Comparison of the 18-month outcome after the treatment of osteoporotic insufficiency fractures by means of balloon sacroplasty (BSP) and radiofrequency sacroplasty (RFS) in comparison: a prospective randomised study

Purpose: The objective of this prospective, randomised study was to examine the feasibility and clinical outcome of balloon sacroplasty and radiofrequency sacroplasty.

Methods: In 40 patients with a total of 57 sacral fractures, CT-guided cement augmentation was performed by means of BSP or RFS. For BSP, the balloon catheter was inflated and deflated in the fracture zone, and the hollow space, thus, created was then filled with PMMA cement. For RFS, the spongious space in the fracture zone was initially extended using a flexible osteotome, and the highly viscous PMMA cement, activated by radiofrequency, was then inserted into the prepared fracture zone. Pain intensity was determined on a VAS before the intervention, on the second day, and 6, 12 and 18 months after the intervention. The results were tested for significance by means of paired Wilcoxon rank-sum tests and Mann-Whitney U tests.

Results: BSP and RFS were technically fully feasible in all patients. An average of 6.3 ml cement per fracture was inserted in the BSP group and an average of 6.1 ml per fracture in the RFS group. Leakage could be ruled out for both procedures. The mean pain score on the VAS before the intervention was 8.6 ± 0.55 in the BSP group and 8.8 ± 0.58 in the RFS group. On the second postoperative day, a significant pain reduction was seen (p < 0.001), with an average value of 2.5 (BSP ± 0.28, RFS ± 0.38) for both groups. After 6 (12; 18) months, these values were stable for the BSP group at 2.3 ± 0.27 (2.3 ± 0.24; 2.0 ± 0.34) and for the RFS group at 2.4 ± 0.34 (2.2 ± 0.26; 2.0 ± 0.31). With regard to pain, exceedance probability values of p = 0.86 (6 months), p = 0.94 (12 months) and p = 1 (18 months) were seen, so that neither treatment method leads to differences in results.

Conclusions: BSP and RFS are interventional, minimally invasive procedures that enable reliable cement augmentation and achieve equally good clinical outcomes in the medium term.