Introduction and objective: In elderly patients with reduced bone quality, insufficiency fractures of the sacrum are relatively common and are typically accompanied by severe, disabling pain. The objective of this study was to evaluate the feasibility of cement augmentation by RFS, as well as to determine postinterventional leakages and present the patients' outcomes.
Material and method: In 20 patients (18 women, 2 men) with an average age of 80.4 (65-92) years, a fracture of the sacrum was detected by CT and MRI. Clinically manifest osteoporosis with QCT values of below 50 mg/ml was found in all patients. An initially performed conservative treatment over a period of 3 weeks did not achieve a satisfactory reduction in the severe, disabling pain. The cement augmentation was performed under CT guidance by means of RFS under intubation anaesthesia. A Jamshidi needle was advanced into the respective fracture zone in the sacrum from dorsal to ventral (short axis) or from lateral to medial transiliac (transiliac axis). After removing the inner needle, a flexible osteotome was inserted through the positioned hollow needle and used to extend the spongious space in the fracture zone and thus prepare a cavity for the cement filling. The highly viscous polymethyl methacrylate (PMMA) cement, activated by radiofrequency, was then inserted into the prepared fracture zone through a substituted screw cannula. Cement filling was performed discontinuously under instrumental guidance at 1.3 ml/min under CT guidance. Cement leakages were determined in CT images and conventional X-rays on the day after the intervention. Pain was documented on a visual analogue scale (VAS) on the day before the intervention, on the second day, and after 6 and 12 months after the intervention. Additionally occurring complications were recorded, and the patients were asked to state how satisfied they were after 12 months.
Results: RFS was technically feasible in all patients. In the control CT scans and X-rays, sufficient cement distribution and interlocking with vital bone was found along the course of the fracture in the sacrum. 7.2 (4-9) ml of cement were inserted per fracture. Leakage could be ruled out. The mean pain score on the VAS was 8.8 ± 1.2 before the intervention, and a significant reduction in pain (p < 0.001) was seen on the second postoperative day, with an average value of 2.3 ± 0.7, which was stable at 2.2 ± 1.3 after 6 months and 2.1 ± 1.1 after 12 months. All of the patients could be fully re-mobilised and discharged back home. A high level of patient satisfaction was found after 12 months, with 18 of the 20 patients stating that they would undergo the intervention again. One patient died of a stroke, another of cancer over the course.
Conclusion: As a minimally invasive procedure, RFS is an effective and safe method of treatment for rapid, significant and sustained pain reduction.