Percutaneous Vertebroplasty Versus Conservative Treatment in Vertebral Compression Fracture Associated With Glucocorticoids-induced Osteoporosis: a Prospective Cohort Study

Patient recruitment and informed consent The study will recruit patients with GIOPVCF after consultation with inpatients and outpatients. The principal investigator of the study will screen the clinical information and inform the patients whether they are eligible for the study. After explaining the two therapeutic strategies (conservative treatment and PVP) and signing the informed consent, the patients will be divided into conservative treatment or PVP group based on their own decision.

The general information and medicine history of the participants are collected: age, gender, original disease, the course of original disease, specific GCs that have been used, the dosage/length of the GCs treatment, specific anti-osteoporosis medicine have been used and the dosage and length of usage. The bone density of the patient will then be evaluated using Dual-energy X-ray absorptiometry (DXA).

Withdrawal of individual subject Patients can withdraw from the study at any time for any reason without any consequences. The investigator can also decide to release patients from the study for medical reasons. For every patient who decides to withdraw from the study, the reasons of withdrawal will be recorded.

Sample size calculation A p-value is less than significance level (α) of 0.05 is considered as statistically significant. The statistical power (1-β) is defined as 80%. Based on the survival analysis of primary endpoint , the incidence of refracture in the patients with GIOPVCF is 48.6% after initial PVP operation and 17% after initial conservative treatment. Thus, power analysis indicates the study requires 42 patients per group to achieve statistical significance between two groups. Considering 20% of patients may be lost during follow-up visits, the investigators will recruit 53 patients for each group.

Statistical analysis Standard statistical techniques will be used to describe characteristics of patients in both groups. The investigators will compare baseline characteristics in the two treatment groups and if incomparability appears, the investigators will in secondary analysis adjust for differences. The incidence of vertebral refracture between groups will be compared with the Kaplan Meier survival analysis. Baseline differences of pain relief and health-related life quality between two groups will be assessed using student t test or nonparametric tests. Changes of VAS, ODI, and EQ-5D within the group from baseline to every follow-up time point will be compared using paired t test. A P value less than 0.05 is considered as statistically significant. SPSS 17.0 statistical program (SPSS, Chicago, IL) will be used for statistical analysis.