[Learning curve of minimally invasive pedicle screw placement]

Image Guided Interpedicular Screw Placement Simulation System for Training and Skill Evaluation. Proof of Concept

BACKGROUND

The SpineST-01 system is an image-guided vertebrae cannulation training system. During task execution, the computer calculates performance-based metrics displaying different visual perspectives (lateral view, axial view, anteroposterior view) with the position of the instrument inside the vertebra. Finally, a report with the metrics is generated as performance feedback.

METHODS

A training box holds a 3D printed spine section. The computer works with 2 orthogonally disposed cameras, tracking passive markers placed on the instrument. Eight metrics were proposed to evaluate the execution of the surgical task. A preliminary study with 25 participants divided into 3 groups (12 novices, 10 intermediates, and 3 expert) was conducted to determine the feasibility of the system and to evaluate and assess the performance differences of each group using Kruskal-Wallis analysis and Mann-Whitney U analysis. In both analyses, a P value ≤ 0.05 was considered statistically significant.

RESULTS

When comparing experts versus novices and all 3 groups, statistical analysis showed significant differences in 6 of the 8 metrics: axial angle error (°), lateral angle error (°), average speed (mm/second), progress between shots (mm), Time (seconds), and shots. The metrics that did not show any statistically significant difference were time between shots (seconds), and speed between shots (mm/second). Also, the average result comparison placed the experts as the best performance group.

CONCLUSIONS

Initial testing of the SpineST-01 demonstrated potential for the system to practice image-guided cannulation tasks on lumbar vertebrae. Results showed objective differences between experts, intermediates, and novices in the proposed metrics, making this system a feasible option for developing basic navigation system skills without the risk of radiation exposure and objectively evaluating task performance.

20 Tips to Avoid and Handle Problems in the Placement of Percutaneous Pedicle Screws

BACKGROUND

Two-dimensional fluoroscopy-guided percutaneous pedicle screw placement is currently the most widely applied instrumentation for minimally invasive treatment of spinal injuries requiring stabilization. Although this technique has advantages over open instrumentation, it also presents new challenges and specific complications. The objective of this study was to provide recommendations developed from the experience of several spinal surgeons at different minimally invasive spine surgery reference centers to solve specific problems and prevent complications during the learning curve of this technique.

METHODS

An AO Spine Latin America minimally invasive spine surgery study group analyzed the most frequent complications and challenges occurring during the placement of >14,000 two-dimensional fluoroscopy-guided percutaneous pedicle screws at different centers over 15 years. Twenty tips considered most relevant to performing this technique, excluding problems directly related to specific brands of instruments, were presented.

RESULTS

The 20 tips included the following: (1) positioning; (2) clean and painless; (3) fewer x-rays; (4) check the clock; (5) beveled tip; (6) transverse-rib-pedicle; (7) double Jamshidi; (8) hammer the Kirschner wire; (9) bent tip; (10) too loose, too tight; (11) new trajectory; (12) manual control; (13) start over; (14) Kirschner wire first; (15) adhesive drape control; (16) bend the rod; (17) lower rods; (18) freehand inner; (19) posterior fusion; (20) revision.

CONCLUSIONS

Implementation of these tips might improve performance of this technique and reduce the complications related to percutaneous pedicle screw placement.

Robot-assisted percutaneous vertebroplasty under local anaesthesia for osteoporotic vertebral compression fractures: a retrospective, clinical, non-randomized, controlled study

RESEARCH AND DESIGN

A retrospective, clinical, non-randomized, controlled study.

OBJECTIVE

To evaluate the application of a new spinal navigation robot on percutaneous vertebroplasty (PVP) under local anaesthesia.

METHODS

The result of inserting the puncture needle into the simulated pedicle was observed in vitro. Thirty patients with thoracolumbar fractures were enrolled. The basic data, operation-related data and clinical effect scores were recorded. The learning curve of robot-guided surgery was analysed.

RESULTS

The maximum yaw angle of the puncture needle implanting into the simulated pedicle is 0.5°. The operation time (33.93 ± 5.97 min vs. 53.75 ± 14.08 min, p = 0.000) and the average X-ray exposure time (31.43 ± 4.93 s vs. 54.69 ± 2.15 s, p = 0.000) was significantly less in the robot group. The surgeons quickly mastered the technique of robot-guided pedicle puncture after three surgeries.

CONCLUSIONS

Robot-assisted PVP could performed under local anaesthesia with the new robot.