A medtronic representative went to the site to test the equipment.The surgical arm passed a built in self test, advanced accuracy, stress, and trajectory tests.The system then passed the system checkout and was found to be fully functional.Analysis of the software exports and logs found the complaint was confirmed.Clinical export data file was thoroughly inspected.The log file was examined with respect to all intraoperative images in order to inspect and understand procedure workflow.Analysis reviewed the planning made for the case and the planning made in the or.No evidence of lateral or medial skiving potential was found.Analysis reviewed the matching accuracy of the system.The ct-fluoro matching of the vertebrae were determined acceptable with green values.Post-op image provided show left screw to be lateral to plan outside of the vertebral body, and right screw to be translated approximately 10 mm medial to plan.Post-op images provided show screws to be lateral and inferior to plan.As l1 trajectories were the only trajectories executed, platform or patient shift cannot be ruled out.Trauma fractures and presumably ligament raptures can be observed in l2 and l3.Mounting on a fractured spine may compromise the stability of the platform.According to the rep the platform used was "the single sp clamp out of the older bone mount tray.The one that tightens with a wing nut." intra-op scan shows the clamp used was the mis clamp.The mini clamp is designated to be attach to the mist or link bridge with further anchoring to the spine (and not separately).A schanz bond (can be seen in the 3d reconstruction) is for the schanz screw.Such platform assembly is not recommended.Furthermore, sizes are specifically fit for each platform assembly to assure best stability, connecting them otherwise may lead to platform instability.The system completed a bist test successfully before the surgery, and a full system check was performed.Analysis reviewed all the available information and concluded the root cause of the deviations of left and right l1 to be a platform shift due to the unstable anatomy on which the platform was mounted, combined with an incorrect selection and assembly of platform.Mounting the system onto a mobile spine due to significant axial fractures with presumed ligamentous injuries, combined with the use of the mini-clamp led to an unstable platform which moved whenever a slight force was used.If information is provided in the future, a supplemental report will be issued.
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