(259 days)
This device is indicated in knee arthroplasty for reduction or relief of pain and/or improved knee function in skeletally mature patients with severe knee pain and disability due to rheumatoid arthritis, osteoarthritis, primary and secondary traumatic arthritis, polyarthritis,collagen disorders, avascular necrosis of the femoral condyle or pseudogout, posttraumatic loss of joint configuration, particularly when there is patellofemoral erosion, dysfunction or prior patellectomy, moderate valgus, varus, or flexion deformities. This device may also be indicated in the salvage of previously failed surgical attempts if the knee can be satisfactorily balanced and stabilized at the time of surgery. This device system is designed for cement use only.
The Prolixus™ Cruciate Retaining (CR) Total Knee System consists of three primary components: Cruciate Retaining (CR) Femoral Component, Cruciate Retaining (CR) Tibial Insert, Patellar component and Tibial base plate.
The Prolixus™ CR components are described below:
PROLIXUSTMTotal Knee Cruciate Retaining (CR) Femoral Component
Prolixus™ Total Knee Cruciate Retaining (CR) Femoral Component is fabricated from cast cobalt-chromium-molybdenum alloy, and is intended for cemented application to replace the articulating surface of the distal femur. This cruciate retaining femoral component is utilized when total knee replacement is indicated, and accommodates the posterior cruciate ligament if it is present.
The Cruciate Retaining (CR) Femoral Component is available in right and left configurations, and six proportional sizes (sizes A to F) to accommodate differences in patient anatomy. The interior surface of the component is grit-blasted to increase surface roughness - this is intended to promote interdigitation of the polymethylmethacrylate (PMMA) bone cement with the surface texture and the apposing bone. This femoral component features cast-in pegs to help in femoral component placement, and to provide rotational stability.
PROLIXUS™ Cruciate Retaining (CR) Tibial Insert
The Cruciate Retaining (CR) Tibial Insert is neutral in configuration, and is available in six proportional sizes (sizes 1 to 6) and varying thicknesses (10mm, 12mm,14mm, 16mm, 18mm and 20 mm). The insert is fabricated from ultra high molecular weight polyethylene(medical grade PUR 1020 UHMPE) .The tibial insert is designed to accommodate the posterior cruciate ligament if it is present. There is a relief on the anterior aspect of the tibial insert to accommodate the patellar tendon and patellar fat pad.
PROLIXUS™ Tibial base plate
Stem tibial baseplate components (tibial baseplate) are made from Ti-The angled 6Al-4V titanium alloy. Tibial baseplates are available in 6 sizes (1 to 6).
PROLIXUS™ | Patellar components
patellar component is made from ultra high molecular weight The polyethylene(medical grade PUR 1020 UHMPE). The patella is available in five diameters, 26mm, 29mm, 32mm, 35mm and 38mm, which permit optimal bone coverage and surgical options.
The provided text describes a 510(k) premarket notification for the "PROLIXUS™ TOTAL KNEE SYSTEM". This document focuses on demonstrating substantial equivalence to legally marketed predicate devices, primarily through bench testing comparing the new device's mechanical properties, materials, and design to established standards and predicate devices.
