MAUDE Adverse Event Report: SYNTHES HAGENDORF STARDRIVE SCREWDRIVER SHAFT T8SELF-RETAINING/QC; APPLIANCE,FIXATION,SPINAL INTERVERTEBRAL BODY

Catalog Number 03.617.902

Device Problem Fitting Problem (2183)

Patient Problem No Known Impact Or Consequence To Patient (2692)

Event Date 10/06/2016

Event Type  malfunction  

Manufacturer Narrative

This device was used for treatment, not diagnosis.Device is an instrument and is not implanted/explanted.The investigation could not be completed; no conclusion could be drawn, as no product was received.No ncrs were generated during production.Review of the device history record(s) showed that there were no issues during the manufacture of the product that would contribute to this complaint condition.If information is obtained that was not available for the initial medwatch, a follow-up medwatch will be filed as appropriate.

Event Description

It was reported that while performing an anterior cervical discectomy and fusion (acdf) procedure on (b)(6) 2016, using zero-p, the t8 stardrive shaft was not holding onto the screws appropriately and some screws were stripping.As the surgeon was attempting to insert the screws in the zero-p implant in the c4-5 space, six (6) of the screws were stripping instead of tightening and locking into the surface plate.Two (2) of the six (6) screws disengaged from the driver; bone wax was used to adhere the screws onto the driver.It was believed that this was a result of the t8 stardrive shaft not holding onto the screw as rigidly as it should have and therefore the screw followed its own path and trajectory.The t8 stardrive shaft was swapped out and all six (6) stripped screws were discarded.There was another shaft and other screws readily available for use to complete the procedure successfully.There was a two (2) minute surgical delay to remove the malfunctioned screws and open new packs of screws for use.It was reported that the patient's status outcome is unknown.Concomitant devices reported: 8mm zero-p cages (part # 04.617.128s, lot # l049297, l049298, l060362, quantity 3).This report is 1 of 7 for (b)(4).

Manufacturer Narrative

The device was received, the investigation could not be completed, and no conclusion could be drawn, as product is entering the complaint system.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.

Event Description

When the device was returned to the manufacturer it was noted that the returned stardrive screwdriver shaft has a broken tip, with fragments missing.

Manufacturer Narrative

Device was used for treatment, not diagnosis.Additional narrative: a product development investigation was performed for the subject device.Only the screwdriver shaft was returned for evaluation at customer quality (cq).The returned screwdriver shaft was examined upon receipt and the complaint condition of not fitting with other parts was able to be confirmed.The stardrive distal edges are worn and rounded which could contribute to it not mating properly with the drive recess in related screws.The length of the returned screwdriver shaft measures 142.1mm at customer quality (cq) which is within specification of 140.8mm - 143.2mm per relevant product drawing.No definitive root cause was able to be determined however the failure mode is typically associated with rough handling and/or the application of excessive force during screw insertion the complaint condition could not be replicated at cq because only the screwdriver shaft and not the screws were returned for evaluation.The stardrive screwdriver shaft t8, self-retaining/qc, (03.617.902) is one of four t8 screw insertion drivers in both the zero-p and zero-p variable angle (va) systems.The zero-p system notes that a 1.2 nm torque limiting attachment (03.110.002.99) must be used for screw insertion, cautioning: ¿if the torque limiting attachment is not used, breakage of the driver may occur, potentially increasing risk to the patient¿.When inserting screws in the va system, no torque limiting attachment is necessary as the screw head is retained by a blocking mechanism once fully inserted.For removal it is noted that a torque limiting attachment should not be used.The screwdriver shaft t8 (03.617.902) was evaluated in a static torsional test resulting in the following conclusion: ¿the screwdriver shafts remain in the elastic range up to a torque of between 2nm and 2.2nm.The maximum of the plastic range and hence the maximum torque is achieved on the average after 2.49nm.Then the tip shears off.The tips achieve different maximum rotation angles until rupture occurs.¿ through the testing two of four tips deformed, another sheared partially and the final sheared completely.As according to the aforementioned test, deformation occurs between 2-2.2nm and failure occurs at approximately 2.49nm, it is determined that the returned instrument was exposed to values outside of the intended operating range causing the tip to deform/wear.Relevant drawings for the returned instrument were reviewed.The design, materials and finishing processes were found to be appropriate for the intended use of these devices.During the investigation no product design issues or discrepancies were observed that may have contributed to the complaint condition.If information is obtained that was not available for the initial medwatch, a follow-up medwatch will be filed as appropriate.

• Brand Name: STARDRIVE SCREWDRIVER SHAFT T8SELF-RETAINING/QC
• Type of Device: APPLIANCE,FIXATION,SPINAL INTERVERTEBRAL BODY
• Manufacturer (Section D): SYNTHES HAGENDORF; im bifang 6; hagendorf CH461 4; SZ CH4614
• Manufacturer (Section G): SYNTHES HAGENDORF; im bifang 6; hagendorf CH461 4; SZ CH4614
• Manufacturer Contact: mark vornheder ; 1302 wrights lane east; west chester, PA 19380 ; 6107195000
• MDR Report Key: 6055318
• MDR Text Key: 58362125
• Report Number: 3003875359-2016-10555
• Device Sequence Number: 1
• Product Code: KWQ
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: K152239
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative,health
• Reporter Occupation: Other
• Type of Report: Initial,Followup,Followup
• Report Date: 10/06/2016

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 10/25/2016
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Catalogue Number: 03.617.902
• Device Lot Number: 8088852
• Other Device ID Number: (01)10705034717166(10)8088852
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 11/03/2016
• Is the Reporter a Health Professional?: No
• Date Manufacturer Received: 12/05/2016
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 09/28/2012
• Is the Device Single Use?: No
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Unknown
• Patient Sequence Number: 1
• Treatment: 8MM ZERO-P CAGES (PART # 04.617.128S, LOT # L04929