MAUDE Adverse Event Report: MEDACTA INTERNATIONAL SA GMK-HINGE FIXED TIBIAL INSERT SIZE 2/20MM

Catalog Number 02.09.0220H

Device Problem Break (1069)

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

Event Date 03/24/2017

Event Type  malfunction  

Manufacturer Narrative

Batch review performed on 19 april 2017.Lot 143011: (b)(4) items manufactured and released on 11 july 2014.Expiration date: 2019-05-31.No anomalies found related to the problem.To date, (b)(4) items of the same lot have been already sold without any similar reported event.Additional information received on 20 april 2017 and includes: the revision is scheduled for (b)(6) 2017, the screw will be available at this date.Not yet explanted.

Event Description

The patient came in with knee embarrassment.X-ray shows breakage of the locking inlay screw.The surgeon planned to review this patient on (b)(6) 2017.

Manufacturer Narrative

The medical affairs director performed a clinical evaluation based on the available x-ray and commented as follows: insert fixation screw is found broken two years after revision tkp.The only x-ray available shows the broken screw at two years; it is not possible to assess screw status after the first operation.No details were supplied as to the use of a torque-limiting screwdriver during the implant and no details describing events during surgery are available.Therefore, no conclusion from the clinical investigation can be drawn at this stage.Additional information received on 16 may 2017 and includes: the revision surgery was completed successfully on (b)(6) 2017.Additional information received on 19 may 2017 and includes: the intra-operative result is satisfactory.It was confirmed that the revision surgery was due to the broken screw.Not yet received.

Manufacturer Narrative

On (b)(4) 2017 the r&d project manager performed a visual inspection of the retrieved explanted components and commented as follows: tibia implant composed by: tibia baseplate - available for visual inspection.Double 5mm tibia augments - available for inspection still screwed to tibia baseplate.3mm offset connector - available for inspection still assembled to tibia baseplate.Cementless stem d11 l65 - available for inspection still assembled to offset connector.Hinge post extension - available for inspection.Hinge post screw - available for inspection.Uhmwpe insert - not available for inspection.Tibia insert fixation screw - available for inspection.The screw is found broken in 2 pieces.It is broken in the threaded shaft, in correspondence to the section at the level of the tibia baseplate.The remaining part of the screw is inside the tibia baseplate.Femoral implant composed by: hinge femoral component - available for inspection.Cementless stem - available for inspection still assembled to femoral component.The uhmwpe external bush for hinge post is found plastically deformed in the part that comes in contact with the hinge post.Due to this deformation the mechanical lock to limit hyperextension pass from 3 degrees to about 9 degrees.Conclusion: in a similar event occurred in the past, the screw was sent to an external laboratory for a failure analysis.The result of this analysis could most likely be applied also at this event.As a conclusion, the screw broke failed due to fatigue.The fracture morphology indicates that reversed bending took place, the bending however occurred primarily in one direction.A single and distinct fracture origin could not be found.Instead, a multitude of nonspecific fracture origins are observed along the thread root.The area of fracture origin does not show any distinctive features, apart from the fact that the material is slightly deformed at the bottom of the thread root.The thread root appears to have acted as a stress concentrating notch, since cracks are visible in several more positions.Judging from the results, the material itself does not seem to have been a contributing factor to the failure, as it shows ductile behaviour and the microstructure is fine-grained and homogeneous.Fatigue failure after 2 years from the implantation is an unlikely event.Since the material itself doesn't seem to have been a contributing factor to failure, we can only suppose that an excessive, unpredictable and unexpected stresses have been applied on the screw during tightening (caused by the misalignment of the screwdriver during fixation) or during activities of daily living.The most likely cause for this excessive load applied, could be related to the instability and the misalignment of the joint after the primary hinge surgery.Several elements lead us suppose that the joint was not stable and well positioned during primary surgery: a thicker tibia insert was used during revision surgery (during revision it was chosen to pass from a 20mm insert to a 23mm insert).An upsizing of the femur was required passing from a size 2 to a size 3 in revision adding 2 distal augments and 2 posterior augments to distalize the joint line and posteriorize the joint line in flexion.A correction tibia cut to better aligned the component was performed during revision surgery.Laxity of the collateral ligaments, as confirmed by the sales rep.Mal-positioning of the implant, instability and laxity could have lead to unexpected flexion - extension movement.In particular, the implants seems to have worked often in excessive hyperextension configuration with consequent excessive and unpredictable load transmission to the implant and in particular between the hinge post extension and the insert.Those loads could have caused the breakage of the fixation screw.These considerations lead us state that the event is not implant related.

• Brand Name: GMK-HINGE FIXED TIBIAL INSERT SIZE 2/20MM
• Type of Device: FIXED TIBIAL INSERT
• Manufacturer (Section D): MEDACTA INTERNATIONAL SA; strada regina; castel san pietro, 6874 ; SZ 6874
• Manufacturer (Section G): MEDACTA INTERNATIONAL SA; strada regina; castel san pietro, 6874 ; SZ 6874
• Manufacturer Contact: stefano baj ; strada regina; castel san pietro, 6874 ; SZ 6874
• MDR Report Key: 6511308
• MDR Text Key: 73374774
• Report Number: 3005180920-2017-00198
• Device Sequence Number: 1
• Product Code: KRO
• Combination Product (y/n): N
• Reporter Country Code: FR
• PMA/PMN Number: K130299
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: company representative
• Reporter Occupation: Other
• Type of Report: Initial,Followup,Followup
• Report Date: 07/21/2017

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 04/21/2017
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Expiration Date: 05/31/2019
• Device Catalogue Number: 02.09.0220H
• Device Lot Number: 143011
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 06/21/2017
• Is the Reporter a Health Professional?: No
• Was the Report Sent to FDA?: No
• Date Manufacturer Received: 03/24/2017
• Was Device Evaluated by Manufacturer?: Yes
• Date Device Manufactured: 07/11/2014
• 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: 59 YR