The Clinical Feasibility Of Minimally Invasive Transforaminal Lumbar Interbody Fusion With Intraoperative Computed Tomography-Guided Navigation System

Objective:To compare the clinical outcomes of the minimally invasive transforaminal lumbar interbody fusion with Intraoperative Computed Tomography(iCT-MIS-TLIF) Navigation System, minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) and conventional open transforaminal lumbar interbody fusion (COTLIF) for single-level lumbar fusion surgery, by which to evaluate clinical effects and feasibility of the MIS-TLIF by assistance of iCT Navigation System.Methods:From April,2009 to September,2011,45 patients diagnosed as lumbar disc herniation (LDH) were treated by one team of surgeons at a single institution,iCT-MIS-TLIF in 11 and MIS-TLIF in 15 and COTLIF in 19, taking patient's condition into consideration and voluntarily chosen by patients. All patients were followed up 24months. The detailed procedures, preoperative, and intraoperative images were illustrated. The operation time, intraoperative blood loss, postoperative blood loss (drain), preoperative and postoperative pain scale of low back and leg pain Visual Analogue scores (VAS) (3days,1.5,3,6,12,24months postoperatively), complications, postoperative hospital stay, postoperative ambulation time and X-ray examination from each group were evaluated before surgery, after surgery and follow-up. The iCT scanning data were analyzed.Results:All of the 45 patients experienced an improvement in leg and back pain without complications and new neurologic deficits. There were no significant differences between iCT-MIS-TLIF and MIS-TLIF(except the mean operative time) in mean operative blood loss,mean postoperative blood loss,mean postoperative ambulation time andmean postoperative hospital stay, and they were lower than COTLIF group(P<0.05).Three groups of VAS and ODI score follow-up results were significantly improved compared with preoperative scores, but the iCT-MIS-TLIF and MIS-TLIF groups' low back pain VAS score after operation in 3 days, and postoperative 1.5 months ODI score were significantly lower than that of group COTLIF group. Besides, iCT-MIS-TLIF group'slow back pain VAS score after 6 weeks was significantly lower than that of COTLIF group's (P< 0.05).During the rest of follow-up time, three groups of scores showed no statistical difference. There were no significant difference in patient's age, gender, mean VAS scores of preoperative low back and leg pain, mean VAS scores of postoperative leg pain during follow-up, mean VAS scores of low back pain of postoperative 1.5th,3th,6th,12th,and 24th month and lumbar fusion rate among three groups. There were no reoperation in each groups during follow-up. In the iCT-MIS-TLIF group, the mean automatic image registration time is 45.5 seconds, the iCT scanning time is 9 seconds, the mean time-out for intraoperative scanning is 5.8 minutes, and the mean total number of CT scans per patient is 3.1 minutes.Conclusions:The minimally invasive approach caused less change in multifidus, less postoperative back pain and functional disability than conventional open approach. Preliminary experience with the first 11 patients confirms the feasibility of iCT scanning and integrated navigation system in the minimally invasive lumbar instrumentation. MITLIF with iCT Navigation System has similar good long-term clinical outcomes and high fusion rates of COTLIF with the additional benefits of less early postoperative back pain and functional disability, early rehabilitation, shorter hospitalization.Besides,for the patients with complex anatomical structure,the iCT navigation system might provide better accuracy and safety of posterior spinal instrumentation without additional soft tissue stripping.