MAUDE Adverse Event Report: STRYKER GMBH CANNULATED SCREW, PARTIALLY THREADED ASNIS III Ø4.0X44MM TL15MM; SCREW, FIXATION, BONE

Catalog Number	604644S
Health Effect - Clinical Code	Device Embedded In Tissue or Plaque (3165)
Date of Event	01/31/2019
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
The reported event that cannulated screw, partially threaded asnis iii ø4.0x44mm tl15mm was alleged of 'implant breakage after surgery' could be confirmed.Based on investigation, the root cause was attributed to a user related issue.The failure was caused by too much torque being applied to the screw, while being extracted from the bone.The device inspection revealed the following: the product was returned and it was confirmed to be broken in two.Only the proximal part was returned.The screw head shows discoloration due to use, but doesn't show extensive damage.The breakage surface shows signs of over-torque, since the screw broke in spiral manner.Furthermore, the analysis of the breakage surface shows that the surface is brittle, which is characteristic of a fracture following the application of too big of a force.Such deformation indicates screw was over-torqued and twisted until breakage or solid screw driver was not used properly to extract the screw.Broken surface has marks in a rotating move, which means that it broke while being twisted.The screw shaft is twisted and broken.Threaded part of screw is missing (remain implanted in patient as per event description).The ifu clearly states that ¿ensure that you are familiar with the intended uses, indications/contraindications, compatibility and correct handling of the implant, which are described in the operative technique manual for the product system.' the implant extraction set states that ¿to avoid damaging the screw, make sure the screwdriver is in line with the screw axis and fully inserted.Never use a worn or damaged screwdriver to remove screws.It is recommended that the solid screwdriver be used for screw removal.Strong bone formation around the implant is possible in the pediatric cases using partially threaded screws.This may lead to difficult implant removal with an increased risk of screw head breakage or stripping of screw hexagonal head.¿ during the extraction, the screw was under high tension and combined with the rotational moves, this led to a torsional fracture.However, as explained in the memo (potential recurring situation identification - (b)(4) trending), ¿regardless of the implant size or type the torque needed to explant a screw can be higher than the torque needed to implant a screw.In some cases the torque required to remove the implant is higher than the mechanical properties of the screw.In these cases the implant breaks during explanation.Specific instruments dedicated for implant removal are offered by stryker to help explanation of screws.Stryker offers dedicated instrument sets (implant extraction set, modul i ref 1806-6150 and modul 2 ref 1806-6151).¿ by using these specific extraction sets, the removal of screws will be easier.A review of the device history for the reported lot did not indicate any abnormalities.No corrective actions are required at this time.A review of the labeling did not indicate any abnormalities.No indications of material, manufacturing or design related problems were found during the investigation.If any further information is provided, the investigation report will be updated.
Event or Problem Description
It was reported that on (b)(6) 2017, variax fibula plate and asnis 4.0 screw were implanted for right ankle joint.At (b)(6) 2019, although all devices were tried to be removed because bone fusion was confirmed, the screw was fractured about 5mm from the base of screw head.Therefore, the asnis screw was left in the patient body.The screw was removed with solid driver.
Event or Problem Description
It was reported that on (b)(6) 2017, variax fibla plate and asniss4.0 screw were implanted for right ankle joint.At (b)(6) 2019, although all devices were tried to be removed because bone fusion was confirmed, the screw was fractured about 5mm from the base of screw head.Therefore, the asniss screw was left in the patient body.The screw was removed with solid driver.

• Brand Name: CANNULATED SCREW, PARTIALLY THREADED ASNIS III Ø4.0X44MM TL15MM
• Common Device Name: SCREW, FIXATION, BONE
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; CH 2545
• MDR Report Key: 8375084
• Report Number: 0008031020-2019-00137
• Device Sequence Number: 16240655
• Product Code: HWC
• UDI-Device Identifier: 04546540089823
• UDI-Public: 04546540089823
• Combination Product (Y/N): N
• PMA/510(K) Number: K000080
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Device Implanted Year: 2017
• Device Explanted Year: 2019
• Reporter Type: Manufacturer
• Report Source: health professional
• Initial Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date (Section B): 03/21/2019

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: Lay User/Patient
• Device Expiration Date: 01/31/2019
• Device Catalogue Number: 604644S
• Device Lot Number: F04496
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 02/18/2019
• Initial Date Received by Manufacturer: 02/01/2019
• Supplement Date Received by Manufacturer: 02/25/2019
• Initial Report FDA Received Date: 02/27/2019
• Supplement Report FDA Received Date: 03/21/2019
• 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: Other
• Patient Age: 57 YR
• Patient Weight: 65