MAUDE Adverse Event Report: AESCULAP AG S4 ELEMENT MIS POLYAXIAL SCREW 6.5X50MM; SPINE SURGERY

Model Number ST065T

Device Problem Fracture (1260)

Patient Problems Failure of Implant (1924); Implant Pain (4561)

Event Date 07/11/2023

Event Type  Injury  

Event Description

It was reported that there was an issue with the product st065t - s4 element mis polyaxial screw 6.5x50mm.According to the complaint description, postoperatively, the patient complained of pain and an x-ray was ordered.The results showed disassembly of the screw head from the body, which had been implanted in the l4 segment of vertebrae.During the revision on (b)(6) 2023, the screw was removed and replaced.It was noted that the screw head was missing a third element, and the rest of the device was undamaged.A revision was required.According to manufacturer's reporting evaluation in accordance with 21 cfr 803, section 803.3, this event is considered reportable for the following reason: - serious injury (report not later than 30 days).The assessment for the reportability of this adverse event was based on patient harm, revison surgery.Further information was not provided.The adverse event is filed under aesculap ag reference no.(b)(4).

Manufacturer Narrative

Manufacturing site evaluation: investigation on-going.Additional information / investigation results will be provided in a supplemental report.

Event Description

Update: involved component: sw790t/ s4 set screw new version - lot 52682204 (internal aesculap ag ref.No.(b)(4)).

Manufacturer Narrative

Additional information: b5 - update.D10- involved component.H3 - evaluation, yes.H6 - codes updated.Investigation results: the implant was received in a disassembled state.A visual inspection was performed.The insert of the pedicle screw is missing.In the next step the bottom of the body of the complained screw was investigated.Here was found some deformations at the rim.A measurement of the diameter and subsequent comparison with the specifications in the design drawing showed that the opening at the bottom of the body was widened.The diameter is stated in the drawing as 6,731 -0,025 mm, the measurement on this part resulted in 7,03 mm and is therefore outside the specification.After that the screw was investigated.The threaded body is in a proper condition and shows no damages or deformations.The ball- head of the screw shows heavy signs of abrasion.The diameter was measured of the ball head at the high abrasion areas and compared the result with the specifications in the design drawing.The result of the measurement was 6,94 mm, the specification of the drawing is 7,112 -0 ,025 mm, the measured dimension is therefore outside the specification.Another pedicle screw was prepared by removing the insert and then a rod was inserted, which was properly fixed with a set screw.The fixation of the rod in the body of a pedicle screw was successful even when the insert is missing.But it was noted that there is a possibility of an up- down motion of the threated body and its ball- head in the body.At last the set screw was investigated (involved component).At its bottom was found the typically sickle shaped deformation which is a sure hint that the rod was placed correctly in the head of the pedicle screw and the correctly tightening of the set screw.The thread of the set screw shows no signs of deformation or damages which could be hints for a handling error like cross threading.Batch history review: the device quality and manufacturing history records have been checked for all leading device(s) lot numbers and the products found to be according to our specification valid at the time of production.Currently there are no further complaints with this lot and error pattern at hand.According to manufacturer's reporting evaluation in accordance with 21 cfr 803, section 803.3, this event is considered reportable for the following reason: - serious injury (report not later than 30 days).The assessment for the reportability of this adverse event was based on patient harm, revison surgery.Conclusion/preventive measures: the primary cause of the damage found on the screw examined is the fact that it was implanted with a missing insert.This can be determined with certainty based on the damage pattern and by recreating the situation with a specially prepared screw.As could be seen from the impressions on the bottom and the thread of the set screw, the further course of the implantation was flawless.When the rod is fixed, the insert in the body of the screw presses onto the ball head of the screw body and thus prevents any further movement between the ball head and the body/fixation construct.Without the insert this fixation is not given.A clear root cause why the pedicle screw lost its insert cannot be drawn.Since the insert is checked several times during the production of the screw, it can be ruled out that the pedicle screw was delivered without an insert.Neither the quality records of the screw nor the insert showed any peculiarities or deviations that would indicate an expected problem such as the present one.Based upon the investigation results, a capa is not required.

• Brand Name: S4 ELEMENT MIS POLYAXIAL SCREW 6.5X50MM
• Type of Device: SPINE SURGERY
• Manufacturer (Section D): AESCULAP AG; po box 40; tuttlingen, 78501 ; GM 78501
• Manufacturer (Section G): AESCULAP AG; po box 40; tuttlingen, 78501 ; GM 78501
• Manufacturer Contact: christian von der grün ; po box 40; tuttlingen, 78501 ; GM 78501
• MDR Report Key: 18576508
• MDR Text Key: 333659210
• Report Number: 9610612-2024-00006
• Device Sequence Number: 1
• Product Code: NKB
• Combination Product (y/n): N
• Reporter Country Code: MX
• PMA/PMN Number: K090657
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Foreign,Company Representative
• Reporter Occupation: Other Health Care Professional
• Type of Report: Initial,Followup
• Report Date: 02/23/2024

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 01/24/2024
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Model Number: ST065T
• Device Catalogue Number: ST065T
• Device Lot Number: 52679419
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 09/05/2023
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 01/30/2023
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 03/25/2021
• 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
• Treatment: SW790T - LOT 52682204
• Patient Outcome(s): Required Intervention
• Patient Age: 33 YR
• Patient Sex: Male