RESUMO
Objective:To introduce a new TIANJI robot assisted targeted puncture technique, and discuss the feasibility and clinical effect of transforaminal percutaneous endoscopic lumbar discectomy (tPELD) using this technique.Methods:The first 14 consecutive cases of single level lumbar disc herniation who underwent robot assisted tPELD procedure were retrospectively analyzed. The mean age was 46.3±16.0 years old (ranged from 16-72). After data transferred from C-arm to robot system and automatic registration, surgeons made plans of the trajectory on robot system based on intraoperative 3-dimensional images of lumbar spine. Move robotic arm to planned position, guide an accurate puncture pathway and establish working cannula. 25 consecutive patients who underwent conventional C-arm assisted tPELD surgery during the same period of time were assessed as the controlled group. The mean age was 45.5±13.7 years old (ranged from 16-68). All patients were followed up for 12 months. Clinical effect was assessed by visual analogue scale (VAS), Oswestry disability index (ODI) and Modified Macnab criteria. Intraoperative parameters and surgery-related complications were recorded.Results:The baseline data of age, surgical level, types of herniation, preoperative VAS scores and ODI had no significant difference between two groups ( P>0.05). In robot group, one case was converted to open microdiscectomy during operation due to technical failure. The other thirteen cases had successful robot assisted tPELD surgeries and were assessed accordingly. The new technique had good clinical outcomes. The immediate post-operative VAS score 2.85±1.79 and the last follow-up VAS score 1.50±1.04 were both significantly decreased than that before surgery 7.62±0.92 ( F=69.747, P<0.01); the last follow-up ODI 18.89%±12.16% was significantly reduced from the pre-operative ODI 71.19%±12.12% ( t=15.430, P<0.01). Between two groups, the immediate post-operative VAS score ( t=0.568, P=0.574), the last follow-up VAS score ( t=0.713, P=0.481), and last follow-up ODI had no significant difference ( t=0.171, P=0.865). The excellent or good rate of modified Macnab criteria at the last follow-up was 92.30% in robot group, comparing to 84.0% in controlled group. The fluoroscopic times during surgery of robot group 8.8±5.5 was significantly lowered the in controlled group 21.3±8.3 ( P<0.01). One case in robot group and two cases in controlled group had recurrence during follow-up period (recurrence rate 7.7% vs. 8.3%). However, there was no significant complications such as nerve root injury, dura injury or increased intracranial pressure in both groups. Conclusion:This study confirmed the feasibility of this new technique. Preliminary results indicated that TIANJI robot could help to build an easy, accurate and safe procedure of tPELD surgery.