New TINAVI robot-assisted technique safely, precisely places pedicle screw in spinal surgery

Zhang et al. conducted a study to determine the rates and risk factors of pedicle screw placement accuracy and the proximal facet joint violation (FJV) using TINAVI robot-assisted technique. The article has been published in Journal of Orthopaedic Surgery and Research.

Patients with thoracolumbar fractures or degenerative diseases were recruited for the study. The pedicle penetration and proximal FJV were compared in different instrumental levels to identify the safe and risk segments during insertion. Moreover, the factors were also assessed using univariate and multivariate analyses.

Robot assisted percutaneous insertion technique:

The percutaneous pedicle screw placements were performed with the TiRobot (TINAVI Medical Technologies Co. Ltd.) system composed of three basic elements: an optical tracking device, a workstation for preoperative planning and intraoperative controlling, and a robotic arm.

After general anesthesia with endotracheal intubation, the patient took the prone position. Then, the position plate was located and the projection of the planned vertical body pedicle on skin was marked. The pedicle screws were inserted in according with the original method under the guidance of TiRobot system. As for the patients suffering from fractures, the pedicle screw was inserted directly along the guide wire, and the incision was closed after the fracture rehabilitation performed with the screw rod. In contrast, regarding the patients suffering from the degenerative diseases, the screw is placed on the non-decompression side after the insertion of guide wire under the robotic guidance, whereas the trajectory of screw is prepared along the guide wire on the decompression side, and then, the screw is placed after transforaminal lumbar interbody fusion (TLIF).

The observations of study were:

• A total of 72 patients with 332 pedicle screws were included in the current study.

• The optimal and clinically acceptable screw positions were 85.8% and 93.4%.

• Of the 332 screws concerning the intra-pedicular accuracy, 285 screws (85.8%) were evaluated as Grade A according to the Gertzbein and Robbins scale, with the remaining 25 (7.6%), 10 (3.0%), 6 (1.8%), and 6 screws (1.8%) as Grades B, C, D, and E.

•In terms of the proximal FJV, 255 screws (76.8%) screws were assessed as Grade 0 according to the Babu scale, with the remaining 34 (10.3%), 22 (6.6%), and 21 screws (6.3%) as Grades 1, 2, and 3.

• The univariate analysis showed significantly higher rate of penetration for patients with age < 61 years old, sex of female, thoracolumbar insertion, shorter distance from skin to insertion point, and smaller facet angle.

• The patients with the sex of female, BMI< 25.9, grade I spondylolisthesis, lumbosacral insertion, longer distance from skin to insertion point, and larger facet angle had a significantly higher rate of proximal FJV.

• The outcomes of multivariate analyses showed that sex of male (adjusted OR 0.320, 95% CI 0.140–0.732; p=0.007), facet angle≥45° (adjusted OR 0.266, 95% CI 0.090–0.786; p=0.017), distance from skin to insertion point≥4.5 cm (adjusted OR 0.342, 95% CI 0.134–0.868; p=0.024), and lumbosacral instrumentation (adjusted OR 0.227, 95% CI 0.091–0.566; p=0.001) were independently associated with intra-pedicular accuracy; the L5 insertion (adjusted OR 2.020, 95% CI 1.084–3.766; p=0.027) and facet angle≥45° (adjusted OR 1.839, 95% CI 1.026–3.298; p=0.041) were independently associated with the proximal FJV.

The authors concluded that - TINAVI robot-assisted technique was associated with a high rate of pedicle screw placement and a low rate of proximal FJV. This technique showed a safe and precise performance for pedicle screw placement in spinal surgery.

Key Words: TINAVI, robot-assisted technique, proximal facet joint violation, Zhang et al, pedicle screw placement, Journal of Orthopaedic Surgery and Research

Further reading:

Safety and risk factors of TINAVI robot-assisted percutaneous pedicle screw placement in spinal surgery

Zhang et al

Journal of Orthopaedic Surgery and Research (2022) 17:379

https://doi.org/10.1186/s13018-022-03271-6