MAUDE Adverse Event Report: SYNTHES MEZZOVICO 2.0MM IMF SCREW SELF-DRILLING 8MM; SCREW, FIXATION

Catalog Number 201.928S

Device Problem Break (1069)

Patient Problems No Known Impact Or Consequence To Patient (2692); Device Embedded In Tissue or Plaque (3165)

Event Date 02/25/2014

Event Type  malfunction  

Event Description

Intermaxillary fixation screw broke on insertion, half remained in the patient and half recovered (screw head) and returned for analysis.Surgeon noted that nothing was unusual regarding the bone quality and it wasn¿t a situation where he would expect to have to pre drilled.Update (b)(6) 2014: only one screw is broken.There was no patient harm.This is report 1 of 1 for (b)(4).

Manufacturer Narrative

Part was received and is being evaluated and a lot number is being reported.A review of the device history revealed no ncrs were generated during production.Review of the device history record of the corresponding non-sterile part 201.928 lot 8597921 showed that there were no issues during the manufacture of the product that would contribute to this complaint condition.This device was used for treatment and not diagnosis.If information is obtained that was not available for the initial medwatch, a follow-up medwatch will be filed as appropriate.

Manufacturer Narrative

Additional narrative: a manufacturing evaluation was conducted.The report indicates that lack of the threaded shaft it was not possible to measure the main features of the complained screw relevant for the issue under investigation.The other 3 screws of the same lot returned were measured and found within specification.On the basis of the analysis of the 3 unbroken screws the lot 8597921 is conforming from a manufacturing perspective.The conclusion of the product investigation is that there is no evidence of nonconformances manufacturing related.Device was used for treatment, not diagnosis.If information is obtained that was not available for the initial medwatch, a follow-up medwatch will be filed as appropriate.

Manufacturer Narrative

Additional narrative: device was used for treatment, not diagnosis.An additional manufacturing evaluation was completed: four intermaxillary fixation (imf) screws were sent to investigation, three of them were in the original packaging and not damaged, one of the imf screws was broken.Macroscopic assessment revealed at the broken screw a fracture surface at the first convoluted close to the screw head.Tissues and/or bone residues could be documented at the thread close to the fracture area, the slots and the transversal holes were not damaged or deformed, and it is likely that the screws correctly connected to the screwdriver.Macroscopic assessment of the fracture surface revealed a not damaged fracture area with a plastically deformed first convolution from the thread.The examination by scanning electron microscope (sem) revealed torsional deformation lines on the entire fracture areas at the broken screw and bone and tissues residues, at higher magnification dimple structure in a preferred direction could be documented, an unequivocal indication of a ductile forced fracture mechanism under torsional load.The microstructure of the used material was examined in a cross section and found to be according to the standards.There were no evident irregularities or signs of embrittlement.The screws are manufactured from stainless steel, which is specified as surgical implant material in the standard iso 5832-1, the astm standard f-138 and f139.From the article number together with the fabrication lot number, we can trace the production records as well as the implant material lot, its intense and systematic material acceptance testing and was released for manufacturing only after compliance with the specifications had been established.The investigation performed could not detect any material faults.The imf screw broke according to a ductile forced fracture mechanism.The fine dimple structure on the entire fracture surface is a clear indication of a ductile forced fracture.It is likely the screw was overloaded i the axial direction.If information is obtained that was not available for the initial medwatch, a follow-up medwatch will be filed as appropriate.

Manufacturer Narrative

Additional narrative: a pd event evaluation was conducted.The report indicates test report mt01-161 showed a safety factor of 1.5 between failure torque and maximum insertion torque for the 12mm long version of the stainless steel imf screw (201.932).Estimated occurrence rate determined to be 0.03%.Pd investigation result: indeterminate.Device was used for treatment, not diagnosis.If information is obtained that was not available for the initial medwatch, a follow-up medwatch will be filed as appropriate.

• Brand Name: 2.0MM IMF SCREW SELF-DRILLING 8MM
• Type of Device: SCREW, FIXATION
• Manufacturer (Section D): SYNTHES MEZZOVICO; zona industriale 4; mezzovico CH68 05; SZ CH6805
• Manufacturer (Section G): SYNTHES MEZZOVICO; zona industriale 4; mezzovico CH68 05; SZ CH6805
• Manufacturer Contact: linda plews ; 1302 wrights lane east; west chester, PA 19380 ; 6107195000
• MDR Report Key: 3697425
• MDR Text Key: 4253234
• Report Number: 1000562954-2014-10028
• Device Sequence Number: 1
• Product Code: DZL
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: PK010527
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Foreign,Health Professional,Company Representative
• Reporter Occupation: Health Professional
• Type of Report: Initial,Followup,Followup,Followup
• Report Date: 02/25/2014

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 03/25/2014
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Expiration Date: 09/01/2023
• Device Catalogue Number: 201.928S
• Device Lot Number: 8643793
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 03/04/2014
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 11/17/2014
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 09/05/2013
• Is the Device Single Use?: Yes
• Type of Device Usage: Unknown
• Patient Sequence Number: 1