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

Model Number PIN 20199

Device Problems Use of Device Problem (1670); Failure to Advance (2524)

Patient Problems Cancer (3262); Unequal Limb Length (4534)

Event Date 04/03/2019

Event Type  malfunction  

Manufacturer Narrative

An investigation is being performed in an attempt to identify the cause of the event.Should additional information become available it will be reported in a supplemental report.

Event Description

It was reported, "the expansion of the prosthesis went off fine as recommended for 20 minutes (5 mm).The auditory feedback with a stethoscope was also ok as was patients perception of the tightness.However the post extension x ray doesn't show the 5 mm very clearly.(there is a magnification factor involved)".

Event Description

It was reported, "the expansion of the prosthesis went off fine as recommended for 20 minutes (5 mm).The auditory feedback with a stethoscope was also ok as was patients perception of the tightness.However the post extension x ray doesn't show the 5 mm very clearly.(there is a magnification factor involved).".

Manufacturer Narrative

Reported event: an event regarding seizing involving a jts distal femur was reported.The event was confirmed by medical review.Method and results: product evaluation and results: not performed as no items were returned.Clinician review: a review of the provided x-rays by clinical consultant indicated: the implant in situ was for a jts distal femur, which was inserted on (b)(6) 2016.The surgeon reported that after 20 mins of extension of the prosthesis, in which nothing unusual has happened and the patient has felt the tightness of the leg, but the expected 5 mm extension of the prosthesis was not shown on the x-rays.The x-rays provided through the email showed that in comparison of the pre and post extension of the prosthesis the implant profile has not been changed which indicates that the prosthesis has not been extended at all.Therefore, the radiographic assessment has confirmed the clinical report.Product history review: review of the product history records indicate (b)(4) device was manufactured and accepted into final stock on 01jul2016 with no reported discrepancies.Complaint history review: based on the device identification the complaint databases were reviewed from 03apr2016 to present for similar reported events regarding seizing issues.There have been 16 other events reported.Siw will continue to monitor for trends.Conclusions: an event regarding seizing involving a jts distal femur was reported.The event was confirmed by medical review.The sr staff engineer reviewed the event and stated "typically if the orientation of the patient and the direction is correct, and you hear the mechanism, it is indicative that the lengthening has been performed successfully.However this does not bear out on the x-ray.It is possible that the mechanism may be being restricted by soft tissue ¿ we can increase the magnetic field strength generated by the device to give it more power." the exact cause of the event could not be determined because the retrieved implant, the primary operative report as well as patient history and follow up notes are needed to complete the investigation for determining root cause.No further investigation for this event is possible at this time as no devices and/or insufficient information was received by siw.If devices and/or additional information become available to indicate further evaluation is warranted, this record will be re-opened.Siw will continue to monitor for trends.Corrective action/preventive action: no action is required at this time as there is no indication to suggest a product non-conformity or unanticipated hazard.H3 other text: device remains implanted.

Manufacturer Narrative

Reported event: an event regarding seizing involving a jts distal femur was reported.The event was confirmed by medical review.Method and results: product evaluation and results: not performed as no items were returned.Clinician review: a review of the provided x-rays by clinical consultant indicated: the implant in situ was for a jts distal femur, which was inserted on (b)(6) 2016.The surgeon reported that after 20 mins of extension of the prosthesis, in which nothing unusual has happened and the patient has felt the tightness of the leg, but the expected 5 mm extension of the prosthesis was not shown on the x-rays.The x-rays provided through the email showed that in comparison of the pre and post extension of the prosthesis the implant profile has not been changed which indicates that the prosthesis has not been extended at all.Therefore, the radiographic assessment has confirmed the clinical report.Product history review: review of the product history records indicate 1 device was manufactured and accepted into final stock on 01jul2016 with no reported discrepancies.Complaint history review: based on the device identification the complaint databases were reviewed from 03apr2016 to present for similar reported events regarding seizing issues.There have been 16 other events reported.Siw will continue to monitor for trends.Conclusions: an event regarding seizing involving a jts distal femur was reported.The event was confirmed by medical review.The sr staff engineer reviewed the event and stated "typically if the orientation of the patient and the direction is correct, and you hear the mechanism, it is indicative that the lengthening has been performed successfully.However this does not bear out on the x-ray.It is possible that the mechanism may be being restricted by soft tissue ¿ we can increase the magnetic field strength generated by the device to give it more power." the exact cause of the event could not be determined because the retrieved implant, the primary operative report as well as patient history and follow up notes are needed to complete the investigation for determining root cause.No further investigation for this event is possible at this time as no devices and/or insufficient information was received by siw.If devices and/or additional information become available to indicate further evaluation is warranted, this record will be re-opened.Siw will continue to monitor for trends.Corrective action/preventive action: no action is required at this time as there is no indication to suggest a product nonconformity or unanticipated hazard.

