MAUDE Adverse Event Report: K2M, INC. POLYAXIAL SCREW; SIZE Ø3.5X16 MM; POSTERIOR CERVICAL SCREW SYSTEM

Model Number	7601-03516
Medical Device Problem Code	Mechanical Jam (2983)
Health Effect - Clinical Code	Bone Fracture(s) (1870)
Date of Event	02/26/2022
Type of Reportable Event	Serious Injury
Event or Problem Description
It was reported that approximately 5 months post-operatively, revision surgery was performed to address an unknown mispositioned screw.During this procedure it was discovered that the head of a yukon screw could not be moved.The yukon screw was then removed which caused damage to the massa lateralis.Surgery was successfully completed with a 4 minute surgical delay.This report captures the yukon screw.
Event or Problem Description
It was reported that approximately 5 months post-operatively, revision surgery was performed to address an unknown mispositioned screw.During this procedure it was discovered that the head of a yukon screw could not be moved.The yukon screw was then removed which caused damage to the massa lateralis.Surgery was successfully completed with a 4 minute surgical delay.This report captures the yukon screw.
Additional Manufacturer Narrative
Visual inspection showed the screw to be in fair condition, with some abrasive damage on the shank threads from removal.The tulip head was immobilized at approximately a 45° angle with respect to the screw shank.When the screw ball was examined from above through the opening in the base of the tulip, the helical grooves on the ball of the screw were deformed at the top of the ball near the hexalobe feature.This damage to the helical grooves likely contributed to the immobility of the screw head and was most likely caused by force exerted on the ball by the screw anvil when the rod was tightened into place during the initial surgery.Functional inspection was conducted by attempting to move the screw ball within the tulip head.The screw head was jammed in position and could not be forced loose.Due to this, the screw cannot be used as intended.The jam renders the screw hexalobe inaccessible and therefore, the implant could not be removed with an inserter.Device and complaint history records were reviewed for this lot and catalog number, no relevant manufacturing issues or adverse trends were identified.The most likely root cause of the screw head immobilization is the force exerted on the screw ball during final tightening in the initial surgery.Though the immobilization of the tulip made removal difficult, the screw had functioned as intended.Typically, a screw is inserted into the bone, a rod is placed, and a set screw is tightened into the screw head to secure the rod within the tulip.The rod creates an applied force against the anvil component of the screw, which forces the ball of the screw shank lower in the tulip.This creates a wedged condition in which the tulip is no longer posable around the ball of the screw.This feature is designed to reinforce the construct and provide stability in the patient.

• Brand Name: POLYAXIAL SCREW; SIZE Ø3.5X16 MM
• Common Device Name: POSTERIOR CERVICAL SCREW SYSTEM
• Manufacturer (Section D): K2M, INC.; 600 hope parkway se; leesburg VA 20175
• Manufacturer (Section G): K2M, INC.; 600 hope parkway se; leesburg VA 20175
• Manufacturer Contact: rita karan ; 2 pearl court; allendale, NJ 07401 ; 2017608000
• MDR Report Key: 14464937
• Report Number: 3004774118-2022-00198
• Device Sequence Number: 4685650
• Product Code: NKG
• UDI-Device Identifier: 10888857349322
• UDI-Public: 10888857349322
• Combination Product (Y/N): N
• Initial Reporter Country: GM
• PMA/510(K) Number: K171444
• 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): 09/07/2022

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: 7601-03516
• Device Catalogue Number: 7601-03516
• Device Lot Number: 23AX
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Is the Reporter a Health Professional?: Yes
• Type of Report(Section G): Initial
• Initial Date Received by Manufacturer: 05/09/2022
• Supplement Date Received by Manufacturer: 08/08/2022
• Initial Report FDA Received Date: 05/21/2022
• Supplement Report FDA Received Date: 09/07/2022
• Was Device Evaluated by Manufacturer? (Y/N): Yes
• Date Device Manufactured: 10/21/2021
• Is the Device Labeled for Single Use? (Y/N): Yes
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Usage of Device: Initial
• Patient Sequence Number: 1
• Outcome Attributed to Adverse Event: Other; Required Intervention
• Patient Sex: Unknown