thursday, 11 April 2019 10:10

ISASS Reaffirms support for vertebral augmentation for VCFs

Vertebroplasty and kyphoplasty remain the treatments of choice for patients with painful vertebral compression fractures according to an updated review of literature by an expert panel of the International Society for the Advancement of Spine Surgery (ISASS).

The panel reviewed the body of literature and found an overwhelming body of evidence supporting vertebral augmentation which they published in the International Journal of Spine Surgery.

Vertebral compression fractures are common, particularly among older adults with osteoporosis. Since introduction of acrylic-based cement for vertebral augmentation in 1987 more than 52 level 1 and 2 studies have demonstrated the superiority of vertebroplasty over conservative therapy for treatment of pain from compression fractures.

Prior to 2009 the reviewers found that in all but three studies (Buchbinder, Kallmes and VERTOS I) vertebroplasty and balloon kyphoplasty were shown to be superior to non-surgical management for pain reduction, mobility, disability, quality of life, increased vertebral body height, reduced hospitalization, and lower mortality.

The three studies with negative results compared vertebroplasty to “sham” treatments. After analysis of the study designs, the panel and others found that the sham treatments were in fact active treatments and the amount of cement injections in the vertebroplasty groups were insufficient in some cases, which diminished the difference in outcomes between the two groups in all three studies.

In 2009, a pair of multi-center, double-blind prospective randomized controlled trials (Buchbinder and Kallmes) published in the New England Journal of Medicine compared patients treated with vertebroplasty with patients treated with a sham procedure. The sham procedure in the first study involved inserting a 13-guage needle within the periosteum, the second study’s comparison treatment involved injections of anesthetic on the periosteum.

The first trial compared 30 patients treated with vertebroplasty and 40 treated with the sham procedure. The second trial compared 68 vertebroplasties to 63 anesthetic injections. Results of both trials showed no significant difference between the groups in terms of pain, quality of life, and disability.

Critics of the two studies pointed out that the amount of cement injected in the vertebroplasty groups were either not reported or was insufficient. Other design flaws included patient selection, lack of physical examination that included patients with low pain scores prior to treatment. All of which would tend to diminish the differential in outcomes.

In addition to these now downgraded studies, a Canadian study found vertebral augmentation more cost effectiveness than conservative management, and a German analysis of claims data, showed balloon kyphoplasty is more cost effective than vertebroplasty for pain control and reducing costs for oral narcotics.

Despite all the evidence contrary to the NEJM studies, reimbursement for vertebral augmentation dropped and recommendations by UpToDate and other provider publications became unfavorable toward vertebral augmentation. As a result, US Medicare patients treated with vertebroplasty declined from a high of 24% in 2007-2008 to 14% in 2014.

Since then the VERTOS II, and VAPOUR trials designed to address the shortcomings of the NEJM studies were published. The 2010 VERTOS II trial showed long-lasting pain relief from vertebroplasty compared to conservative management.

The 2016 VAPOUR trial showed vertebroplasty reduced numeric rating score for pain from an average of 7 out of 10 before treatment to below 4 in 44% of patients compared to only 21% of the control group treated with subcutaneous lidocaine injections at two weeks follow-up and up to six months.

The EVOLVE trial was the largest vertebral augmentation study to date with 354 patients treated with balloon kyphoplasty. The patients were evaluated at multiple intervals over a period of 12 months on the Numerical Rating Scale (NRS) for back pain, Oswestry Disability Index (ODI), Short Form-36 Questionnaire Physical Component Summary, and the EuroQol-5-Domain. At every interval, the scores for each measure demonstrated significantly greater benefit for patients treated with balloon kyphoplasty compared to their baseline scores.

The ISASS panel also reviewed three meta-analyses that examined data from a total of 58 studies. The first two showed superior pain relief and lower rates of subsequent fractures compared to nonsurgical management.

The third meta-analysis included six studies with quantitative analysis comparing vertebroplasty with nonoperative or sham treatments. It found cement augmentation resulted in greater pain relief, functional recovery, and health-related quality of life than nonoperative or sham treatment.

Similar to the 2009 studies, the ISASS panel found the 2018 VERTOS IV study also had deficiencies with regard to volume of cement injected in the vertebroplasty group, physician evaluation of patients, and lack of consideration of refracture and adjacent fractures in the outcomes. Consequently, the impact of this most recent study seems to have been significantly diminished.

Based on this review of the evidence, the ISASS panel concluded that the current body of literature, including 52 level 1 and 2 studies and 3 meta-analyses, strongly favors vertebral augmentation procedures compared to non-surgical management and has updated its Policy Statement on vertebral augmentation reaffirming its strong support for vertebral augmentation particularly kyphoplasty for the treatment of vertebral compression fractures.