MAUDE Adverse Event Report: STRYKER SPINE-US OASYS BLOCKER; POSTERIOR CERVICAL SCREW SYSTEM

Model Number	48551000
Medical Device Problem Codes	Fracture (1260); Migration (4003)
Health Effect - Clinical Code	No Known Impact Or Consequence To Patient (2692)
Date of Event	10/13/2019
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
Device remains implanted.
Event or Problem Description
A physician reported that an oasys blocker construct failed post-operatively as seen on x-ray imaging.Revision surgery has not been reported.This record represents part 4 of 5.
Additional Manufacturer Narrative
Visual, dimensional, material and functional analysis could not be performed as the device was not returned.However, lateral x-ray images were provided.It can be seen that three blockers on the left hand side have migrated out of the tulips of their respective screws.The blocker of superior most screw, on the left hand side, appears to be loosened and no longer captures the rod.The screw implanted adjacent to the superior most screw has migrated, still connected to the rod.The blocker of this screw appears to be loosened as well.A review of the device history and complaint history records could not be performed as a valid lot code was not provided and could not be obtained.Per surgical technique: loosening of spinal fixation implants can occur.Early mechanical loosening may result from inadequate initial fixation, latent infection, premature loading of the prosthesis or trauma.Late loosening may result from trauma, infection, biological complications or mechanical problems, with the subsequent possibility of bone erosion, migration and/or pain.As these implants remain in the patient, a conclusive root cause could not be established as further inspection could not take place.Some of the possible root causes are below: 1) the blocker(s) may not have been tightened to the recommended 3nm; the audible click of the disposable audible torque wrench could have been overlooked.The migration of the blocker(s) would compromise the capture of the rod.The unfastened rod could have placed excessive force on adjacent levels in the construct which could have lead to successive migration/loosening of blockers and screw.2) the rod on the left side of the oasys construct may not have been properly seated in the tulips of the implanted screws, causing instability in the construct and successive migration/loosening upon post-op movement.
Event or Problem Description
A physician reported that an oasys blocker failed post-operatively as seen on x-ray imaging.The blocker disengaged from its respective screws.No revision is planned at this time.This record represents blocker 4 of 5.

• Brand Name: OASYS BLOCKER
• Common Device Name: POSTERIOR CERVICAL SCREW SYSTEM
• Manufacturer (Section D): STRYKER SPINE-US; 2 pearl court; allendale NJ 07401
• MDR Report Key: 9678433
• Report Number: 0009617544-2020-00017
• Device Sequence Number: 2773935
• Product Code: NKG
• UDI-Device Identifier: 04546540371508
• UDI-Public: 04546540371508
• Combination Product (Y/N): N
• Initial Reporter State: NJ
• Initial Reporter Country: US
• PMA/510(K) Number: K151755
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Reporter Type: Manufacturer
• Report Source: health professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 04/29/2020

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Model Number: 48551000
• Device Catalogue Number: 48551000
• Device Lot Number: UNKNOWN
• Was Device Available for Evaluation?: No
• Initial Date Received by Manufacturer: 01/13/2020
• Supplement Date Received by Manufacturer: 03/31/2020
• Initial Report FDA Received Date: 02/06/2020
• Supplement Report FDA Received Date: 04/29/2020
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1