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B2, h1: a risk to the patient's health could not be excluded for these specific circumstances, since pilot holes, k-wires and screws were placed in the patient's spine in a different position than desired with navigation involved, despite according to the surgeon (treating clinician): the deviations of the placements of the one spine screw were detected by the surgeon with intra-operative c-arm imaging, and the screw placement was corrected to its intended position at the very same surgery with navigation.The outcome of the surgery was successful as intended, with all spine screw placements correct at the end of the surgery.There was no harm nor negative effect to the patient resulting due to the deviating placements, also not due to surgery/anesthesia prolongation of ca.30min.There were further no remedial actions for the patient done, necessary or planned.Hospitalization was also not prolonged.H6: according to the results of the brainlab investigation and the information provided by the hospital, it can be concluded that the root cause of the pilot hole and screw placed in vertebra left l2 with the aid of navigation, deviating at two attempts by ca.3mm, is: movements of the spine anatomy operated on (l2) during the surgery, in relation to the fixation location of the navigation reference array (right iliac crest) of the reference system, due to an insufficiently rigid connection of the anatomy in between, and the forces applied to the bone during instrumentation.Imaging data provided for this surgery show that a significant movement of the l2 anatomy had occurred, visible in between the pre-placement and post-placement scans for both affected attempts.Whereas the visible anatomy movement for the first attempt might have been amplified by the decompression performed afterwards, it demonstrates the non-rigid connection of the l2 anatomy, and the anatomical difference visible for the second attempt (with both scans after the decompression, only the second screw placement attempt occurring in between these scans), re-enforces that anatomical movement due to the not sufficient rigidity for the instrumentation forces had also occurred during the first affected screw placement attempt.Multi-level navigation - i.E.Operating on a different vertebra than the one the patient reference array for navigation is fixated to or operating across multiple vertebrae without remounting the patient reference and reregistering - especially if the connection in between the vertebrae is not rigid - results in relative movements of the vertebrae (actual anatomy) during the surgery that cannot be compensated by the navigation software displaying instrument positions on the registered pre-placement patient image scan.Apparently, the resulting deviation of the anatomy locations displayed by the navigation compared to the actual patient anatomy locations during the placements, was not recognized by the user with the necessary and required navigation accuracy verification throughout the surgery, before significant invasive actions and at any time significant forces were applied.There is no indication of a systematic error or malfunction of the brainlab device (navigation).Corresponding brainlab measures to minimize this anticipated risk as low as reasonably practicable are already in place.H7: brainlab intends to re-iterate the relevant topics regarding the use of the device to this customer.
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A minimally invasive surgery on the lumbar spine for a prone transpsoas (ptp) fusion of vertebrae l2 to l5 - including placements of ptp cages and extending a pre-existent fusion l3/l4, due to adjacent segment degeneration l2/l3 and l4/l5 - with intended placement of 8 spine screws bilateral, was performed with the aid of the brainlab spine & trauma navigation 3.0.After placing the 8 spine screws with navigated instruments, the surgeon determined from intra-operative c-arm imaging, that 1 of the screws - at vertebra left l2 - deviated from its intended position shifted by ca.3mm medially and superiorly.The surgeon decided to remove this one deviating screw and to re-place it with the same navigated method as before - resulting in a deviation from its intended position shifted by again ca.3mm, this time laterally and inferiorly, as determined from another intra-operative verification c-arm scan.The surgeon removed this screw again and re-placed it with navigation to its correct position at the very same surgery.According to the surgeon (treating clinician): the outcome of the surgery was successful as intended, with all spine screw placements correct at the end of the surgery.There was no harm nor negative effect to the patient resulting due to the deviating placements, also not due to surgery/anesthesia prolongation of ca.30min.There were further no remedial actions for the patient done, necessary or planned.Hospitalization was also not prolonged.
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