Event Description

It was reported, "the expansion of the prosthesis went off fine as recommended for 20 minutes (5 mm).The auditory feedback with a stethoscope was also ok as was patients perception of the tightness.However the post extension x ray doesn't show the 5 mm very clearly.(there is a magnification factor involved)" update 12/august/2020 : as reported by surgeon: "from march till date, given the covid 19 situation in india and the lockdown, things were at a stand still.We weren't able to get access to the extender mechanism as well during this period.After a considerable wait, i have been able to attempt another expansion this week for the patient.I have tried increasing the power of the coil after speaking to other surgeons in india regarding similar experiences.Also tried gentle traction on the limb.However, the prosthesis remains in the same state as before and isn't expanding.".

Event Description

It was reported, "the expansion of the prosthesis went off fine as recommended for 20 minutes (5 mm).The auditory feedback with a stethoscope was also ok as was patients perception of the tightness.However the post extension x ray doesn't show the 5 mm very clearly.(there is a magnification factor involved)".Update 12/august/2020 : as reported by surgeon: "from march till date, given the covid 19 situation in india and the lockdown, things were at a stand still.We weren't able to get access to the extender mechanism as well during this period.After a considerable wait, i have been able to attempt another expansion this week for the patient.I have tried increasing the power of the coil after speaking to other surgeons in india regarding similar experiences.Also tried gentle traction on the limb.However, the prosthesis remains in the same state as before and isn't expanding.".Update (b)(6) 2022: another unsuccessful lengthening procedure.Update - "after a few more attempts of lengthening the leg [.] it was concluded that further attempts would be ceased.Future options were discussed with the surgeon [.] the family wanted one last attempt of lengthening with a new drive unit and with product experts present before discussing these surgical options further.This action has now been completed and the surgeon will discuss future options with the patient and his family [.]".

Manufacturer Narrative

Reported event: an event regarding seizing involving a jts distal femur was reported.The event was confirmed by medical review.Method and results: product evaluation and results: not performed as no items were returned.Clinician review: a review of the provided x-rays by clinical consultant indicated: the implant in situ was for a jts distal femur, which was inserted on 15th july 2016.The surgeon reported that after 20 mins of extension of the prosthesis, in which nothing unusual has happened and the patient has felt the tightness of the leg, but the expected 5 mm extension of the prosthesis was not shown on the x-rays.The x-rays provided through the email showed that in comparison of the pre and post extension of the prosthesis the implant profile has not been changed which indicates that the prosthesis has not been extended at all.Therefore, the radiographic assessment has confirmed the clinical report.Product history review: review of the product history records indicate the device was manufactured and accepted into final stock with no reported discrepancies.Complaint history review: there have been 16 other events reported.Siw will continue to monitor for trends.Conclusions: an event regarding seizing involving a jts distal femur was reported.The event was confirmed by medical review.On the (b)(6) 2020, the surgeon gave further information about the patient "implantation was in (b)(6) 2016, first expansion attempt was in (b)(6) 2019 since the patient didn't have limb length discrepancy till then.We have attempted expansion again in september 2019 and (b)(6) 2020." the surgeon also reported that only 1 mm was achieved on the very first expansion, currently the patient has 2 cm of limb length discrepancy.The surgeon also confirmed that the patient's leg was correctly positioned inside the coil, that the right setting (a) was chosen and that he tried to boost the jts drive unit.The sr design manager reviewed the event and stated, since the implant was not extended in the 2.5 years from the initial implantation until the extension attempt, there may have been some fibrous tissue build up around the device which is preventing the extension; however, the exact cause of the event could not be determined.Technical review : "taking into consideration all known factors, the device was working as expected on supply to the customer.The device has grown by approximately 2mm, however for an unknown reason, the device is no longer capable of further extension.".No further investigation for this event is possible at this time as no devices and/or insufficient information was received by siw.If devices and/or additional information become available to indicate further evaluation is warranted, this record will be re-opened.

• Brand Name: DISTAL FEMUR JTS
• 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: 8572411
• MDR Text Key: 146380995
• Report Number: 3004105610-2019-00056
• Device Sequence Number: 1
• Product Code: KRO
• Combination Product (y/n): N
• Reporter Country Code: IN
• PMA/PMN Number: K133152
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Other,Health Professional
• Reporter Occupation: Physician
• Type of Report: Initial,Followup,Followup,Followup
• Report Date: 01/25/2023

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 05/02/2019
• Is this an Adverse Event Report?: No
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Expiration Date: 12/31/2016
• Device Model Number: PIN 20199
• Device Catalogue Number: UNK_STM
• Device Lot Number: PIN 20199
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 01/25/2023
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 07/01/2016
• 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
• Treatment: SMBPR00 (B15394) BUMPER PAD; SMBSH00 (B15122) BUSHES; SMCIC01 (B15612) AXLE CAP; SMTBC00G (B15615) PASSIVE TIBIAL BEARING
• Patient Outcome(s): Other
• Patient Age: 11 YR
• Patient Sex: Male
• Patient Weight: 40 KG