MAUDE Adverse Event Report: STANMORE IMPLANTS WORLDWIDE JTS, PROXIMAL TIBIA REPLACEMENT, AXLE CAP; PROSTHESIS, KNEE, FEMOROTIBIAL, CONSTRAINED, CEMENTED, METAL/POLYMER

Catalog Number UNK_STM

Device Problems Fracture (1260); Unintended Movement (3026)

Patient Problem Ambulation Difficulties (2544)

Event Date 04/07/2022

Event Type  Injury  

Manufacturer Narrative

It was noted that the device is not available for evaluation.Should additional information become available, it will be provided in a supplemental report upon completion of the investigation.Review of the device history records indicate devices were manufactured and accepted into final stock with no relevant reported discrepancies.There have been no other similar events for the lot referenced.Device not returned.

Event Description

The following was reported for the patient's left distal femoral jts: "the initial surgery has took place in (b)(6) 2020.In the end of (b)(6) 2022 the patient went to the hospital with the complaints.X-rays shows the axle migration.The revision surgery has took place in (b)(6) 2022 with replacement of bushes, bumper, axle and axle cap.It was found that the medial ring of the tibial component was cracked.In this regard, the axle and the axle cap were fixed laterally.According to the surgeon, the patient denies a fall or other type of traumatization of the operated limb.".

Event Description

The following was reported for the patient's left distal femoral jts: "the initial surgery has took place in april 2020.In the end of the february 2022 the patient went to the hospital with the complaints.X-rays shows the axle migration.The revision surgery has took place in (b)(6) 2022 with replacement of bushes, bumper, axle and axle cap.It was found that the medial ring of the tibial component was cracked.In this regard, the axle and the axle cap were fixed laterally.According to the surgeon, the patient denies a fall or other type of traumatization of the operated limb." update 30 june 2022: x ray review states : " [.] during revision surgery, it was found that axle and bumper pad has broken, and the medial ring has cracked [.] ".Update 20 july 2022: the intraoperative imaging provided by the sales rep was reviewed and confirmed the axle cap in situ was inserted the wrong way round.It is unclear if the intraoperative imaging provided was of the new axle cap that was recently inserted on the (b)(6) 2022 or the axle cap of pin 22284 which inserted back on the (b)(6) 2020 that was going to be explanted.

Manufacturer Narrative

Corrected data - d1.Reported event: an event regarding user error involving an unknown jts, proximal tibial replacement, axle cap was reported.The event was confirmed by x ray review.Method & results: device evaluation and results: provided images show the tibial component has a small slit crack/fracture on the hinge.The second image shows the axle cap inserted into the hinge is incorrectly orientated.The third image of the explanted device shows the axle has chipped and fractured.A small piece of the axle has fractured off.The bumper bad looks worn and deformed, a piece of the bumper has fractured on the left side, it is almost hanging off.Clinician review: a review of the provided x-rays by a clinical consultant indicated: the implant in situ was for jts proximal tibial replacement which was inserted on 02apr2020.The surgeon reported axle migration.During revision surgery, it was found that axle and bumper pad has broken, and the medial ring has cracked.The x-ray images provided show that the axle has backed out medially.The photos taken during revision surgery show the axle was broken with a free metal piece, the wear of the medial bumper pad, and a crack of the medial ring of the tibial component.Therefore, the radiographic image and photo review can confirm the clinical report and reason for revision.Device history review: a review of the product history records could not be performed as the lot / batch information was not provided.Complaint history review: a complaint history review could not be performed as the lot / batch information was not provided.Conclusion: the intraoperative imaging provided by the sales rep was reviewed with a senior principal engineer and senior design team manager confirmed the axle cap in situ was inserted the wrong way round.It is unclear if the intraoperative imaging provided was of the new axle cap that was recently inserted on the (b)(6) 2022 or the axle cap of pin 22284 which inserted back on the (b)(6) 2020 that was going to be explanted.Nonetheless incorrect orientation can cause "the axle to not [.] be retained in the axle hole correctly which will result in instability and eventual fracture [.]".The exact cause of the reported fracture could not be determined because insufficient information was provided.Additional information including operative reports, pathology reports, progress notes, and return of the device are needed to fully investigate the event.If further information becomes available or the product is returned, this investigation will be re-opened.Catalog numbers and lot codes of other devices listed in this report: jts, proximal tibia replacement, axle pin 22284.Jts, proximal tibia replacement, bumper pad b22513.It cannot be determined which, if any of these devices may have caused or contributed to the patient's experience.

• Brand Name: JTS, PROXIMAL TIBIA REPLACEMENT, AXLE CAP
• Type of Device: PROSTHESIS, KNEE, FEMOROTIBIAL, CONSTRAINED, CEMENTED, METAL/POLYMER
• Manufacturer (Section D): STANMORE IMPLANTS WORLDWIDE; 210 centennial avenue; centennial park, elstree; borehamwood WD6 3 SJ; UK WD6 3SJ
• Manufacturer (Section G): STANMORE IMPLANTS WORLDWIDE; 210 centennial avenue; centennial park, elstree; borehamwood WD6 3 SJ; UK WD6 3SJ
• Manufacturer Contact: diana rogers ; 210 centennial avenue; centennial park, elstree; borehamwood WD6 3-SJ ; UK WD6 3SJ ; 2082386500
• MDR Report Key: 14468664
• MDR Text Key: 292349921
• Report Number: 3004105610-2022-00081
• Device Sequence Number: 1
• Product Code: KRO
• Combination Product (y/n): N
• Reporter Country Code: RS
• PMA/PMN Number: K092138
• 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: 08/22/2022

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Health Professional
• Device Expiration Date: 09/30/2020
• Device Catalogue Number: UNK_STM
• Device Lot Number: PIN 22284
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Initial Date Manufacturer Received: 04/29/2022
• Initial Date FDA Received: 05/23/2022
• Supplement Dates Manufacturer Received: 07/28/2022
• Supplement Dates FDA Received: 08/22/2022
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 03/13/2020
• 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): Hospitalization; Required Intervention
• Patient Age: 21 YR
• Patient Sex: Male