This report is being submitted to provide additional information regarding a supplemental investigation conducted by alpahtec for identiti alif intraoperative graft bolt failures.The supplemental investigation was completed on 04-jan-2023.Corrected information: d5: health professional h6.Medical device problem code: 1069 additional information: h6: type of investigation: 4102, 3331, 10 investigation findings: 3243, 4248 investigation conclusion: 19, 61 additional information: the graft bolt is a component of the alphatec identiti alif standalone interbody system, which is an integrated intervertebral body fusion device for use in anterior lumbar interbody fusion (alif) procedures used in patients for treatment, not diagnosis.The distal portion of the graft bolt which was inserted through the screw hole of the spacer remains in the vertebral body.The proximal portion of the broken graft bolt was removed from the patient.It returned to alphatec for evaluation on 07/15/2022.The patient's medical history is unknown.No additional information was provided to alpahtec regarding this event.The event was evaluated, and it was determined to involve the malfunction of a alphatec device.There was no death or serious injury reported and no indication of a significant risk to public health.A distal portion of the graft bolt which was inserted through the screw hole of the spacer remains in the vertebral body of the patient.There was no report that this event required subsequent surgical intervention: however, if this event was to reoccur, subsequent surgical intervention may be required.Based on the information provided, alphatec determined this event is reportable to the fda under 21 cfr 803.Visual inspection reveals a shear break which occurred through the proximal-most fenestration of the graft bolt.This failure is consistent with similar occurrences observed in the supplemental investigation alphatec conducted for this failure mode.The investigation included simulated use activities to replicate failure modes in a controlled setting, both in cadavers and in solid rigid polyurethane foam ("bone foam") and conducted astm testing to benchmark failure torques and understand the potential of failure during reasonable use.Physical characterization and investigation were performed on complaint-related returned materials, where available.Additional testing was performed on material, not distributed, to replicate the failure.The graft bolt is designed to withstand an insertion torque consistent with on-trajectory insertion (40°) into a range of bone qualities representative of the patient population.Mechanical testing performed as a part of the root cause investigation for these reported intraoperative failures demonstrates that the device meets performance specifications required for this device.Both the torque required to fail the graft bolt in torsion and the load required to fail the graft bolt in cantilever bending are greater than those required to fail a more conventional screw common to interfixated lumbar interbody fusion procedures.The following conclusions of the graft bolt intraoperative failure were drawn from the results of the investigation: 1.The failures were not the result of manufacturing defects, as no manufacturing defects were identified in the device history review.2.The failures were not the result of normal use of the graft bolt as prescribed in the surgical technique.The graft bolt was successfully designed to withstand much greater torques than the insertion torque into normal bone; this is reflected in both the stimulated use activities and the various mechanical test conducted.3.The failures were not the result of a performance deficiency in the graft bolt as compared to a more conventional screw design; indeed, the graft bolt is comparable to a conventional screw in insertion torque and outperforms a conventional screw in torsional and bending failure modes.4.The failures were primarily caused by use error.Gross deviation from the prescribed graft bolt insertion trajectory caused the graft bolt to impinge on the posterior end of the medial screw hole or the posterior wall of the interbody spacer.The users then did not react to the increase in insertion torque as they would have with a conventional screw design.With the graft bolt engaged in the porous titanium of the interbody spacer, insertion torque could increase until failure torque for the graft bolt was reached, resulting in shear failure.As a result of the supplemental investigation, alphatec has implemented labeling changes in the surgical technique guide and the instructions for use, prescribing the use of hole preparation instruments, cautioning against off-trajectory insertion, and warning of potential device failure in off-trajectory insertion conditions.On (b)(6) 2023, a field bulletin was sent alphatec sales force and customer service notifying them of the changes.Labeling review: "warnings/cautions/precautions: care should be taken in performing screw hole preparation to facilitate a proper graft bolt insertion trajectory and implantation.Confirm under fluoroscopy that the graft bolt insertion angle is as close as possible to a 40° trajectory.A shallow or incorrect graft bolt trajectory may result in encroachment of the spacer and lead to graft bolt breakage." on -05-dec-2022, the fda sent alphatec additional information request for this mdr.Alphatec responded to the fda on 13-jan-2023.
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