MAUDE Adverse Event Report: STRYKER SPINE-US OASYS 4.0 X 24MM PA SCREW MEDIAL; POSTERIOR CERVICAL SCREW SYSTEM

Model Number	48555424
Medical Device Problem Codes	Material Separation (1562); Device Dislodged or Dislocated (2923)
Health Effect - Clinical Codes	Dysphagia/ Odynophagia (1815); Injury (2348)
Date of Event	03/26/2020
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that an oasys polyaxial screw tulip disengaged post-operatively.X-rays confirmed that the screw head had come off and the ideal alignment had been lost.Revision surgery was performed to re-install the rod for correction.The surgeon removed the disengaged screw, then replaced it with a screw that was one size longer.
Additional Manufacturer Narrative
B.5.Has been corrected to include "possible dysphagia." updated d.6.With implant date.
Event or Problem Description
It was reported that an oasys polyaxial screw tulip disengaged post-operatively.X-rays confirmed that the screw head had come off and the ideal alignment had been lost.It was additionally reported that the patient experienced "possible dysphagia".Revision surgery was performed to re-install the rod for correction.The surgeon removed the disengaged screw, then replaced it with a screw that was one size longer.It is unknown if the patient is still experiencing dysphagia.
Additional Manufacturer Narrative
D.10 was updated to reflect product return.Visual inspection: the screw was returned with the tulip disengaged from the shank.There was slight deformation on the bottom of the tulip in a singular direction, where the tulip disengaged from the shank.The returned shank had a witness mark from the rod.The size of the witness mark indicates excessive force applied to the screw while tightening.There was also deformation found on the tulip threading that is consistent with cross threading or misalignment of the blocker.The returned blocker also had its inner hex stripped, which can be a result of over tightening.Device history records were reviewed an no relevant manufacturing issues or similar complaints were identified.Based on inspection of the returned screw and what was reported by the sales rep, the most likely root cause is excessive force applied to the blocker during tightening.There is indication that the blocker may have been misaligned with the tulip, most likely due to the tight surgical space the surgeon was working within, which would have caused more force to be applied eventually causing the tulip to disengage.
Event or Problem Description
It was reported that an oasys polyaxial screw tulip disengaged post-operatively.X-rays confirmed that the screw head had come off and the ideal alignment had been lost.It was additionally reported that the patient experienced "possible dysphagia".Revision surgery was performed to re-install the rod for correction.The surgeon removed the disengaged screw, then replaced it with a screw that was one size longer.It is unknown if the patient is still experiencing dysphagia.

• Brand Name: OASYS 4.0 X 24MM PA SCREW MEDIAL
• Common Device Name: POSTERIOR CERVICAL SCREW SYSTEM
• Manufacturer (Section D): STRYKER SPINE-US; 2 pearl court; allendale NJ 07401
• MDR Report Key: 9991050
• Report Number: 0009617544-2020-00067
• Device Sequence Number: 4355763
• Product Code: NKG
• UDI-Device Identifier: 04546540469625
• UDI-Public: 04546540469625
• Combination Product (Y/N): N
• PMA/510(K) Number: K151755
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2020
• Device Explanted Year: 2020
• Reporter Type: Manufacturer
• Report Source: health professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup,Followup
• Report Date (Section B): 07/28/2020

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Model Number: 48555424
• Device Catalogue Number: 48555424
• Device Lot Number: 190660
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 05/28/2020
• Initial Date Received by Manufacturer: 03/26/2020
• Supplement Date Received by Manufacturer: 04/27/2020; 06/29/2020
• Initial Report FDA Received Date: 04/23/2020
• Supplement Report FDA Received Date: 05/13/2020; 07/28/2020
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Required Intervention