MAUDE Adverse Event Report: STRYKER GMBH CANNULATED SCREW, PARTIALLY THREADED ASNIS III 4.0X65MM TL22MM; SCREW, FIXATION, BONE

Model Number	325065S
Medical Device Problem Code	Fracture (1260)
Health Effect - Clinical Code	Device Embedded In Tissue or Plaque (3165)
Date of Event	06/05/2020
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
The customer reported : "these screws were placed in the patient on (b)(6) 2019 at the level of the medial malleolus.The two screws were removed on (b)(6) 2020.The first screw was extracted without any problem.However, during the extraction of the second screw, the pre-threaded axis twisted and prevented its removal.An attempt was made to extract the screw with a strong pair of pliers and then with a trephine, which allowed the pre-threaded bone core to be removed without allowing the screw to be removed in reverse.Part of the screw is left intraosseous.Unfortunately, the reference of the broken screw could not be precisely identified (it's either a debris from ref 325065s or from ref 325060s).
Additional Manufacturer Narrative
The reported event that cannulated screw, partially threaded asnis iii ø4.0x65mm tl22mm was alleged of 'implant - extraction impaired' could be confirmed.The device inspection revealed the following: the product was returned and is indeed broken in at least three parts.Two out of the three were returned, in addition to a bone remain cylinder, maybe including a piece of the screw.The returned screw is highly twisted proving that high torsional loads were applied to it.Considering that the patient was only 17 at the time of the event, very hard bone and a high osseointegration between the screw and the bone can be considered the root cause of the inability to extract the device out of the patient.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, ¿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, moduli ref (b)(4) and modul 2 (b)(4) ).¿.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
The customer reported : "these screws were placed in the patient on (b)(6) 2019 at the level of the medial malleolus.The two screws were removed on (b)(6) 2020.The first screw was extracted without any problem.However, during the extraction of the second screw, the pre-threaded axis twisted and prevented its removal.An attempt was made to extract the screw with a strong pair of pliers and then with a trephine, which allowed the pre-threaded bone core to be removed without allowing the screw to be removed in reverse.Part of the screw is left intraosseous.Unfortunately, the reference of the broken screw could not be precisely identified (it's either a debris from ref (b)(4) or from ref (b)(4)).

• Brand Name: CANNULATED SCREW, PARTIALLY THREADED ASNIS III 4.0X65MM TL22MM
• Common Device Name: SCREW, FIXATION, BONE
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; CH 2545
• MDR Report Key: 10217976
• Report Number: 0008031020-2020-01817
• Device Sequence Number: 16712565
• Product Code: HWC
• UDI-Device Identifier: 07613327076295
• UDI-Public: 07613327076295
• Combination Product (Y/N): N
• Initial Reporter Country: FR
• PMA/510(K) Number: K000080
• Number of Events Summarized: 1
• Summary Report (Y/N): N
• Reporter Type: Manufacturer
• Report Source: health professional
• Initial Reporter Occupation: Risk Manager
• Type of Report: Initial,Followup
• Report Date (Section B): 08/04/2020

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this a Product Problem Report?: Yes
• Operator of Device: Health Professional
• Device Expiration Date: 08/31/2022
• Device Model Number: 325065S
• Device Catalogue Number: 325065S
• Device Lot Number: L27957
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 06/23/2020
• Initial Date Received by Manufacturer: 06/08/2020
• Supplement Date Received by Manufacturer: 07/09/2020
• Initial Report FDA Received Date: 07/01/2020
• Supplement Report FDA Received Date: 08/04/2020
• Is This a Single-Use Device that was Reprocessed and Reused on a Patient? (Y/N): No
• Patient Sequence Number: 1
• Patient Age: 17 YR
• Patient Weight: 75