Here's an analysis of the acceptance criteria and study information:
1. Table of Acceptance Criteria and Reported Device Performance
| Test | Acceptance Criteria (Implicit from ISO/Standard) | Reported Device Performance |
|---|---|---|
| Fatigue Test (Tibial Base Plate) | ISO 21536 suggested minimum fatigue strength (10 million load cycles at 900 N without failure) | Five tibial trays passed 10 million load cycles at 900 N without failure. Max run-out bending moment of 22.5 Nm. |
| Knee Constraint Test (Anterior-Posterior) | Implied to be comparable to predicate devices and within expected physiological ranges for stability. | 0° flexion: Mean anterior load -348 N (StdDev 9), posterior load 149 N (StdDev 4). |
| 15° flexion: Mean anterior load -348 N (StdDev 12), posterior load 147 N (StdDev 2). | ||
| 90° flexion: Mean anterior load -349 N (StdDev 3), posterior load 154 N (StdDev 4). | ||
| 135° flexion: Mean anterior load -331 N (StdDev 5), posterior load 152 N (StdDev 4). | ||
| Knee Constraint Test (Medial-Lateral) | Implied to be comparable to predicate devices and within expected physiological ranges for stability. | 0° flexion: Mean lateral load -396 N (StdDev 3), medial load 387 N (StdDev 6). |
| 15° flexion: Mean lateral load -385 N (StdDev 7), medial load 383 N (StdDev 3). | ||
| 90° flexion: Mean lateral load -415 N (StdDev 3), medial load 365 N (StdDev 3). | ||
| 135° flexion: Mean lateral load -370 N (StdDev 21), medial load 413 N (StdDev 5). | ||
| Knee Constraint Test (Internal-External Rotation) | Implied to be comparable to predicate devices and within expected physiological ranges for stability. | 0° flexion: Mean external torque -5.7 Nm (StdDev 0.4), internal torque 5.8 Nm (StdDev 0.2). |
| 15° flexion: Mean external torque -6.2 Nm (StdDev 0.3), internal torque 5.8 Nm (StdDev 0.1). | ||
| 90° flexion: Mean external torque -5.4 Nm (StdDev 0.1), internal torque 6.3 Nm (StdDev 0.1). | ||
| 135° flexion: Mean external torque -5.1 Nm (StdDev 0.4), internal torque 5.7 Nm (StdDev 0.1). | ||
| Knee Tibia and Inserter Component Interlock Strength (Disassembly - AP Loading) | Implied to be sufficient to prevent unintended disassembly during expected use. | Mean assembly load 138 N (StdDev 22). Mean disassembly load 1,459 N (StdDev 31). Failure mode: plastic deformation of snap-in locking mechanism. |
| Knee Tibia and Inserter Component Interlock Strength (Disassembly - ML Loading) | Implied to be sufficient to prevent unintended disassembly during expected use. | Withstood loads > 754 N (medial-lateral) and > 720 N (lateral-medial) with plastic deformation at load application point, no failure of interconnection mechanism. |
| Knee Tibia and Inserter Component Interlock Strength (Disassembly - Pull-off Loading) | Implied to be sufficient to prevent unintended disassembly during expected use. | Mean ultimate load 2,015 N (StdDev 187) without tibia tilt. |
| Knee Tibia and Inserter Component Interlock Strength (Assembly - AP Direction with tilt) | Implied to be within acceptable range for surgical assembly. | Mean assembly load of 132 N (StdDev 24) at 4.5 mm displacement. |
| Knee Tibia and Inserter Component Interlock Strength (Disassembly - AP and Lateral Direction) | Implied to be sufficient to prevent unintended disassembly during expected use. | Mean ultimate disassembly load of 804 N (StdDev 70). |
| Knee Femoral and Tibial Insert Contact Area/Pressure Distribution | Contact stresses and total contact areas fall within the common range of predicate devices (from EndoLab database of 19 test series). | Contact stresses and total contact areas are within the common range of predicate devices. |
| Knee Femoral and Patella Contact Area/Pressure Distribution | Implied to be comparable to predicate devices and expected physiological performance. | Smallest total contact area: 20.44 mm² (SD 0.29 mm²) at 15° flexion. Largest total contact area: 86.87 mm² (SD 0.92 mm²) at 135° flexion. Smallest contact area above 20 MPa: 11.61 mm² (SD 0.50 mm²) at 15° flexion. Highest contact area above 20 MPa: 66.07 mm² (SD 1.35 mm²) at 135° flexion. |
| Femoral Component Surface Finish | Ra |
§ 888.3560 Knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis.
(a)
Identification. A knee joint patellofemorotibial polymer/metal/polymer semi-constrained cemented prosthesis is a device intended to be implanted to replace a knee joint. The device limits translation and rotation in one or more planes via the geometry of its articulating surfaces. It has no linkage across-the-joint. This generic type of device includes prostheses that have a femoral component made of alloys, such as cobalt-chromium-molybdenum, and a tibial component or components and a retropatellar resurfacing component made of ultra-high molecular weight polyethylene. This generic type of device is limited to those prostheses intended for use with bone cement (§ 888.3027).(b)
Classification. Class II.