MAUDE Adverse Event Report: STRYKER GMBH SLIDING CORE UHMPWE, 7MM; PROSTHESIS, KNEE, FEMOROTIBIAL, UNICOMPARTMENTAL, SEMI-CONSTRAINED, METAL/POLYME

Catalog Number 400141

Device Problem Device Operates Differently Than Expected (2913)

Patient Problem Pain (1994)

Event Date 04/07/2016

Event Type  Injury  

Manufacturer Narrative

The reported device was manufactured and distributed by small bone innovation, inc., (b)(6) and implanted prior to howmedica osteonics corp.¿s purchase of certain assets of sbi on (b)(6) 2014.Stryker became legal manufacturer of this product on (b)(6) 2015 and has taken the responsibility for medical device reporting.Device will not be returned.If additional information becomes available it will be provided on a supplemental report.Device will not be returned to the manufacturer.

Event Description

As per sales rep voice mail message star sliding core failed.Patient had pain and his talus tipped into varus (right side).Patient had to use cane and cam boot until revision surgery.Dr.Did a debridement, poly swap (sized up to 8mm) and calcaneus osteotomy.

Manufacturer Narrative

Evaluation revealed the sliding core uhmpwe, 7mm to be the subject product.No further associated products were reported.A review of the device history records revealed no discrepancies.Deficiency in material or manufacturing was not found.The affected sliding core was documented as faultless prior to distribution.Thus, we excluded deviations in material and manufacturing.In the case presented a patient had been treated with star on (b)(6) 2013.On (b)(6) 2016, after approximately 3 years of implantation, the patient reported to be having pain.His talus was found to be tipped into varus.The patient was prescribed to canes and cam boot until the revision surgery.The patient was revised on (b)(6) 2016.The polyethylene sliding core was found to be fractured.The attending surgeon did a debridement, removed the broken poly and replaced it with an 8 mm one.A calcaneal osteotomy furthermore had been carried out in order to correct the ankle deformity.Fracture of the polyethylene sliding core in general had been experienced and is nominated in the scientific literature.It does not present an unanticipated event in itself.Depending on the load application, also, depending on the patient¿s post implant behaviour and especially depending on the implant alignment, a polyethylene fracture can rather be classified as anticipated ¿ specifically if one or more contributing issues concurrence with each other.¿like other arthroplasty devices in weight bearing joints such as the hip or knee, it is anticipated that the star ankle will have a finite useful life, at which point the prosthesis will require revision or, in certain cases, removal and fusion.¿ ¿complications due to the meniscal mobile bearing in tars such as luxation, subluxation, massive wear, and fracture of the pe inlay are rare complications.The cause of these complications is regularly not found in the design of this three-piece total ankle replacement.Causes of failure of the mobile bearing are mostly found in incorrect indication, incorrect soft tissue balancing, incorrect positioning of components, implantation in ankles with hind foot malalignment and ankle instability.¿ the returned sliding core was completely fractured in half in the medial/ lateral direction and showed significant material deformation at medial.The polyethylene sliding core featured a talar wear scar (significant abrasive wear and deformation) adjacent to the keel-trough, which was produced by the contact with the talar component articulating with the bearing surface as opposed to the trough.Significant abrasive wear and deformation was furthermore found at the lateral edge, which most likely was linked to bone contact.The above described surface damage of the sliding core was consistent with the reported ankle deformity of the patient.Based on the above information the breakage of the sliding core was not related to a deficiency of the device, but was caused by an eccentric loading of the poly component as the talus of the patient fell into varus.Review of complaint history, capa databases and risk analysis did not identify any discrepancies.There are no open actions in place related to the reported event for the subject product.No non-conformity was identified.In case relevant clinical information should become available, we reserve the right to update the investigation and change the root cause.

Event Description

As per sales rep voice mail message star sliding core failed.Patient had pain and his talus tipped into varus (right side).Patient had to use cane and cam boot until revision surgery.Dr.Did a debridement, poly swap (sized up to 8mm) and calcaneus osteotomy.

• Brand Name: SLIDING CORE UHMPWE, 7MM
• Type of Device: PROSTHESIS, KNEE, FEMOROTIBIAL, UNICOMPARTMENTAL, SEMI-CONSTRAINED, METAL/POLYME
• Manufacturer (Section D): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; CH 2545
• Manufacturer (Section G): STRYKER GMBH; bohnackerweg 1; postfach; selzach 2545 ; CH 2545
• Manufacturer Contact: rose haas ; 325 corporate drive; mahwah, NJ 07430 ; 2018315000
• MDR Report Key: 5624696
• MDR Text Key: 44285566
• Report Number: 0008031020-2016-00225
• Device Sequence Number: 1
• Product Code: NTG
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: P050050
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: health professional
• Reporter Occupation: Physician
• Type of Report: Initial,Followup
• Report Date: 04/07/2016

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 05/03/2016
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Lay User/Patient
• Device Expiration Date: 12/31/2016
• Device Catalogue Number: 400141
• Device Lot Number: 1002122
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 07/06/2016
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 12/01/2011
• 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: 73 YR
• Patient Weight: 136