Risk factors for the development of chronic back pain after percutaneous vertebroplasty versus conservative treatment

In a recent randomized controlled trial comparing vertebroplasty (VP) versus conservative treatment (CT) in patients with symptomatic vertebral fractures (VF), we observed the development of chronic back pain (CBP) in nearly one-quarter of patients. The aim of this study was to identify the risk factors related to the development of severe CBP in these subjects. We evaluated risk factors including visual analog scale (VAS) at baseline and during the 1-year follow-up, age, gender, symptom onset time, number, type and severity of VF at baseline, number of vertebral bodies treated, incident VF, and antiosteoporotic treatment, among others. CBP was considered in patients with VAS ≥ 7 at 12 months. 91/125 patients completed the 12-months follow-up. CBP was observed in 23% of VP-treated patients versus 23% receiving CT. Patients developing CBP after VP showed a longer symptom onset time (82% ≥ 4 months in VP vs. 40% in CT, P = 0.03). On univariate analysis, female gender (OR 1.52; 95% CI 1.47-1.57, P < 0.0001), multiple acute VF (OR 1.79; 95% CI 1.71-1.87, P < 0.0001), VAS ≥ 7 two months after treatment (OR 11.04; 95% CI 6.71-18.17, P < 0.0001), and type of antiosteoporotic drug (teriparatide) (OR 0.12; 95% CI 0.03-0.60, P = 0.0236) were risk factors of CBP development in both groups. In the multivariate analysis, the main risk factors were baseline and post-treatment VAS ≥ 7, longer symptom onset time, and type of antiosteoporotic treatment. In conclusion, 23% of patients with symptomatic osteoporotic VF developed severe CBP independently of the type of treatment. Symptom onset time before VP and persistence of severe CBP after treatment were the main factors related to CBP with teriparatide treatment decreasing the risk of this complication.