MAUDE Adverse Event Report: STRYKER GMBH CANNULATED SCREW, PARTIALLY THREADED ASNIS III 4.0X55MM TL18.5MM; SCREW, FIXATION, BONE

Model Number	604655
Medical Device Problem Code	Fracture (1260)
Health Effect - Clinical Code	No Clinical Signs, Symptoms or Conditions (4582)
Date of Event	11/24/2020
Type of Reportable Event	Malfunction
Additional Manufacturer Narrative
Upon completion of investigation, additional information will be provided in a supplemental report.
Event or Problem Description
"as reported: a (b)(6) year old male patient underwent orif of the fifth metatarsal bone (left side) with asnis as the initial operation on (b)(6) 2020.On (b)(6) 2020, when asnis 4.0 was going to remove from the patient body, the head of asnis was broke.Then when it was attempted to removed with the crown reamer, the shaft part broke.".
Additional Manufacturer Narrative
The reported event could be confirmed, since the device was returned for evaluation and matches the alleged failure mode.The device inspection revealed the following: the returned cannulated screw was found to be broken with its head completely sheared off clean from the shaft.The screw shaft was also found to be severely damaged and twisted, with the threaded portion broken off.The distal portion was the worst affected with a portion of the surface missing, indicating towards an enormous force applied to extract the screw.The cannulation was found to be completely deformed.The inner hex of the screw head was also deformed.Such deformation of hexagon and twisting of shaft indicates application of excessive torque on the screw and also that the solid screwdriver was not used properly to extract the screw.A review of the device history for the reported lot did not indicate any abnormalities.No corrective actions are required at this time.No indications of material, manufacturing or design related problems were found during the investigation.A review of the labeling did not indicate any abnormalities.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, ¿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 implant extraction sets.By using these specific extraction sets, the removal of screws will be easier.Based on investigation, the root cause was attributed to a user related issue.The failure was caused due to application of too much torque to the screw, while extracting from the bone.If any additional information is provided, the investigation will be reassessed.
Event or Problem Description
"as reported: a 18-year old male patient underwent orif of the fifth metatarsal bone (left side) with asnis as the initial operation on (b)(6)-2020.On (b)(6)2020, when asnis 4.0 was going to remove from the patient body, the head of asnis was broke.Then when it was attempted to removed with the crown reamer, the shaft part broke.".

• Brand Name: CANNULATED SCREW, PARTIALLY THREADED ASNIS III 4.0X55MM TL18.5MM
• Common Device Name: SCREW, FIXATION, BONE
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; SZ 2545
• MDR Report Key: 11066955
• Report Number: 0008031020-2020-02587
• Device Sequence Number: 11422139
• Product Code: HWC
• UDI-Device Identifier: 04546540089878
• UDI-Public: 04546540089878
• Combination Product (Y/N): N
• Initial Reporter Country: JA
• PMA/510(K) Number: K000080
• 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
• Report Date (Section B): 02/02/2021

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 Expiration Date: 07/31/2023
• Device Model Number: 604655
• Device Catalogue Number: 604655
• Device Lot Number: Y26585
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 12/23/2020
• Initial Date Received by Manufacturer: 11/24/2020
• Supplement Date Received by Manufacturer: 01/08/2021
• Initial Report FDA Received Date: 12/23/2020
• Supplement Report FDA Received Date: 02/02/2021
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Patient Age: 18 YR
• Patient Weight: 90