MAUDE Adverse Event Report: STRYKER GMBH UNKNOWN_SELZACH_PRODUCT; IMPLANT

Catalog Number UNK_SEL

Device Problem Split (2537)

Patient Problems Cyst(s) (1800); Pain (1994)

Event Date 07/03/2015

Event Type  Injury  

Event Description

Patient experiencing pain.Primary surgery, 2011.Revision surgery, (b)(6) 2015.Patient was revised due to pain.Patient had lateral cysts, poly split in half.

Manufacturer Narrative

The reported device was manufactured and distributed by small bone innovation, inc., (b)(4) and implanted prior to howmedica osteonics corp.¿s purchase of certain assets of sbi on august 1, 2014.Stryker became legal manufacturer of this product on april 1, 2015 and has taken the responsibility for medical device reporting.Unknown star poly.Device will not be returned.If additional information becomes available it will be provided on a supplemental report.

Manufacturer Narrative

Evaluation revealed the mobile bearing (poly) to be the subject product.As neither the products itself nor the catalogue number is available, an investigation could not be performed.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 behavior 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¿ (1).¿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¿.(2).The key factor regarding the longevity of the polyethylene sliding core is the correct alignment of the implant components ¿to assure even distribution of forces on the polyethylene liner during gait¿ (3).The tibial and the talar component of the star ankle prosthesis have to be positioned ¿parallel to one another¿.A misalignment (especially greater than 5 degrees) ¿between the tibia and talus will cause increased stress and wear on the polyethylene component, greatly increasing the risk of failure of the polyethylene and loosening of the other components¿ (3).With respect to the available medical data a medical review was not possible.It could therefore not be determined whether the star components had been implanted in alignment respectively if edge / eccentric loading had been applied on the polyethylene sliding core.Based on the above information and referring to that no deviation was found in the manufacturing documents the breakage of the polyethylene sliding core was not related to a deficiency of the device, but was most likely linked to a fatigue fracture.Fatigue fracture of the implants is listed in the ifu as an adverse effect.With respect to the diagnosed ¿cystic bone quality¿, cyst formation had already been clinically assessed by a hcp: cyst formation (bone resorption) (0 ¿ 16 %): spontaneous bone resorption and cyst formation represents a significant problem in ankle arthroplasty.The symptoms may be mild and will not require specific surgical measures, but in many cases revision surgery with bone grafting may be required.In advanced cases cyst formation may cause a collapse of the arthroplasty requiring implant removal and ankle fusion (4).Additionally an evaluation by a product expert from the development department with respect to cyst formation.He stated that ¿this is a known complication and risk in the scientific literature.The exact source is unknown.Researchers believe that it is due to poly wear debris and/or fluid hydraulic pressure in the joint.¿ based on the sparse information available the exact cause of the event could not be determined.Surgical intervention (revision / removal) is listed in the ifu as an adverse effect.In case further relevant information should become available, we reserve the right to update the investigation and change the root cause.

Event Description

Patient experiencing pain.Primary surgery, 2011.Revision surgery, (b)(6) 2015.Patient was revised due to pain.Patient had lateral cysts, poly split in half.

• Brand Name: UNKNOWN_SELZACH_PRODUCT
• Type of Device: IMPLANT
• 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: anna jusinski ; 325 corporate drive; mahwah, NJ 07430 ; 2018315000
• MDR Report Key: 4951807
• MDR Text Key: 6196738
• Report Number: 0008031020-2015-00342
• Device Sequence Number: 1
• Product Code: HRS
• Combination Product (y/n): N
• Reporter Country Code: US
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Other,other
• Reporter Occupation: Other
• Type of Report: Initial,Followup
• Report Date: 07/07/2015

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 07/30/2015
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Lay User/Patient
• Device Catalogue Number: UNK_SEL
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: No
• Date Manufacturer Received: 10/15/2015
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• 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: 78 YR
• Patient Weight: 236