Devoted to diagnostic and interventional spine imaging and therapeutics


Impact of sham controlled vertebroplasty trials on referral patterns at two academic medical centers 2011

Interventional Spine

Sara, S, Lindsey, M.D.
David, F, Kallmes, M.D., Non ASSR Member
Elizabeth, Broyles, R.N., Non ASSR Member
Michael, J, Opatowsky, M.D., Non ASSR Member
Kennith, F, Layton, M.D., Non ASSR Member



Substantial debate persists within the medical community regarding the merit of vertebroplasty following publication of the Investigational Vertebroplasty Safety and Efficacy Trial (INVEST) in the New England Journal of Medicine 08/2009, which demonstrated equivalent efficacy between vertebroplasty and a sham intervention for improvement in pain and function in patients suffering from osteoporotic compression fractures. The purpose of this current study was to determine whether referring physicians at two academic medical centers, one of which (Mayo Clinic) was the lead site for INVEST, were aware of the INVEST trial results, whether their awareness of these results changed both their understanding of the efficacy of vertebroplasty and their management decisions for patients suffering from painful osteoporotic fractures, and whether there were differences between institutions regarding these research questions.

Methods & Materials

Short email surveys were distributed to physicians in a wide range of specialties that commonly encounter patients with osteoporotic compression fractures within the Mayo Clinic system (Rochester, MN) and the Baylor Health Care System (Dallas-Ft.Worth Metroplex, TX). Results were collected and analyzed using Survey MonkeyTM. Approval for this research was granted by the Baylor University Medical Center IRB. The survey asked participants about their familiarity with the INVEST study, their understanding of the role of vertebroplasty for treatment of osteoporotic compression fractures, if the INVEST results changed their understanding of the treatment for osteoporotic compression fractures or changed their referral patterns for vertebroplasty, and how they were currently treating patients with painful osteoporotic compression fractures. Statistical analysis of the data was performed with Chi Square tests.


Surveys were distributed to 1390 clinicians with a collective response rate of 14% (194 participants). Overall, 92 (58%) of 158 respondents reported being familiar with INVEST. 53 (58%) of these 92 respondents agreed and 13 (14%) strongly agreed that the results of INVEST had changed their understanding of the efficacy of vertebroplasty; 51 (55%) agreed and 13 (14%) strongly agreed that the study had diminished their enthusiasm to refer patients for vertebroplasty. Cumulatively, 105 (66%) respondents felt that vertebroplasty was an effective procedure in appropriate patients, 52 (33%) respondents felt that vertebroplasty was of limited efficacy and 2 (1.3%) respondents felt that the potential benefits of vertebroplasty were outweighed by the risks of the procedure. There was a statistically significant difference in the responses between clinicians in the two geographic locations, with Mayo physicians being more aware of the INVEST study (Chi-Square DF 1, Prob <0.001) and responding that INVEST had changed their understanding of the appropriate treatment for osteoporotic compression fractures (Chi-Square DF 1, Prob 0.026). There was also a statistically significant difference between clinicians in the two locales in response to descriptions of their current understanding of vertebroplasty for treatment of osteoporotic compression fractures (Chi-Square DF 2, Prob 0.005) with Mayo clinicians viewing vertebroplasty less favorably. A majority of respondents from both clinician groups indicated that the INVEST results had diminished their willingness to refer patients for vertebroplasty (63% Baylor respondents, 73% of Mayo respondents) although no statistical significance existed between the two respondent groups for this question (Chi-Square DF 1, Prob 0.366). Mayo clinicians were also statistically significantly more likely than Baylor clinicians to treat osteoporotic compression fracture patients with medical therapy and pain management alone, rather than in combination with vertebroplasty (Chi-Square DF 1, Prob 0.003).


INVEST changed cliniciansâ