Objectives:To investigate the pedicle screw placement accuracy of robot-assisted minimally inva-sive transforaminal lumbar interbody fusion(RA-MIS-TLIF)and analyze its learning curve.Methods:A retro-spective analysis was conducted on the clinical data of 160 patients with degenerative lumbar diseases treated at the Department of Orthopedics,Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hos-pital between January 2019 and June 2022.The patients were divided into a robot group(n=80)and a manual group(n=80)based on the surgical approach.Each group was further divided into four subgroups(1,2,3,4)of 20 patients each,arranged sequentially according to the order of surgery dates.The total operative time,blood loss,and planning and screw placement time of the two surgical methods were statistically analyzed.Preoper-ative,postoperative 1d,and six-month postoperative visual analogue scale(VAS)scores for pain and Oswestry disability index(ODI)were compared across the four subgroups.The trends in total operative time and blood loss with increasing surgery cases were analyzed using a logarithmic regression model.Screw placement clas-sification was evaluated using the Gertzbein-Robbins classification based on postoperative CT scans,and then the screw placement accuracy was calculated.Results:All the surgeries were successfully completed.In the robot group,the total operative time was 162.9±5.7min,blood loss was 91.4±9.5mL,and planning and screw placement time was 42.1±1.3min;In the manual group,the total operative time was 169.1±6.6min,blood loss was 101.0±9.2mL,and planning and screw placement time was 57.0±6.3min.A total of 320 screws were placed in each group,with accuracy rates of 97％(311/320)in the robot group and 92％(295/320)in the manual group.Neither group had grade C or D screws.The total operative time decreased with the increase in the number of surgeries in both groups.The robot group achieved relative stability between subgroups 2 and 3[y=-5.894×ln(x)+183.891,R2=0.576,P＜0.05],while the manual group achieved relative stability between subgroups 3 and 4[y=-4.424×ln(x)+184.221,R2=0.376,P＜0.05].The blood loss also decreased with the increase in the number of surgeries in both groups,the robot group achieved relative stability between subgroups 2 and 3[y=-9.480×ln(x)+125.361,R2=0.547,P＜0.05],and the manual group achieved relative stability also between subgroups 2 and 3[y=-3.868×ln(x)+114.183,R2=0.148,P＜0.05].Postoperative VAS scores in the robot group decreased from 6.9±1.1 preoperatively to 2.4±0.9 on postoperative 1d(P＜0.05)and to 1.1±0.4 at six months(P＜0.05).In the manual group,VAS scores decreased from 7.0±0.9 preoperatively to 2.4±0.9 on postoperative 1d(P＜0.05)and to 1.4±0.6 at six months(P＜0.05).ODI in the robot group decreased from(59.5±7.1)％preoperatively to(20.0±4.1)％on postoperative 1d(P＜0.05)and to(10.8±3.0)％at six months(P＜0.05).In the manual group,ODI scores decreased from(57.7±6.9)％preoperatively to(19.6±4.6)％on postoperative 1d(P＜0.05)and to(11.3±3.4)％at six months(P＜0.05).All the 160 patients completed follow-ups with no severe complications reported during the follow-up period.Conclusions:Comparing with traditional MIS-TLIF with manual pedicle screw placement,RA-MIS-TLIF has a higher accuracy of screw placement and a smoother learning curve,which stabilizes after approximately 20 cases.

Objectives:To investigate the pedicle screw placement accuracy of robot-assisted minimally inva-sive transforaminal lumbar interbody fusion(RA-MIS-TLIF)and analyze its learning curve.Methods:A retro-spective analysis was conducted on the clinical data of 160 patients with degenerative lumbar diseases treated at the Department of Orthopedics,Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hos-pital between January 2019 and June 2022.The patients were divided into a robot group(n=80)and a manual group(n=80)based on the surgical approach.Each group was further divided into four subgroups(1,2,3,4)of 20 patients each,arranged sequentially according to the order of surgery dates.The total operative time,blood loss,and planning and screw placement time of the two surgical methods were statistically analyzed.Preoper-ative,postoperative 1d,and six-month postoperative visual analogue scale(VAS)scores for pain and Oswestry disability index(ODI)were compared across the four subgroups.The trends in total operative time and blood loss with increasing surgery cases were analyzed using a logarithmic regression model.Screw placement clas-sification was evaluated using the Gertzbein-Robbins classification based on postoperative CT scans,and then the screw placement accuracy was calculated.Results:All the surgeries were successfully completed.In the robot group,the total operative time was 162.9±5.7min,blood loss was 91.4±9.5mL,and planning and screw placement time was 42.1±1.3min;In the manual group,the total operative time was 169.1±6.6min,blood loss was 101.0±9.2mL,and planning and screw placement time was 57.0±6.3min.A total of 320 screws were placed in each group,with accuracy rates of 97％(311/320)in the robot group and 92％(295/320)in the manual group.Neither group had grade C