MAUDE Adverse Event Report: ALPHATEC SPINE, INC. SET SCREW (TI-6AL-4V ELI); PEDICLE SCREW SYSTEM

Model Number 47127

Device Problem Loose or Intermittent Connection (1371)

Patient Problem No Information (3190)

Event Date 12/12/2018

Event Type  Injury  

Manufacturer Narrative

No evaluation possible at this time.The implants have not been returned nor has the identifying lot number been provided.Upon the receipt of additional information or the product in question, a follow-up report will be submitted.

Event Description

Ct images revealed migration of the set screws at the distal 4-levels of the arsenal spinal fixation construct.During the revision conducted on (b)(6) 2018, seven of eight set screws were found to be loose.All 8 screws at the distal end of the construct were removed and replaced with an alternative system.The remainder of the construct did not show any indication of an issue therefore the two systems were fastened via a rod-rod connector.The arsenal spinal fixation system was originally implanted (b)(6) 2017 in a patient with pseudo arthrosis.

Manufacturer Narrative

There were two additional set screws reported to have been loose.They are of the same product part number but contain a separate manufacturing lot number.· 7919703 manufactured 12/20/2016 an investigation of the returned set screws showed that the threads are not deformed which indicates the set screws had not been cross threaded.However, an evaluation of the bottom set screw surface revealed unusual wear marks.The bottom surface is the surface which interacts with the rod to create a stable construct, therefore the wear pattern on this surface may be indicative of the screw performance.The expected set screw bottom surface pattern is as hour glass wear pattern resulting from a fully tightened set screw, normal to rod, with distributed loading of the rod.The explant set screws show wear marks that are unevenly distributed which indicates a non-distributed loading condition.One of the set screw showed wear marks similar to a starburst pattern which indicates partial set screw back out.This starburst pattern being indicative of non-normal loading of the rod under a dynamic loading condition.Based on these findings, the explants indicate that set screw disengagement is a result of a non-distributed loading and non-normalized rod conditions at final lockdown.

• Brand Name: SET SCREW (TI-6AL-4V ELI)
• Type of Device: PEDICLE SCREW SYSTEM
• Manufacturer (Section D): ALPHATEC SPINE, INC.; 5818 el camino real; carlsbad CA 92008
• MDR Report Key: 8231402
• MDR Text Key: 132529349
• Report Number: 2027467-2018-00089
• Device Sequence Number: 1
• Product Code: NKB
• UDI-Device Identifier: 00840967124582
• UDI-Public: (01)00840967124582
• Combination Product (y/n): N
• PMA/PMN Number: K133221
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative
• Type of Report: Initial,Followup
• Report Date: 12/13/2018

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 01/09/2019
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: 47127
• Device Catalogue Number: 47127
• Device Lot Number: 7878903
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 01/14/2019
• Date Manufacturer Received: 12/13/2018
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Outcome(s): Required Intervention