A comparative study on treatment of lumbar degenerative disease with osteoporosis by manual and robot-assisted cortical bone trajectory screws fixation

Abstract

To compare the safety and accuracy of manual and robot-assisted cortical bone trajectory (CBT) screws fixation in the treatment of lumbar degenerative diseases with osteoporosis. The clinical data of 58 cases of lumbar degenerative disease with osteoporosis treated by CBT screw fixation between February 2017 and February 2019 were analyzed retrospectively. Among them, 29 cases were fixed with CBT screws assisted by robot (group A), 29 cases were fixed with CBT screws by hand (group B). There was no significant difference between the two groups in terms of gender, age, body mass index, lesion type, T-value of bone mineral density, and operative segment ( P>0.05), with comparability. The accuracy of implant was evaluated by Kaito's grading method, and the invasion of CBT screw to the superior articular process was evaluated by Babu's method. The operation time and intraoperative blood loss in group A were significantly less than those in group B ( t=-8.921, P=0.000; t=-14.101, P=0.000). One hundred and sixteen CBT screws were implanted in the two groups. At 3 days after operation, according to the Kaito's grading method, the accuracy of implant in group A was 108 screws of grade 0, 6 of grade 1, and 2 of grade 2; and in group B was 86 screws of grade 0, 12 of grade 1, and 18 of grade 2; the difference was significant ( Z=4.007, P=0.000). There were 114 accepted screws (98.3%) in group A and 98 (84.5%) in group B, the difference was significant ( χ 2=8.309, P=0.009). At 3 days after operation, according to Babu's method, there were 85 screws in grade 0, 3 in grade 1, and 2 in grade 2 in group A; and in group B, there were 91 screws in grade 0, 16 in grade 1, 5 in grade 2, and 4 in grade 3; the difference was significant ( Z=7.943, P=0.000). No serious injury of spinal cord, nerve, and blood vessel was found in the two groups. One patient in group A had delayed cerebrospinal fluid leakage, and 2 patients in group B had mild anemia. Both groups were followed up 10-14 months (mean, 11.6 months). The neurological symptoms were improved, and no screw loosening or fracture was found during the follow-up. Compared with manual implantation of CBT screw, robot-assisted spinal implant has higher accuracy, lower incidence of invasion of superior articular process, and strong holding power of CBT screw, which can be applied to the treatment of lumbar degenerative diseases with osteoporosis.