The conservative therapy of sacral insufficiency fractures with immobilisation and pharmacotherapy of pain and osteoporosis [
18] leads to an increase in other comorbidities as a result of the immobilisation and often only brings clinical improvement in the long term [
5,
19]. Since a rapid analgesic effect with a positive effect on mobility and the activities of daily living has been repeatedly shown after sacroplasty [
4,
8,
9,
11,
13,
14], this therapeutic option should be taken after an unsuccessful attempt at conservative treatment with persistent disabling pain. Cement augmentation analogous to vertebroplasty [
8‐
10] or balloon kyphoplasty [
4,
9,
11,
13,
14] come into question here. Greater clinical experience has been gained in cement insertion via a placed hollow needle in accordance with vertebroplasty, although higher rates of cement leakage are experienced here, as in the treatment of vertebral body fractures [
9,
10]. A central cavity for insertion of the cement can be created using a balloon catheter, whereby a compaction of the surrounding fracture zone seals possible fracture fissures and thus minimises cement leakage [
4,
12‐
14]. On the basis of good clinical experience [
20,
21] with regard to pain reduction, a low rate of leakage and vertebral body reconstruction with highly viscous cement insertion by means of radiofrequency kyphoplasty on the spine and initial good results after RFS with regard to pain reduction [
15‐
17], we also treated 20 patients with osteoporotic insufficiency fractures of the sacrum by means of radiofrequency-guided cement insertion. As reported by Klingler et al. [
16] and Eichler et al. [
17], we also observed a significant pain reduction in all patients. Klingler et al. [
16] found asymptomatic PMMA leakages in 100 % of their cases and Eichler et al. in 5.5 %, in contrast to 0 % in our study. The approaches selected were possibly disadvantageous, taking into account the complex anatomy of the sacrum, as the approach chosen in the two studies was via the long axis [
22], whereas we chose an approach via the short or transiliac axis [
23,
24]. A further advantage of the short and transiliac axis is the imaging of the entire needle of the application system in the axial CT image. Here, individual CT images can be examined during cement application to predict and prevent a leakage, whereby the possibility of interrupting hydraulic insertion of the highly viscous cement by remote control is a great advantage [
25]. In our opinion, the procedure should be done under CT guidance due to the fact that under fluoroscopy the reduced bone structure, as usually found in osteoporotic patients, as well as the complex three-dimensional anatomy of the sacrum can not be reliably visualised. As a minimally invasive procedure, RFS is an effective, safe method of treatment for rapid, significant and sustained pain reduction. In the case of CT-guided RFS, the approaches via the short or transiliac axis appear to be the safest. Based on the available evidence RFS is an option to treat sacral fractures after failed conservative treatment.