MAUDE Adverse Event Report: AESCULAP AG ENDURO MENISCAL COMPONENT F2 14MM; KNEE ENDOPROSTHESIS

Model Number NR882

Device Problem Fracture (1260)

Patient Problems Thrombosis (2100); Joint Disorder (2373)

Event Date 12/10/2018

Event Type  Injury  

Manufacturer Narrative

(b)(4).Patient date of birth: month and day are unknown; year of birth is (b)(4).Preliminary investigation: the products were returned for investigation in a contaminated state; at the time of this report, they are being decontaminated and have not undergone a complete investigation.Additional information/ investigation results will be provided in a supplemental report.Pictures of the product were also provided.Review of the pictures indicates that the axis has fractured above the taper, directly below the screw thread.The device quality and manufacturing history records have checked for all available lot numbers and were found to be according to specification valid at the time of production.No similar incidents have been filed against these lot numbers.Based on the information currently available, a root cause cannot be determined.It is possible that the fracture occurred due to a patient related mechanical overload situation.Additionally, if the connection between the axis taper and the femur component is not firmly fitted there is a gap and hence movement between the components; this can lead to a possibility that the axis can fracture above the taper, as a result of mechanical overload.

Event Description

It was reported that postoperatively the connecting axis broke between the tibial and femoral portions of the total knee prosthesis.The patient's first knee implantation date and details were not provided; the left knee had been implanted and then required replacement due to severe ligamentary instability.The replacement surgery occurred on (b)(6) 2011 (see concomitant implants listed below), during which the enduro meniscal component f2 was also implanted.For about 1 year after the procedure, the patient heard "cracking noises" in the joint.Over 7 years after the replacement, the patient experienced a thrombosis and was admitted to the hospital.The cause was believed to be due to subluxation in the left knee; the enduro axis piece was then found to be broken and a revision was planned.The explant of the central axis and revision was performed on (b)(6) 2018, and the axis was successfully replaced.Additional information has been requested.This report addresses the axis/enduro meniscal component.Involved components reported as concomitant devices: nr195k/tibia offset stem d15x92mm cemented/batch 51684459; nb055k /enduro tibia hemi-wedge t2 4mm rl/lm/batch 51732475; nb045k/enduro tibia hemi-wedge t2 4mm rm/ll/batch 51737623; nr400k/nut f/femur extens.Stem all sizes neutr./batch 51752640; nr794k/enduro repl.Tib.Ring f/nr874/nr882/nr891/batch 51776264; nr292k/femur extens.Stem 6° d15x77mm cemented/batch 51725835.Associated medwatches: 9610612-2019-00016, 9610612-2019-00017.

Manufacturer Narrative

Associated reports: 9610612-2019-00016, 9610612-2019-00017.Investigation: the components were examined visually and microscopically with a keyence vhx-5000 digital microscope and a panasonic dmc tz8 digital camera.Furthermore this case was discussed with specialists from the marketing and development department.It was found that the rotation axis has fractured above the taper, directly below the screw thread.The brakage surface of the larger distal part of the axis as well as the proximal fragment show secondary damages, therefore it is not possible to analyze the breakage surface regarding fracture type.We assume that the rotation axis locknut has been loosened from the screw thread of the rotation axis before the breakage.This rotation axis locknut is fixed on the underside of the meniscal component.The visible underside of the rotation axis locknut shows material abrasion, probably from the contact with the tibial component.The meniscal component is in a damaged condition.The device is divided into two parts.Furthermore there are visible delaminations and enormous deformations.Additionally we found fixed metal chips on the gliding surface of the meniscal component.The locking ring and the bearing for rotation axis show no unusual damages.Furthermore it should be mentioned that one of the provided pictures clearly shows signs of hyperextension (a notch on the hinge ring of the femur component).The x-ray figures showed the decoupled implant and subluxated position of the left knee before the revision operation.Batch history review: the divice quality an manufacturing history records have been checked for all available lot numbers and found to be according to our specification valid at 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 most probably usage related.Rationale: according to the quality standard and dhr files, a material defect or production error can be excluded.Furthermore there are no hints of a material or manufacturing problem.When the connection between the taper of the rotation axis and the femur component could not be firmly fitted, there is a gap, and hence movement between the components.This leads to the rotation axis locknut unscrewing or the rotation axis breaking above the taper.The load transfer in this case is transmitted through the narrowest part of the axis and not through the main axis.The cause for this failure type is usage related.No capa is necessary.

• Brand Name: ENDURO MENISCAL COMPONENT F2 14MM
• Type of Device: KNEE ENDOPROSTHESIS
• Manufacturer (Section D): AESCULAP AG; po box 40; tuttlingen, 78501 ; GM 78501
• MDR Report Key: 8227960
• MDR Text Key: 132496365
• Report Number: 9610612-2019-00001
• Device Sequence Number: 1
• Product Code: KRO
• Combination Product (y/n): N
• PMA/PMN Number: K101815
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: foreign,health professional
• Type of Report: Initial,Followup
• Report Date: 01/15/2019

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 01/08/2019
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Expiration Date: 12/01/2015
• Device Model Number: NR882
• Device Catalogue Number: NR882
• Device Lot Number: 51725915
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 12/20/2018
• Distributor Facility Aware Date: 01/11/2019
• Date Manufacturer Received: 01/11/2019
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Treatment: FEMUR EXTENSION; FEMUR EXTENSION NUT; TIBIA HEMI WEDGE RL/LM; TIBIA HEMI WEDGE RM/LL; TIBIA STEM; TIBIAL RING
• Patient Outcome(s): Required Intervention
• Patient Age: 76 YR