MAUDE Adverse Event Report: STRYKER GMBH TALAR COMP,SINGLE COATED US VERS SMALL, LEFT; PROSTHESIS, KNEE, FEMOROTIBIAL, UNICOMPARTMENTAL, SEMI-CONSTRAINED, METAL/POLYME

Catalog Number 400255

Device Problem Device Slipped (1584)

Patient Problem Pain (1994)

Event Date 11/30/2015

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.

Event Description

Patient presented with pain and swelling throughout left ankle.Patient was revised and the mobile bearing was removed, and the talar component was loose and removed.A cement spacer and mobile bearing was placed in ankle.Patient had sub-talar fusion prior to star implant.Gray material was in the peri ankle space and thought to be metalosis, mobile bearing and talar component were sent to pathology for analysis.Interoperatively the sub-talar screw showed visible wear and the posterior portion of the talar component showed wear.No implants will be returned to stryker.

Manufacturer Narrative

Referring to the product inquiry both the talar component and the sliding core are stated to be the subject products.No further associated product was reported.The devices were not returned for evaluation; the sales rep stated: ¿no implants will be returned to stryker.¿ failures in material or manufacturing of the affected implants were not found.The affected items were documented faultless prior to distribution.The sales rep stated that he has neither access to revision operative reports nor to the pathology / lab report.Regarding the ¿checklist customer / dqf 13-003¿, which was sent out by stryker in order to be filled out by the customer resp.The sales rep, he stated: ¿i do not have any answers for the attached¿.Implant loosening and subsidence had already been clinically assessed by a consultant hcp: ¿in most cases, the trabecular bone structure will be adapted to the plasma spray coated surface of the metallic components in a remodeling process correspondent to the lines of forces resulting in a stable connection between bone and the metallic components.But, in the course of time this integration of the endoprosthesis to the bone structure may fail due to any reason and result in loosening of one or both metallic components.Septic and aseptic implant loosening is the main failure mode in total arthroplasty of the ankle joint.Depending on the individual kind of failure, it is possible to revise the endoprosthesis and to exchange the affected component(s)¿ ¿subsidence caused by collapse of the tibial bone or the talar bone structures or loss of the ligament stability of the ankle joint is a rare event, but will require removal of the endoprosthesis and ankle fusion.¿ the root cause of implant loosening is nominated in the scientific literature: rotational stresses are placed on the tibial component during ambulation for a number of reasons.Normal hindfoot kinematics at heel strike involves tibial internal rotation linked to calcaneal eversion.Later in gait, external rotation of the pelvis and leg is linked to hindfoot inversion.This rotational linkage occurs through the oblique axis of the subtalar joint but by necessity is transmitted through the ankle joint.Abnormal rotational stresses may occur as well.Cylindrical implant designs do not take into account the differential curvature of radius of the medial and lateral talus and may put rotational stress on the implant during ankle motion.Malpositioning of the implant in relation to the rotational axis of the ankle or malpositioning of the tibial implant in relation to the talar implant may result in rotational stresses as well.The magnitude of these rotational stresses and their clinical signi fi cance is unknown.However, in contrast to vertical load, which compresses bone¿implant interface, rotational forces and side-to-side shear forces do not contribute to implant stability and may lead to implant loosening, polyethylene wear, or strain on surrounding ligaments.Implant subsidence is furthermore nominated in the scientific literature: ¿component subsidence may result from poor bone quality, osteolysis-related bone loss, or poor component positioning.Early subsidence of a millimetre or less may represent settling of the components into a stable position and does not portend failure of the implants.A rsa study of 15 rheumatoid patients had shown that ¿tibial components tend to subside into dorflexion, valgus, and proximally by less than a millimetre during the first 3 months, and stabilze by 6 months¿.Since most designs do not allow axial impaction of the component, this settling may represent the implant finding a stable position as weight-bearing is allowed.Patients with severe osteoporosis or avascular necrosis may not have strong enough bone to support the placement of a total ankle replacement.¿ ¿a number of factors affect risk of subsidence.Initial implant positioning may contribute to subsidence.Subsidence tends to occur in the anterior distal tibia, dorsiflexing the tibial component, or in the anterior talus or posterior talus.Anterior translation of the talar component or excessive dorsiflexion of the tibial component should be avoided to prevent overloading the bone in these at risk areas.¿ since the manufacturing documents showed no deviation and based on the medical experiences cited the event was not linked to a deficiency of the devices.However, since the devices were not available for a physical examination and only based on the limited information given the exact root cause of the reported event could not be determined.In this case the hospital report dated (b)(6) 2015 clearly states the root cause of the reported infection: ¿¿ankle aspirate cultured (b)(6) reveals staph epidermidis¿¿, which is considered a typical hospital acquired infection.A similar case was presented to a consulting hcp who stated: ¿it can be concluded with absolute certainty that the reported hospital pathogen ¿staphylococcus epidermidis¿ did not originate from the originally packed implants reported, but was rather caused by poor hygiene in the hospital.¿ thus, a review of the event in line with the ¿checklist investigator¿ according to dqf 13-002 was deemed unnecessary.Based on the information given the root cause of the reported infection ¿staphylococcus epidermidis¿) is not linked to a deficiency of the devices, but is rather considered user related (typical hospital acquired infection - caused by poor hygiene in the hospital).No non-conformity was identified.

Event Description

Patient presented with pain and swelling throughout left ankle.Patient was revised and the mobile bearing was removed, and the talar component was loose and removed.A cement spacer and mobile bearing was placed in ankle.Patient had sub-talar fusion prior to star implant.Gray material was in the peri ankle space and thought to be metallosis, mobile bearing and talar component were sent to pathology for analysis.Interoperatively the sub-talar screw showed visible wear and the posterior portion of the talar component showed wear.No implants will be returned to stryker.

• Brand Name: TALAR COMP,SINGLE COATED US VERS SMALL, LEFT
• 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: 5316237
• MDR Text Key: 34070233
• Report Number: 0008031020-2015-00547
• 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: 11/30/2015

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 12/21/2015
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Lay User/Patient
• Device Expiration Date: 10/31/2019
• Device Catalogue Number: 400255
• Device Lot Number: 1435082
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 03/18/2016
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 10/01/2014
• 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: 60 YR
• Patient Weight: 95