or D screws.The total operative time decreased with the increase in the number of surgeries in both groups.The robot group achieved relative stability between subgroups 2 and 3[y=-5.894×ln(x)+183.891,R2=0.576,P＜0.05],while the manual group achieved relative stability between subgroups 3 and 4[y=-4.424×ln(x)+184.221,R2=0.376,P＜0.05].The blood loss also decreased with the increase in the number of surgeries in both groups,the robot group achieved relative stability between subgroups 2 and 3[y=-9.480×ln(x)+125.361,R2=0.547,P＜0.05],and the manual group achieved relative stability also between subgroups 2 and 3[y=-3.868×ln(x)+114.183,R2=0.148,P＜0.05].Postoperative VAS scores in the robot group decreased from 6.9±1.1 preoperatively to 2.4±0.9 on postoperative 1d(P＜0.05)and to 1.1±0.4 at six months(P＜0.05).In the manual group,VAS scores decreased from 7.0±0.9 preoperatively to 2.4±0.9 on postoperative 1d(P＜0.05)and to 1.4±0.6 at six months(P＜0.05).ODI in the robot group decreased from(59.5±7.1)％preoperatively to(20.0±4.1)％on postoperative 1d(P＜0.05)and to(10.8±3.0)％at six months(P＜0.05).In the manual group,ODI scores decreased from(57.7±6.9)％preoperatively to(19.6±4.6)％on postoperative 1d(P＜0.05)and to(11.3±3.4)％at six months(P＜0.05).All the 160 patients completed follow-ups with no severe complications reported during the follow-up period.Conclusions:Comparing with traditional MIS-TLIF with manual pedicle screw placement,RA-MIS-TLIF has a higher accuracy of screw placement and a smoother learning curve,which stabilizes after approximately 20 cases.

BACKGROUND:Minimally invasive surgery is developing rapidly.Robot-assisted minimally invasive transforaminal lumbar interbody fusion and robot-assisted unilateral biportal endoscopic transforaminal/posterior lumbar interbody fusion are important posterior minimally invasive surgical approaches to treat lumbar degenerative diseases.However,it is worth discussing which operation method is more advantageous. OBJECTIVE:To compare the clinical efficacy and imaging examination between different operation groups,and discuss the clinical application value of robot-assisted minimally invasive lumbar posterior fusion technology to treat lumbar degenerative diseases. METHODS:Clinical data of 83 patients with lumbar degenerative diseases from January 2018 to June 2022 at the Department of Orthopedics,Sichuan Academy of Medical Sciences&Sichuan Provincial People's Hospital were retrospectively analyzed.Of them,27 patients received robot-assisted minimally invasive transforaminal lumbar interbody fusion treatment(group A);30 patients received robot-assisted unilateral biportal endoscopic transforaminal/posterior lumbar interbody fusion treatment(group B),and 26 traditional minimally invasive transforaminal lumbar interbody fusion patients were selected as the control group(group C).There were no significant differences in gender,age,body mass index,surgical segment,preoperative visual analog scale score and Oswestry Disability Index among the three groups(P＞0.05).The operation time,intraoperative blood loss,complications,fluoroscopic dose,fluoroscopic time,and fluoroscopic frequency were compared among the three groups.Gertzbein-Robbins'classification was used to evaluate the accuracy of percutaneous pedicle screw.Visual analog scale and Oswestry Disability Index scores were evaluated after surgery.The excellent and good rate of the three surgical options was evaluated using Macnab's criteria. RESULTS AND CONCLUSION:(1)The operation time of group A was significantly shorter than that of groups B and C(P＜0.05),but there was no significant difference between group B and group C(P＞0.05).The intraoperative blood loss in group B was significantly less than that in group A,and that in group A was significantly less than that in group C(P＜0.05).(2)The fluoroscopic dose,fluoroscopic time,and fluoroscopic frequency of group C were significantly higher than those of groups A and B(P＜0.05).(3)Visual analog scale score and Oswestry Disability Index in the three groups significantly improved after operation when compared with that before operation(P＜0.05),but there was no significant difference among the three groups 1 day and 6 months after surgery(P＞0.05).(4)Postoperative imaging showed that the accuracy of percutaneous pedicle screw placement in groups A and B was better than that in group C(P＜0.05).(5)There was no significant difference in the excellent and good rate of MacNab criteria among the three groups(P＞0.05).(6)There was no significant difference in complications among the three groups(P＞0.05).(7)The results indicated that robot-assisted minimally invasive transforaminal lumbar interbody fusion and robot-assisted unilateral biportal endoscopic transforaminal/posterior lumbar interbody fusion are effective surgery methods for lumbar degenerative diseases.Compared with traditional minimally invasive transforaminal lumbar interbody fusion,robot-assisted minimally invasive transforaminal lumbar interbody fusion surgery has higher efficiency,less intraoperative radiation and higher internal fixation accuracy,which has a good clinical application value.