MAUDE Adverse Event Report: STANMORE IMPLANTS WORLDWIDE DISTAL FEMUR JTS - TIBIAL COMPONENT; PROSTHESIS, KNEE, FEMOROTIBIAL, CONSTRAINED, CEMENTED, METAL/POLYMER

Catalog Number UNK_STM

Device Problems Adverse Event Without Identified Device or Use Problem (2993); Unintended Movement (3026)

Patient Problem Unequal Limb Length (4534)

Event Date 09/20/2021

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

As reported: "the patient was brought in for his penultimate lengthening prior to having his device revised.The implant failed to lengthen because the gearbox would freeze as soon as it reached full speed (rpm).This gearbox had been "sticky" before and the surgeon tried to boost the power on the drive unit, because that had worked in the past.Unfortunately, it didn't work this time.They tried reversing the polarity of the drive unit to reverse the spin of the gearbox, but it froze when spinning in reverse too.The surgeon was not able to lengthen the patient's prosthesis despite exhausting all normal troubleshooting options.We plan on revision to a static implant and will revise his tibial implant as well." update 23/september/2021 wg: additional information provided by sales rep: "we are still 1cm short of terminal extension (8cm extension out of the max 9cm).The patient has reached skeletal maturity.There was a lengthening attempted on (b)(6) 2021.It was ascertained that the patient was 2.1cm shorter in his affected limb.So, the decision was made to lengthen his device the additional 1cm and replace the distal component with the jts motor with a static distal component that would account for the full 9cm of extension being achieved.He¿s suffered some physeal arrest in the affected tibia it is certainly a contributing factor (for limb length discrepancy.If you review that standing ap xray, the affected tibia is shorter than the contralateral tibia.".

Event Description

As reported: "the patient was brought in for his penultimate lengthening prior to having his device revised.The implant failed to lengthen because the gearbox would freeze as soon as it reached full speed (rpm).This gearbox had been "sticky" before and the surgeon tried to boost the power on the drive unit, because that had worked in the past.Unfortunately, it didn't work this time.They tried reversing the polarity of the drive unit to reverse the spin of the gearbox, but it froze when spinning in reverse too.The surgeon was not able to lengthen the patient's prosthesis despite exhausting all normal troubleshooting options.We plan on revision to a static implant and will revise his tibial implant as well." update 23/september/2021 wg: additional information provided by sales rep: ".We are still 1cm short of terminal extension (8cm extension out of the max 9cm).The patient has reached skeletal maturity.There was a lengthening attempted on (b)(6) 2021.It was ascertained that the patient was 2.1cm shorter in his affected limb.So, the decision was made to lengthen his device the additional 1cm and replace the distal component with the jts motor with a static distal component that would account for the full 9cm of extension being achieved.He¿s suffered some physeal arrest in the affected tibia it is certainly a contributing factor (for limb length discrepancy.If you review that standing ap xray, the affected tibia is shorter than the contralateral tibia.".

Manufacturer Narrative

Reported event: an event regarding patient factors involving a jts, distal femur replacement was reported.The event was confirmed by x ray review.Method & results: device evaluation and results: not performed as product was not returned.Clinician review: the implant in situ was for a jts distal femoral replacement which was inserted on (b)(6) 2013.The surgeon reported that the implant has ceased to extend, and the affected leg is shorter.The x-ray and ct images provided show that the implant has been extended by 80mm, which hasn¿t reached its maximum capacity of 90mm.Both affected femur and tibia are shorter than the opposite side, which confirms the clinical report and reason for revision.Device history review: review of the product history records indicate the device was manufactured and accepted into stock with no reported relevant discrepancies.Complaint history review: there have been 1 other event for the lot referenced.This is for the same device, same patient.Conclusion: 23sep2021 it was reported by the sales rep: "there was a lengthening attempted on (b)(6) 2021.It was ascertained that the patient was 2.1cm shorter in his affected limb [.] he¿s suffered some physeal arrest in the affected tibia.It is certainly a contributing factor (for limb length discrepancy.If you review that standing ap x ray on page 7, the affected tibia is shorter than the contralateral tibia." 21dec2021 it was reported by the clinical consultant " [.] the affected leg is shorter.The x-ray and ct images provided show [.] both affected femur and tibia are shorter than the opposite side which confirms the clinical report and reason for revision." the exact cause of the event could not be determined because insufficient information was provided.Additional information including operative reports, pathology reports, progress notes, are needed to fully investigate the event.If further information becomes available or the product is returned, this investigation will be re-opened.

• Brand Name: DISTAL FEMUR JTS - TIBIAL COMPONENT
• 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: 12632790
• MDR Text Key: 276417442
• Report Number: 3004105610-2021-00135
• Device Sequence Number: 1
• Product Code: KRO
• Combination Product (y/n): N
• Reporter Country Code: US
• PMA/PMN Number: K133152
• 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: 01/17/2022

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 10/14/2021
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: No
• Device Operator: Health Professional
• Device Expiration Date: 10/31/2013
• Device Catalogue Number: UNK_STM
• Device Lot Number: PIN 17760
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 01/13/2022
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 04/20/2013
• 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): Other
• Patient Age: 17 YR
• Patient Sex: Male