MAUDE Adverse Event Report: MEDACTA INTERNATIONAL SA MUST MINI POLYAXIAL SCREW 3.5 X 20 FULL THREAD + NUT; POLYAXIAL SCREW + NUT

Catalog Number 03.75.005

Device Problem Device Issue (2379)

Patient Problem Failure of Implant (1924)

Event Date 01/05/2018

Event Type  malfunction  

Manufacturer Narrative

Batch review performed on 31 january 2018.Lot 1720776: 50 items manufactured and released on 28 september 2017.Expiration date: 2022-09-12 no anomalies found related to the problem.To date, 10 items of the same lot have been already sold without any similar reported event.Must mini polyaxial screw 3.5 x 16 full thread + nut reference 03.75.003 (k171369) (5 items involved all on lot 1720774) lot 1720774: 77 items manufactured and released on 04 october 2017.Expiration date: 2022-09-11 no anomalies found related to the problem.To date, 29 items of the same lot have been already sold without any similar reported event (5 items of this lot involved in this complaint).On 01 february 2018 r&d director reported: i have discussed the events with surgeon.We were able to replicate the failure of the reduction device reported after three attempts.He had to apply relay a lot of force in order to create the interface between the tulip and the reduction device to fail.This is very uncommon in the cervical spine.Concerning the cross-threading reported the problem is most likely caused by a too weak set screw thread start.He strongly press the set screw against the tulip before the start to turn the driver.By doing this he slightly can deform the thread start which cause the cross threading.On 02 february 2018 r&d product manager reported: based on the available information in the complaint, the set screw damage can occurs due to a free hand technique where it is most likely to have such an issue due to wrong alignment of the set-screw at the start.Additionally, limit condition of force exerted on small implant component in such a free hand technique can lead to early failure at the interface.Several instruments are provided in the set to ensure the correct alignment and engagement of the set-screw at the start positioning.Instruments were tested in combination with implants.Internal tests have been performed to reproduce the set-screw cross threading at the start position, and to give evidence of failure mode when set-screw is wrong positioned.

Event Description

The c2-c7 posterior cervical fusion.Lateral mass and pedicle screws had been placed bilaterally.Rod placed bilaterally.Physician had difficulty inserting set screws into tulip heads of screws.Surgeon attempted to use rod reduction device, rod pusher , and counter-torque four arms to attempt to seat rods and engage set caps in tulip head.Six must-c setscrews had to be wasted in efforts to seat screws and finally tighten.Physician stated that tulip heads splayed and set screws were cross-threaded.This added an additional hour to the patient's procedure and the physician stated he was unable to achieve the desired degree of cervical lordosis due to the inability to reduce off of the tulip head of the screws.

• Brand Name: MUST MINI POLYAXIAL SCREW 3.5 X 20 FULL THREAD + NUT
• Type of Device: POLYAXIAL SCREW + NUT
• Manufacturer (Section D): MEDACTA INTERNATIONAL SA; strada regina; castel san pietro, 6874 ; SZ 6874
• Manufacturer (Section G): MEDACTA INTERNATIONAL SA; strada regina; castel san pietro, 6874 ; SZ 6874
• Manufacturer Contact: stefano baj ; strada regina; castel san pietro, 6874 ; SZ 6874
• MDR Report Key: 7237222
• MDR Text Key: 99780993
• Report Number: 3005180920-2018-00019
• Device Sequence Number: 1
• Product Code: KWP
• UDI-Device Identifier: 07630030863196
• UDI-Public: 07630030863196
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: K171369
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative
• Reporter Occupation: Other
• Type of Report: Initial
• Report Date: 02/02/2018

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 02/02/2018
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Expiration Date: 09/12/2022
• Device Catalogue Number: 03.75.005
• Device Lot Number: 1720776
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: No
• Was the Report Sent to FDA?: No
• Date Manufacturer Received: 01/05/2018
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 09/28/2017
• Is the Device Single Use?: Yes
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Initial
• Patient Sequence Number: 1
• Patient Outcome(s): Other