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

Catalog Number UNK_STM

Device Problems Adverse Event Without Identified Device or Use Problem (2993); Insufficient Information (3190)

Patient Problems Ambulation Difficulties (2544); Unequal Limb Length (4534)

Event Date 12/20/2021

Event Type  Injury  

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.Review of the device history records indicate devices were manufactured and accepted into final stock with no reported discrepancies.There have been no other events for the lot referenced.Not returned.

Event Description

A patient specific implant prescription form was received for the patient's left proximal tibia replacement jts.Noted on the form: "limb not extendible enough.Replacement of distal femur component.Op planned at (b)(6) 2022." update (b)(6) 2022: " there is no issue with the extension mechanism.The problem is the patient¿s growth itself: due to the fact that the patient grew a lot since the implantation, the tibia is (due to the extension mechanism) the same length as on the opposite side but the femur shows a significant length discrepancy which cannot be balanced with the extension mechanism.The issue is that the joint line is deteriorated and the patient has problems with the patella tracking".

Manufacturer Narrative

Reported event: an event regarding limb length discrepancy involving a jts proximal tibial, femoral stem 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 jts proximal tibial replacement which was inserted on (b)(6)2016.The surgeon reported leg length discrepancy due to fast growing of the patient.The ct scan provided shows that the length of the affect femur is 449mm which is 29mm shorter than the opposite femur which is 478mm.However, the affect tibial is 424mm which is 27mm longer than the opposite tibial which is 397mm.In overall, the affected lower limb has similar leg length as the opposite limb but the knee joint is much higher which might affect the patella tracking.Therefore, the radiographic review can confirm the clinical report and reason for revision.Device 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 no other events for the lot referenced.Conclusion it was confirmed " there is no issue with the extension mechanism.The problem is the patient¿s growth itself: due to the fact that the patient grew a lot since the implantation[.] the femur shows a significant length discrepancy which cannot be balanced with the extension mechanism".The device in situ is a jts, proximal tibia therefore the 'tibial' limb length discrepancy can be resolved via non invasive lengthening procedure, however the 'femoral' limb length discrepancy in the affected leg cannot.The clinical consultant confirmed this by completing a review of the x ray imaging provided ,stating " the affected femur is 449mm which is 29mm shorter than the opposite femur which is 478mm.However, the affected tibial is 424mm which is 27mm longer than the opposite tibial which is 397mm".The exact cause of the 'femoral' limb length discrepancy 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.

Event Description

A patient specific implant prescription form was received for the patient's left proximal tibia replacement jts.Noted on the form: "limb not extendible enough.Replacement of distal femur component.Op planned at (b)(6) 2022." update (b)(6) 2022: " there is no issue with the extension mechanism.The problem is the patient¿s growth itself: due to the fact that the patient grew a lot since the implantation, the tibia is (due to the extension mechanism) the same length as on the opposite side but the femur shows a significant length discrepancy which cannot be balanced with the extension mechanism.The issue is that the joint line is deteriorated and the patient has problems with the patella tracking".

• Brand Name: PROXIMAL TIBIAL JTS - DISTAL FEMORAL COMPONENT/ ASSEMBLY
• 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, NJ WD6 3-SJ ; UK WD6 3SJ ; 2018315000
• MDR Report Key: 13226274
• MDR Text Key: 283611727
• Report Number: 3004105610-2022-00004
• Device Sequence Number: 1
• Product Code: KRO
• Combination Product (y/n): N
• Reporter Country Code: AU
• 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
• Report Date: 03/31/2022

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: 05/31/2017
• Device Catalogue Number: UNK_STM
• Device Lot Number: PIN 20419
• Was Device Available for Evaluation?: No
• Is the Reporter a Health Professional?: Yes
• Initial Date Manufacturer Received: 12/20/2021
• Initial Date FDA Received: 01/11/2022
• Supplement Dates Manufacturer Received: 03/28/2022
• Supplement Dates FDA Received: 03/31/2022
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• Date Device Manufactured: 11/21/2016
• 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
• Patient Outcome(s): Hospitalization; Required Intervention
• Patient Age: 14 YR
• Patient Sex: Male
• Patient Weight: 50 KG