MAUDE Adverse Event Report: SMITH & NEPHEW ORTHOPAEDICS AG RT-PLUS MOD FEMORAL COMP. LEFT 4 CEM; PROSTHESIS, KNEE, FEMOROTIBIAL, NON-CONSTRAINED, CEMENTED, METAL/POLYMER

Catalog Number 75005555

Device Problems Mechanical Jam (2983); Mechanics Altered (2984); Loosening of Implant Not Related to Bone-Ingrowth (4002)

Patient Problems Loss of Range of Motion (2032); Arthralgia (2355); Inadequate Osseointegration (2646); No Clinical Signs, Symptoms or Conditions (4582)

Event Date 11/02/2023

Event Type  Injury  

Manufacturer Narrative

Internal complaint reference case-(b)(4).

Event Description

It was reported that, after a tka surgery in which the patient experienced implant failure, a revision surgery was performed on (b)(6) 2023, in which a defective/blocked hinge mechanism was found on the loose femoral component.Health status of the patient is unknown.

Manufacturer Narrative

D1, d2a, d2b, d4: updated.

Manufacturer Narrative

Additional information: d6b (explanted date added), d10 (concomitant devices added), h5 (labelled as single use), h6 (component code, type of investigation, investigation findings, investigation conclusions).Results of investigation: it was reported that, after a total knee arthroplasty in which the patient experienced implant failure, a revision surgery was performed on (b)(6) 2023, in which a defective/blocked hinge mechanism was found on the loose femoral component.The complaint devices (75005555 - rt-plus mod femoral comp, 75005516 - 160mm stem, 2x 75005579 - distal block) were returned for investigation.The additional rt-plus tibial insert 4/8mm 75005482 and rt-plus mod tibial component 4 cem 75005560 were not returned for investigation.A visual evaluation of the assembled femoral component was performed.Due to the extensive amount of cement that was present around the implant, the lot numbers of the devices could not be read.Upon visual inspection, slight scratches are visible at the anterior shield, potentially originating from device explantation.Additionally, some bone cement remains are visible at the interface to the rigid rod where the hinge joint is located.Based on the performed visual inspection, it cannot be excluded, that further bone cement is situated inside the hinge joint, preventing the rigid rod from a smooth rotation.The functional evaluation was performed, by testing the rotation of the rigid rod within the hinge knee according to the corresponding inspection instruction with a test weight.The test weight, attached to the rigid rod should fall into a vertical position when starting in a horizontal position.However, this did not happen with the present device.Hence, the reported failure mode could be confirmed.A thorough dimensional analysis of the femoral component and the pe casing, in terms of obtaining any deviation from the manufacturing specifications, was not possible since these components cannot be measured separately.However, the accessible dimensions, relevant for the hinge rotation, were measured as far as possible.Apart from the overall width of the pe-casing, all dimensions were measured within specification.The overall width of the pe-casing was measured flush and in alignment with the femoral box width.This explains the exact same measurement outcome of the femoral box and the pe-casing.For a more precise measurement of the pe-casing, the femoral device would need to be disassembled.Hence, it cannot be concluded that the pe-casing had any manufacturing related dimensional deviation which could have contributed to the reported stiffness of the joint.A review of the production documentation could not be performed due to the missing batch number.Additionally, the complaint history review was performed on product number level.There was no additional complaint reported for the same product no.(75005555) over the past 12 months with a similar failure mode.A review of past corrective actions was performed.No further escalation is required.A review of the risk management documentation verifies the failure mode, occurrence and severity of the reported issue.Insufficient information was made available to determine the revision of the "instruction for use" applicable to the device at the time of manufacturing.However, a review of the current revision was conducted and it revealed that the instruction for use (lit.No.12.24, ed.03/21) mentions that for implants intended for cemented fixation, the surgeon must follow the cement manufacturer instructions concerning the preparation, cementing technique and recommendations for use.Prior to wound closure, the surgical site has to be thoroughly cleaned from foreign particles, bone cement, bone chips or other debris.Furthermore "loosening of implant not related to bone-ingrowth" of the component is listed as a ¿potential medical device problem¿ in combination with the implantation of a hip prosthesis.A clinical evaluation was performed.The gained blood sample was not indicating an infection.The clinical root cause of the blocked hinge cannot be confirmed.However, the blocked hinge could lead to loosening of the implant and the need for revision.Due to the missing batch number, it is not possible to investigate whether the reported devices met manufacturing specifications upon release for distribution.The root cause of the reported event remains undetermined.However, it cannot be excluded that excess bone cement, situated inside the hinge joint is preventing the rigid rod from a smooth rotation resulting in a loosening of the device.The need for further actions is not indicated.Nevertheless, smith+nephew will continue to monitor this device for similar issues.The returned devices will be retained.Corrected data: d9&h3 (sample returned for analysis), h6 (health effect - clinical code, health effect - impact code, medical device problem code).

• Brand Name: RT-PLUS MOD FEMORAL COMP. LEFT 4 CEM
• Type of Device: PROSTHESIS, KNEE, FEMOROTIBIAL, NON-CONSTRAINED, CEMENTED, METAL/POLYMER
• Manufacturer (Section D): SMITH & NEPHEW ORTHOPAEDICS AG; schachenallee 29; aarau CH-50 00; SZ CH-5000
• Manufacturer (Section G): SMITH & NEPHEW ORTHOPAEDICS AG; schachenallee 29; aarau CH-50 00; SZ CH-5000
• Manufacturer Contact: holly topping ; 7000 west william cannon drive; austin, TX 78735 ; 5123913905
• MDR Report Key: 18298532
• MDR Text Key: 330113793
• Report Number: 9613369-2023-00224
• Device Sequence Number: 1
• Product Code: HSX
• UDI-Device Identifier: 07611996042863
• UDI-Public: 7611996042863
• Combination Product (y/n): N
• Reporter Country Code: SZ
• Number of Events Reported: 1
• Summary Report (Y/N): N
• Report Source: Manufacturer
• Source Type: Other,Foreign,Health Professional,Company Representative
• Reporter Occupation: Physician
• Type of Report: Initial,Followup,Followup
• Report Date: 01/12/2024

1 Device was Involved in the Event

1 Patient was Involved in the Event

• Date FDA Received: 12/10/2023
• Is this an Adverse Event Report?: Yes
• Is this a Product Problem Report?: Yes
• Device Operator: Health Professional
• Device Catalogue Number: 75005555
• Device Lot Number: UNKNOWN
• Was Device Available for Evaluation?: Device Returned to Manufacturer
• Is the Reporter a Health Professional?: Yes
• Date Manufacturer Received: 01/11/2024
• Was Device Evaluated by Manufacturer?: Device Not Returned to Manufacturer
• 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: PN: 75005482 / LOT: UNKNOWN; PN: 75005516 / LOT: UNKNOWN; PN: 75005579 / LOT: UNKNOWN
• Patient Outcome(s): Required Intervention
• Patient Age: 74 YR