Batch review performed on 28 november 2019.Lot 1922393: (b)(4) items manufactured and released on 05-sep-2019.Expiration date: 2024-07-27.No anomalies found related to the problem.To date, (b)(4) items of the same lot have been already sold without any similar reported event.Preliminary investigation performed by r&d project manager from the picture attached in the complaint and by the description of the event, it's possible to see that the head is broken.This event occurred during the tightening of the screw into the vertebral body.The total length of the broken piece is approximately 7-8mm, this means that in the bone and plate there are fixed 22-23mm of the screw.It's not clear from the event description which instruments have been used for the screw hole preparation: awl, drill, tap etc.Neither which instruments have been used for the screw insertion.In addition, it could be helpful to know in which level (i.E.L5) and in which direction (cranial/caudal) the surgeon was tightening the screw.Despite of the missing information that it's possible to collect before the visual inspection, it's possible to expect that the root cause of the event is the application of a huge or uncontrolled torsion on the screw, above 7nm (see report 167_120807_120_297-rev0).As additional information, for the fixation of the screw, it has to be applied a torsion of 5nm (+/-10%) with a specific torque limiter available in the set.Despite the missing piece of the screw, the fixing mechanism is not compromised.In fact, the plate is threaded and there is no risk of screw migration.Preliminary investigation performed on (b)(6) 2019.
|
During the primary spine surgery, while the surgeon was inserting screws and driving the screw down with the driver, the screw broke.The surgeon was able to remove the head of the screw, however, the other half is stuck in the patient's bone.There was a 10-minute delay and the surgery was completed successfully.
|