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

Catalog Number UNK_STM

Device Problem Malposition of Device (2616)

Patient Problems Pain (1994); Ambulation Difficulties (2544); Unequal Limb Length (4534)

Event Date 08/28/2020

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 relevant reported discrepancies.Not returned.

Event Description

A patient specific prescription form was received for the patient's right distal femur (jts).Appointment notes from a lengthening procedure on (b)(6) 2020 note the following: "today, she has knee pain with hip rotation and knee flexion.She also complains of a significant limp.She has pain when walking and with activity.She is wearing a knee brace on the right knee for stability.She has occasional tingling in both heels with prolonged activity.The patient presented with a 4 cm leg length discrepancy in the right leg.She currently has extendable implant.Can only be lengthened 0.5 cm at this time.She would need to undergo an exchange implant to effectively normalize her limbs over a 12-18 month.At the same time, the tibial component needs to be revised to a proper tibial cut to place stem in the proper position.She underwent a successful lengthening today of 0.5 cm." the distal femur component is being investigated for leg length discrepancy.The tibial component is being investigated for malposition.

Manufacturer Narrative

Reported event: an event regarding malposition involving a jts, distal femur, tibial 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: a review of the provided x-rays by a clinical consultant indicated: the implant in situ was for a jts distal femoral replacement which was inserted in 2014.The surgeon reported that the patient had leg length discrepancy, knee pain and malposition of the tibial stem.The x-rays provided showed that the stem has been extended by 40mm, and another 0.5 mm has been extended according to the event description, which indicates that the implant has almost reached to its maximum capacity of 50 mm.The images also show that the right leg was 40mm shorter, in which the femur was 25mm shorter and the tibia was 15mm shorter.However, the additional images provided recently in ppt didn¿t include immediate post-op x-ray, therefore it is hard to confirm whether the tibia shortening is due to over resection of the tibial plateau in the surgery or damage of the epiphyseal grow zone causing tibia bone stop to grow after surgery.The tibial stem was tilted towards lateral and posterior causing resorption of the cortical bone and bone defects.Therefore, the radiographic review can confirm the clinical report and reason for revision.Device history review: review of the product history records indicate (b)(4) device was manufactured and accepted into final stock on 01 july 2014 with no reported discrepancies.Complaint history review: there have been no other events for the lot referenced.Conclusion: the exact cause of the event could not be determined because insufficient information was provided.Additional information including operative reports, pathology reports, progress notes, x-rays 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.

Event Description

A patient specific prescription form was received for the patient's right distal femur (jts).Appointment notes from a lengthening procedure on (b)(6)2020 note the following: "today, she has knee pain with hip rotation and knee flexion.She also complains of a significant limp.She has pain when walking and with activity.She is wearing a knee brace on the right knee for stability.She has occasional tingling in both heels with prolonged activity.The patient presented with a 4 cm leg length discrepancy in the right leg.She currently has extendable implant.Can only be lengthened 0.5 cm at this time.She would need to undergo an exchange implant to effectively normalize her limbs over a 12-18 month.At the same time, the tibial component needs to be revised to a proper tibial cut to place stem in the proper position.She underwent a successful lengthening today of 0.5 cm." the distal femur component is being investigated for leg length discrepancy.The tibial component is being investigated for malposition.

• 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
• MDR Report Key: 10566329
• MDR Text Key: 207907690
• Report Number: 3004105610-2020-00148
• Device Sequence Number: 1
• Product Code: KRO
• Combination Product (y/n): N
• PMA/PMN Number: K133152
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: health professional,other
• Type of Report: Initial,Followup
• Report Date: 01/04/2021

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: 12/31/2014
• Device Catalogue Number: UNK_STM
• Device Lot Number: PIN 18775
• Was Device Available for Evaluation?: No
• Initial Date Manufacturer Received: 08/28/2020
• Initial Date FDA Received: 09/22/2020
• Supplement Dates Manufacturer Received: 12/21/2020
• Supplement Dates FDA Received: 01/04/2021
• Is This a Reprocessed and Reused Single-Use Device?: No
• Patient Sequence Number: 1
• Patient Outcome(s): Hospitalization; Required Intervention
• Patient Age: 14 YR
• Patient Weight: 72