Visual, dimensional, material and functional analysis could not be performed as the device was not returned.However, post-op x-rays were provided showing 2 rods and 4 blockers migrated out of the screw.Device and complaint history records review could not be performed as a valid lot code was not provided and could not be obtained.It was reported that during implantation, screws did not give enough polyaxiality and the surgeon needed to compresses.Surgeon over tightened and feels this was an issue with over compressing.Per the surgical technique, once the correction procedures have been carried out and the spine is fixed in a satisfactory position, the final tightening of the blockers is done by utilizing the anti-torque key and the torque wrench.The torque wrench indicates the appropriate torque that has to be applied to the implant for final tightening.Line up the arrow to the line in order to achieve this final tightening torque of 8 nm.During final tightening, 8 nm must not be exceeded.It was also reported that the patient did not fuse.Per the surgical technique, inappropriate or improper surgical placement of this device may cause distraction or stress shielding of the graft or fusion mass.This may contribute to failure of an adequate fusion mass to form.The root cause of the reported event is multifactorial and includes: overtightening of the blockers; surgeon applied too much force to the spine during compression; pseudarthrosis.
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