MAUDE Adverse Event Report: AESCULAP AG METHA NECK 12/14 135°/0°; HIP ENDOPROSTHETICS

Model Number NC088K

Device Problem Biocompatibility (2886)

Patient Problems Failure of Implant (1924); Metal Related Pathology (4530)

Event Date 07/26/2021

Event Type  Injury  

Manufacturer Narrative

Manufacturing site evaluation: investigation on-going.Should relevant additional information / investigation results become available, a supplemental medwatch report will be submitted.

Event Description

It was reported to aesculap ag that a metha® short hip system (part # nc088k) was implanted during a procedure performed approximately 13 years and 4 months ago.According to the complainant, the patient experienced a large osteolysis of the left pelvis with stable cup.The patient underwent a revision procedure on (b)(6) 2021.The modular methashaft was discoloured black at the cone connection.The complaint device was returned to the manufacturer for evaluation.Although requested, additional information has not been made available.The adverse event is filed under (b)(4) reference xc (b)(4).Involved components : nc085t - metha short hip stem cap size 5 - lot 51414643.Nk560 - biolox prosthesis head 12/14 32mm s - lot unknown.

Manufacturer Narrative

Investigation results: visual investigation: investigation was carried out visually and microscopically.The explanted cone adapter nc088k shows visible dark coloration which could be metal abrasion/corrosion and/or material of organic origin.In order to demonstrate the wear patterns on the cone surface, a macroscopical investigation of the cone was performed.The cone surface shows clearly visible wear patterns in the medial and lateral contact areas due to dynamic stress after more than 13 years in vivo.Due to the introduction of force and biomechanical load vector, the medial and lateral cone sides represent the main contact surfaces.On the medial cone surface, the damage is concentrated on a liner contract area through which the high bending moments is introduced into the prosthesis stem.The macroscopical investigation of the metha neck shows that due to dynamic corrosive stress the cone surface exhibits wear patterns.Based on our experience from former similar cases, we assume that the cone surface was damaged as a consequence of a combination of fretting and corrosive effects.The limited repassivation of the surface and the characteristic wear patterns indicate that due to metal dissolution on aggressive surrounding conditions the mechanical abrasion was massively strengthened.It is possible that a wear induced reaction associated with a patient related higher sensitivity and an aggressive environmental condition led to the corrosion of the metha neck.Batch history review: the device quality and manufacturing history records have been checked for the available lot number and were found to be according to our specifications valid at the time of production.Review of the complaint history revealed that no similar complaints have been filed against products from this batch number.The review of risk assessment revealed that the overall risk level (severity 7 (10) x probability of occurrence 2(10)) according to din en iso 14971 is still acceptable.Conclusion and measures / preventive measures: based upon the investigation results a clear root cause conclusion cannot be drawn.There is no indication for a material-, manufacturing- or design-related failure.Based upon the investigations results a capa is not necessary.

• Brand Name: METHA NECK 12/14 135°/0°
• Type of Device: HIP ENDOPROSTHETICS
• 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: 12343276
• MDR Text Key: 267297186
• Report Number: 9610612-2021-00578
• Device Sequence Number: 1
• Product Code: LWJ
• UDI-Device Identifier: 04046963183745
• UDI-Public: 4046963183745
• Combination Product (y/n): N
• Reporter Country Code: GM
• PMA/PMN Number: K071916
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Other,Foreign,Health Professional,Company Representative
• Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date: 01/20/2022

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Expiration Date: 01/30/2018
• Device Model Number: NC088K
• Device Catalogue Number: NC088K
• Device Lot Number: 51457615
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 08/03/2021
• Is the Reporter a Health Professional?: Yes
• Initial Date Manufacturer Received: 07/30/2021
• Initial Date FDA Received: 08/19/2021
• Supplement Dates Manufacturer Received: 12/22/2021
• Supplement Dates FDA Received: 01/20/2022
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 12/06/2007
• Is the Device Single Use?: Yes
• Is This a Reprocessed and Reused Single-Use Device?: No
• Type of Device Usage: Unknown
• Patient Sequence Number: 1
• Treatment: NC085T - LOT 51414643; NK560 - LOT UNKNOWN; NC085T - LOT 51414643; NK560 - LOT UNKNOWN
• Patient Outcome(s): Required Intervention
• Patient Age: 77 YR
• Patient Sex: Female