Comparison of radiofrequency kyphoplasty (RFK) and balloon kyphoplasty (BKP) in the treatment of vertebral compression fractures

BACKGROUND Balloon kyphoplasty (BKP) is a widely adopted minimally invasive treatment for vertebral compression fractures (VCFs), but leakage of cement is a main complication of BKP. A novel vertebral augmentation technique radiofrequency kyphoplasty (RFK) with high viscosity cement was developed in 2009. Here, we aim to evaluate whether RFK can relieve symptoms efficiently and reduce cement leakage. METHODS A literature search was performed using Pubmed, Embase, and Cochrane CENTRAL until September 30, 2016. Both randomized controlled trial (RCT) and non-RCT studies comparing RFK and BKP were included. The main outcomes included pain relief (VAS), functionality improvement (ODI), operation time, reduction of deformity (vertebral height and kyphosis angle), and incidence of cement leakage. The origin of heterogeneity was further explored by subgroup stratification. RESULTS A total of 6 studies involving 833 patients with VCFs were included. The reduction of VAS score in the RFK group was 3.96 points more than that in the BKP group (P  =  .0007) postoperatively, and the improvement persisted until 12 months after the surgery (P < .00001). The operation time was shorter in RFK group than that in BKP group (P  =  .01). The increase of anterior vertebral height shortly after the operation was 0.53 mm greater in RFK group (P  =  .01). The decrease of kyphotic angle after RFK was 0.63° and 0.92° greater than that after BKP, both immediately and 6 months after operation (P  =  .002 and P < .00001, respectively). There was no significant difference between the incidence of cement leakage after RFK and BKP (P  =  .06). Further subgroup analysis stratified by study design indicated that the incidence of leakage decreased 15% in RFK than BPK (P < .00001) in non-RCT subgroup, but RFK and BKP treatments were equivalent in the RCT studies (P  =  .86). CONCLUSION RFK appears to be more effective and safer than BKP in the present meta-analysis. The incidence of cement leakage diverges in RCT and non-RCT studies, so large-sample multicentered RCT studies are required to validate this new surgery system.