MAUDE Adverse Event Report: AESCULAP AG ENDURO FEMORAL COMPONENT CEMENTED F2L; KNEE ENDOPROSTHESES

Model Number NB015K

Device Problem Patient Device Interaction Problem (4001)

Patient Problems Foreign Body In Patient (2687); Patient Problem/Medical Problem (2688)

Event Date 06/13/2019

Event Type  Injury  

Manufacturer Narrative

Height: 162cm.Investigation: the components have been examined visually and microscopically.The external screw thread of the rotation axis show visible damages/material abrasions on the whole circumference.Furthermore the taper of the rotation axis shows visible damages.The distal end of the inner thread of the rotation axis locknut shows damages.There are little metal inclusions on the gliding surface of the meniscal component.Batch history review: the device quality and manufacturing history records have been checked for all available lot number and found to be according to specification valid during the time of production.No similar incidents have been filed with products from these batches.Conclusion and root cause: based on the information available as well as a result of our investigation the root cause of the failure is not product related.We assume that the failure is probably usage/patient related.Rationale: there are no hints for a material problem.According to the quality standard and dhr files a material defect and production error is improbable.One reason for loosening the rotation axis locknut postoperatively could be: when the connection between the axis taper and the femur could not firmly fitted, there is a gap and hence movement between the components.This leads to the femur safety nut unscrewing or to the axis breaking above the taper.The taper must be firmly pressed together and the femur safety nut assembled and pre-tightened using the instrument np420r.Then the counter-holder np419r together with the instrument np420r is used to tighten the taper with 20nm using the torque wrench n184m.The femur safety nut is then screwed on using holder np455r by hand.The counter-holder is then attached to the femur and the femur safety nut is then tightened with 20nm using the torque wench.When these steps are carried out accurately it should not be possible for the construct to come apart in situ.The visual examination shows typical damage to both the taper and the thread.The damage of the taper is an indication that the hinge connection of the femur has been moving on the taper.The position of the thread damage at the distal end of the femur safety nut indicates that the nut was not fully engaged on the thread of the axis.A further point to mention is the patient's height and weight, which also might contribute to the loose joining of the prosthetic components.No capa necessary.

Event Description

It was reported the locking nut loosened post-operatively.The patient was now presented with high instability (no event, no fall).An x-ray was performed and the patient was scheduled for revision surgery.During the revision surgery, it was found that the lock nut (nr860) had come loose.It was also found that the joining of the meniscal component nr880 had also come loose.A new nr881 insert with nr860 was implanted without any problems.Concomitant: nr880, enduro meniscal component f2 10mm 51737924; nr792k, enduro replacem.Tibia ring f/nr872/nr880 51776289; nb012k, enduro tibial comp.Offset cemented t2 unknown; nr291k, femur extens.Stem 6° d12x77mm cemented unknown; nr192k, tibia offset stem d15x52mm cemented unknown; nr377k, enduro femur spacer post/dist f2 4x8mm unknown; nb056k, enduro tibia hemi-wedge t2 8mm rl/lm unknown; nr400k, nut f/femur extens.Stem all sizes neutr.Unknown.

• Brand Name: ENDURO FEMORAL COMPONENT CEMENTED F2L
• Type of Device: KNEE ENDOPROSTHESES
• 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: kerstin rothweiler ; am aesculap-platz; tuttlingen, baden-wurttemberg 78501 ; GM 78501
• MDR Report Key: 8780064
• MDR Text Key: 150682363
• Report Number: 9610612-2019-00452
• Device Sequence Number: 1
• Product Code: KRO
• Combination Product (y/n): N
• Reporter Country Code: GM
• PMA/PMN Number: K101815
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative,foreig
• Reporter Occupation: Other Health Care Professional
• Type of Report: Initial
• Report Date: 07/10/2019

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 07/11/2019
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Expiration Date: 04/01/2016
• Device Model Number: NB015K
• Device Catalogue Number: NB015K
• Device Lot Number: 51756771
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 06/25/2019
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 06/13/2019
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 04/01/2016
• 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): Required Intervention
• Patient Age: 70 YR
• Patient Weight: 106