MAUDE Adverse Event Report: STRYKER GMBH UNKNOWN STAR MOBILE BEARING; PROSTHESIS, ANKLE, UNCEMENTED, NON-CONSTRAINED

Catalog Number UNK_SEL

Device Problem Loss of or Failure to Bond (1068)

Patient Problems Pain (1994); Swelling (2091)

Event Date 03/05/2018

Event Type  Injury  

Manufacturer Narrative

Once the investigation has been completed any additional information will be reported in a supplemental report.

Event Description

Patient presented with pain and swelling.It was decided a fusion was necessary.

Manufacturer Narrative

The reported event that an unknown star mobile bearing was alleged of 'fusion' could not be confirmed, since the device was not returned for evaluation and no other evidences were provided.In the case presented a female patient had been treated with star in 2011.On march, 2018 the patient had to be revised as she was having pain and swelling in the ankle.The total ankle replacement was removed and replaced by tibia/talar/calcaneus fusion.The pe shows small signs of wear, such that it is trimmed on one of its lateral sides, and worn near the sliding groove.This was likely produced by the articulation with the talar component.The tibial- as well as the talar components showed signs of use in the form of scratches, but no significant damage.Overall the results of the stage 1 analysis are consistent with well-positioned and well-functioning devices implanted for approximately 7 years.Pain is a known complication, is listed in the ifu as a known adverse effect and had been clinically assessed by a consultant hcp: ¿prior to surgery, star ankle patients had a higher level of pain than did arthrodesis patients.At all follow-up evaluations, pain levels in both groups dropped.There was a larger improvement in mean star ankle patient pain vas scores over the course of the study when compared to arthrodesis patients (51.8 (n = 144 star patients) versus 44.6 (n = 45 control patients) at 24 months).¿ since no x-rays post-implantation were provided, it could not be determined whether the implants had been placed according to the anatomical requirements.It could furthermore not be determined if the components had been implanted in the correct positions.Regarding the outstanding patient data (e.G weight, height, pre-existing illnesses, unreasonable stresses) it could not be determined if the patient conditions were adequate for the used implant respectively if potential adverse effects may have contributed to the pain experienced.Nevertheless, it is important to precise that the implant has a limited service life, and should not be expected to withstand mechanical loads such as a healthy bone.Normal wear of the device is thus predictable.As a reminder, the ifu states: ¿ improper selection, placement and fixation of the implant components may result in early implant failure.As in the case of all prosthetic implants, the durability of these components is affected by numerous biologic, biomechanic and other extrinsic factors which limit their service life.Accordingly, strict adherence to the indications, contraindications, precautions and warnings for this product is essential to potentially maximize service life.¿ and ¿ 5 patient education warn the patient of the surgical risks, possible adverse effects and possible operative complications that may occur with joint arthroplasty.Warn the patient of the limitations of artificial joint replacement devices.Caution the patient to protect the joint replacement from unreasonable stresses and to follow the treating physician¿s instructions.In particular, warn the patient to strictly avoid high impact activities such as running and jumping.Warn the patient that artificial joint replacement devices can wear out over time, and may require replacement.Reported device related adverse effects the most commonly reported adverse effects associated with the star ankle are the following: bone fracture (talus, tibia) pain and nerve injury¿.A review of the device history for the reported lot did not indicate any abnormalities.No corrective actions are required at this time.A review of the labeling did not indicate any abnormalities.No indications of material, manufacturing or design related problems were found during the investigation.If any further information is provided, the investigation report will be updated.

Event Description

Patient presented with pain and swelling.It was decided a fusion was necessary.

Event Description

Patient presented with pain and swelling.It was decided a fusion was necessary.

Manufacturer Narrative

The reported event was not returned for evaluation and no other evidence was provided.In the case presented a female patient had been treated with star in 2011.On (b)(6) 2018 the patient had to be revised as she was having pain and swelling in the ankle.The total ankle replacement was removed and replaced by tibia/talar/calcaneus fusion.The pe shows small signs of wear, such that it is trimmed on one of its lateral sides, and worn near the sliding groove.This was likely produced by the articulation with the talar component.The tibial- as well as the talar components showed signs of use in the form of scratches, but no significant damage.Overall the results of the stage 1 analysis are consistent with well-positioned and well-functioning devices implanted for approximately 7 years.Pain is a known complication, is listed in the ifu as a known adverse effect and had been clinically assessed by a consultant hcp: ¿prior to surgery, star ankle patients had a higher level of pain than did arthrodesis patients.At all follow-up evaluations, pain levels in both groups dropped.There was a larger improvement in mean star ankle patient pain vas scores over the course of the study when compared to arthrodesis patients (51.8 (n = 144 star patients) versus 44.6 (n = 45 control patients) at 24 months).¿ since x-rays were provided, a medical statement was requested from a clinical expert.Their statement is as follows: "[.] the presented case shows a now 71 y old female.She was treated surgically with a star ankle joint prosthesis seven years ago.Attached is the protocol for the revision operation the report on the primary operation.X-rays of the ankle joint with the dislocated prosthesis before the operation and photographs of the explanted prosthesis.No x-rays pre- or postoperatively after the insertion of the prosthesis are provided.From the medical discharge letter in 2011 we find that the patient had three problems, unfortunately a personal opinion can not be made because of the missing x-rays of that time: arthrosis of the ankle joint, severe varus deformity, shortening of the gastrocnemius and soleus muscle with consecutive shortening of the achilles tendon.The surgeon mentions that the bone stock allows only for the implant of a very small prosthesis.With this information given a failure of the ankle prosthesis after a relatively short period of seven years is not too surprising.If we look at the x-rays before the explantation we can see a severe varus deformity with dislocation of both of the components tibial and talus.The talus component is considerably dislocated distally.The massive malalignment in the axis led to further stress of the distal fibula and a consecutive fracture at the transition from the middle to the distal third.Together with the information that there was a varus deformity before and that there additionally was a shortening of the achilles tendon, we can assume that even after the implantation of the prosthesis forces once again led to varus deformity and shortening of the dorsal tendomuscular structures.The system collapsed again.This problem is not related to specific design features of the star prosthesis.The question is, whether it was the right decision to implant a prosthesis in the first place.This can not be decided with the given information.[.] " a review of the device history for the reported lot did not indicate any abnormalities.No corrective actions are required at this time.A review of the labeling did not indicate any abnormalities.No indications of material, manufacturing or design related problems were found during the investigation.If any further information is provided, the investigation report will be updated.

• Brand Name: UNKNOWN STAR MOBILE BEARING
• Type of Device: PROSTHESIS, ANKLE, UNCEMENTED, NON-CONSTRAINED
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; CH 2545
• MDR Report Key: 7379610
• MDR Text Key: 103775149
• Report Number: 0008031020-2018-00250
• Device Sequence Number: 1
• Product Code: NTG
• Combination Product (y/n): N
• PMA/PMN Number: P050050
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: health professional
• Type of Report: Initial,Followup,Followup
• Report Date: 11/15/2019

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 03/28/2018
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Lay User/Patient
• Device Catalogue Number: UNK_SEL
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Date Returned to Manufacturer: 03/13/2018
• Date Manufacturer Received: 10/25/2019
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Outcome(s): Required Intervention
• Patient Age: 71 YR