机器人辅助皮质骨轨迹螺钉内固定术治疗腰椎退行性疾病的置钉准确率及学习曲线分析

Analysis of screw placement accuracy and learning curve of robot-assisted cortical bone trajectory internal fixation in the treatment of lumbar degenerative diseases

目的:评估骨科机器人辅助皮质骨轨迹(cortical bone trajectory,CBT)螺钉内固定技术在腰椎退行性疾病中应用的置钉准确率、皮质接触情况以及该技术的学习曲线。方法:回顾性分析2019年10月~2021年4月应用“天玑”骨科手术机器人辅助置入CBT螺钉治疗45例L4-5退行性疾病患者的资料,其中男性27例,女性18例,年龄64.3±6.9岁,腰椎间盘突出症8例,腰椎管狭窄症28例,退变性腰椎滑脱症9例。按患者接受手术日期先后顺序平均分为A、B、C三组,每组15例。统计手术时间、出血量,术前及术后6个月时进行VAS和JOA评分,采用ln曲线回归分析方法分析手术时间随手术例数变化的趋势,术后通过CT评估置钉准确率及皮质接触层数,随访期间通过X线片及CT观察螺钉松动、椎间融合、融合器沉降及移位情况。结果:患者均顺利完成手术,手术时间140~195min(163.5±11.3min),出血量140~265ml(210.0±28.9ml)。共置入166枚螺钉,螺钉可接受率为97%(161/166),平均总皮质骨接触层数为4.9±0.6层,平均椎弓根皮质骨接触层数为3.3±0.6层。B、C组手术时间及出血量较A组减少,差异有统计学意义(P<0.05),B、C组之间无统计学差异(P>0.05)。手术时间(y)随着手术例数(x)的增加而减少[y=-10.243ln(x)±192.89,R2=0.637,P<0.001],并在B、C组达到相对稳定。三组置钉准确率、皮质接触层数无统计学差异(P>0.05)。术后6个月时腰痛VAS评分由术前4.8±0.7分降至1.9±0.6分(P<0.001),腿痛VAS评分由术前7.5±0.7分降至1.8±0.6分(P<0.001),JOA评分由术前11.3±1.8分升至23.3±1.6分(P<0.001)。随访期间41例发生融合,1例融合器移位,未出现螺钉松动和融合器沉降。结论:机器人辅助下CBT螺钉内固定术治疗腰椎退行性疾病置钉准确率高,确保螺钉与皮质之间充分接触,安全性高。随着手术例数的增加其手术时间以及出血量逐渐减少,并在15台后趋于稳定。

Objectives:To evaluate the accuracy of screw placement,the contact of cortex,and the learning curve of cortical bone trajectory(CBT)screw fixation technique assisted by orthopedic robot in lumbar degenerative diseases.Methods:The data of 45 patients with L4-5 degenerative disease treated with orthopedic surgical robot-"TiRobot"assisted CBT screw implantation from October 2019 to April 2021 were analyzed retrospectively.There were 27 males and 18 females,aged 64.3±6.9 years old,which included 8 cases of lumbar disc herniation,28 cases of lumbar spinal stenosis and 9 cases of degenerative spondylolisthesis.The patients were divided into three chronological groups of A,B and C according to the date of operation with 15 cases in each group.The operative time,the amount of bleeding,the scores of VAS and JOA before and at six months after surgery were collected,and the ln curve regression analysis was used to reflect the changing trend of operative time with the number of operation cases.The accuracy of screw placement and the number of contacted cortical bone layers were evaluated by CT after operation,and screw loosening,interbody fusion,and cage subsidence and migration were evaluated by X-ray and CT during follow-up.Results:All the patients completed the operation successfully.The operative time was 140-195min(163.5±11.3min)and the blood loss was 140-265ml(210.0±28.9ml).A total of 166 screws were implanted with an acceptance rate of 97%(161/166).The average total cortical contact layers and pedicle cortical contact layers were 4.9±0.6 and 3.3±0.6 respectively.The operative time and blood loss in groups B and C decreased compared with group A,and the differences were significant(P<0.05),while there was no statistical difference between groups B and C(P>0.05).The operative time(y)decreased with the increase of the number of cases(x)[y=-10.243ln(x)+192.89,R2=0.637,P<0.001],which reached a relatively stable level in groups B and C.There was no statistical difference in the screw placement accuracy and cortical contact layers among the three groups(P>0.05).At six months after surgery,the VAS score of low back pain decreased from 4.8±0.7 to 1.9±0.6(P<0.001),the VAS score of leg pain decreased from 7.5±0.7 to 1.8±0.6(P<0.001),and the JOA score increased from 11.3±1.8 to 23.3±1.6(P<0.001).During the follow-up period,interbody fusion occurred in 41 cases,while cage migration occurred in 1 case,and no screw loosening or cage subsidence were observed.Conclusions:Robot-assisted CBT screw fixation has a high screw placement accuracy in the treatment of lumbar degenerative diseases,which enjoys a high security through ensuring a full contact between screw and cortex.With the increase of the number of surgical cases,the operative time and the blood loss gradually decreases and tends to be stable after 15 cases.