Real-time ultrasonography–magnetic resonance image fusion navigation for percutaneous transforaminal endoscopic discectomy

OBJECTIVE: Percutaneous transforaminal endoscopic discectomy (PTED) is usually performed under fluoroscopic guidance and is associated with a large radiation dose. Ultrasonography (US)-MR image fusion navigation combines the advantages of US and MRI and requires significantly less radiation than fluoroscopy. The purpose of this study was to evaluate the safety and effectiveness of US-MR image fusion navigation for PTED. METHODS: From January to September 2018, patients with L4-5 lumbar disc herniation requiring PTED were randomized to have the procedure conducted with US-MR image fusion navigation or fluoroscopy. The number of fluoroscopies, radiation dose, duration of imaging guidance, intraoperative visual analog scale (VAS) pain score, intraoperative complications, and clinical outcomes were compared between the groups. RESULTS: There were 10 patients in the US-MR navigation group and 10 in the fluoroscopy group, and there were no significant differences in age, sex ratio, or BMI between the 2 groups (all p > 0.05). Intraoperatively, the total radiation dose, number of fluoroscopies performed, duration of image guidance, and VAS low-back and leg pain scores were all significantly lower in the US-MRI navigation group than in the fluoroscopy group (all p < 0.05). There were no intraoperative complications in either group. Postoperative improvements in Japanese Orthopaedic Association, Oswestry Disability Index, and VAS pain scale scores were similar between the 2 groups. CONCLUSIONS: US-MR image fusion navigation is a promising technology for performing PTED and requires significantly less radiation than fluoroscopy.Clinical trial registration no.: NCT03403244 (ClinicalTrials.gov).