Kyphoplasty with an intravertebral reduction device for osteoporotic vertebral compression fractures with spinal canal encroachment

Background: To compare the radiological and clinical outcomes of kyphoplasty (KP) with intravertebral reduction device (IRD) and vertebroplasty (VP) for treating osteoporotic vertebral compression fracture (OVCF)-associated spinal canal encroachment (SCE). Materials and Methods: From January 2013 to December 2016, 57 patients with OVCF-associated SCE treated through VP or KP with an IRD were enrolled. Kyphotic angle (KA) anterior, middle, and posterior body heights (ABH, MBH, and PBH, respectively) at postoperative week 1 3, 6, and 12 months of the cemented vertebrae were evaluated. Visual analog scale (VAS), Oswestry Disability Index (ODI), and EuroQol-5D-5 L (EQ-5D-5 L) were followed, and the complications were recorded. Results: Sixteen and 41 patients were treated through KP with IRD and VP (IRD and VP groups, respectively), and their characteristics were comparable. Compared with the VP group, KA, ABH, MBH, and PBH in the IRD group were significantly greater after the operation at postoperative 12 months (IRD vs. VP: KA -1.68° ± 6.02° vs. -10.34° ± 4.99°; ABH 2.06 ± 0.29 vs. 1.35 ± 0.26; MBH 2.21 ± 0.51 vs. 1.21 ± 0.31; PBH 2.91 ± 0.62 vs. 2.11 ± 0.33 cm, P< 0.05). Significant postoperative improvements were observed in the VAS, ODI, and EQ-5D-5 L in both groups; these improvements were similar between the two groups. No new neurological deficits occurred, and the incidence rates of cement leakage into the SC were similar. Conclusions: KP with IRD was associated with better body heights and KA at least for 1 year for OVCF-associated SCE with noninferior clinical outcomes to VP.