Vertebroplasty Compared With a Sham-procedure for Painful Acute Osteoporotic Vertebral Fractures

The objective of this study is to evaluate the efficacy of bone cement injection (PVP) for patients with acute painful osteoporotic compression fractures, as compared with a simulated procedure with injection of Lidocaine. Our hypothesis is, that patients who had undergone PVP would report less pain during the first 1-12 weeks and at 12 months (primary outcomes) than those in the sham control group.

The study design of VOPE is a single center double blinded RCT concerning the treatment of patients with a painful osteoporotic VCF. Patients are referred to the principal investigator at Middelfart hospital from the emergency rooms, orthopedics departments, GP's and chiropractors from the Region of Southern Denmark. Prior to enrolling patients randomization-envelopes are constructed in blocks of 20. Upon obtaining informed consent, a study-number is assigned to each patient. The final randomization for each patient, takes place in the operation room upon opening the sealed envelope deciding which of the two operations are to be performed. A total of 80 patients will be enrolled, 40 in each group. This is based on the assumption of a 2.0 point difference in pain relief (VAS Score) and a maximum of 35% withdrawal rate (α=0.05 and β=0.20). The enrolment of patients will take place in a single center, the spine surgery department of Middelfart hospital in Denmark. Randomization will start February 2012 with an expected completion of enrolment by May 2013. There is a one-year follow-up, with the possibility of an extended follow-up at two years.

The overall Institutional Review Board approval is obtained at Middelfart Hospital.

Osteoporosis- and pain medication:

All patients are, in cooperation with the osteoporosis clinic at Odense University Hospital (OUH), DXA-scanned 3 times during the follow-up period, and receives, regarding these results, the correct antiosteoporotic treatment determined by a endocrinology senior consultant. Analgesics are classified following the WHO classification: (1) Paracetamol (acetaminophen), (2) Tramadol, (3) Tramadol and Paracetamol, (4) Morphine.

Clinical follow-up:

An experienced nurse-practitioner and research consultant requests patients to fill out a standard questionnaire before and at 1 day, 1-11 weeks, and 3 and 12 months after the procedure. The patients will receive a folder including questionnaires for each of the first 11 weeks and will be contacted by telephone once every week and asked to fill out the questionnaires. The questionnaire consist of the VAS and NRS score and questions about use of pain medication. The VAS score is a 10 cm line pain score ranging from "no pain" to "worst pain ever", the NRS is a similar tool where patients are asked in 3 different ways to describe their pain between 0 and 10 where 10 is the worst pain ever. Other medical treatment is registered at 0, 3 and 12 months.

Secondary outcomes are back pain related disability and QOL as measured with the SF-36 Questionnaire and the EuroQol 5D Questionnaire. The EQ5D score ranges from 0 (worst quality of life) to 1 (best quality of life). This questionnaire will be completed at three measurement moments (before and at 3, and 12 months after the procedure). SF-36 scores from 0-100, (100 as the best outcome), 4 domains describing tghe physical function and 4 describing mental health. The lung capacity will be measured by the principal investigator with a spirometer at before and at 3 and 12 months.

Statistical analysis:

The data will be analysed according to the intention-to-treat principle. Standard statistical techniques will be used to describe characteristics of patients in both groups using the STATA programme. If incomparability appears at baseline, we will in secondary analysis adjust for differences. The primary outcome, significant pain relief will be compared with the analysis of variance for repeated measures. If adjustment for possible baseline incomparability is needed, analysis of covariance will be done.

Inclusion criteria

• VCF on X-ray of the spine (minimal 15% loss of height) level of VCF Th6 or lower
• back pain ≤ 8 weeks at time of surgery
• ≥ 50 years of age
• bone edema on MRI of the fractured vertebral body
• focal tenderness on VCF level

Exclusion criteria

• severe cardio-pulmonary condition
• untreatable coagulopathy
• systemic or local infection of the spine (osteomyelitis, spondylodiscitis)
• suspected alternative underlying disease (malignancy)
• radicular and/or cauda compression syndrome
• contra-indication for MRI