DePuy Recommendations for Side-Specific Implants in the Attune Knee System
DePuy requires the use of side-specific (left or right) implants for the Attune knee system, as the components are anatomically designed to match the specific geometry of left and right knees.
Anatomical Design Features of Attune System
The Attune knee system incorporates anatomical design features that necessitate side-specific implants:
- Asymmetric femoral component design that matches the natural anatomy of left and right knees
- Side-specific tibial components that accommodate the anatomical differences between left and right tibial plateaus
- Patellofemoral tracking system designed to match the natural Q-angle differences between left and right knees
Clinical Benefits of Side-Specific Implants
Research comparing the Attune system to previous designs demonstrates several advantages:
- Improved range of motion at 3 months postoperatively compared to the PFC Sigma system (p=0.049) 1
- Superior patient-reported outcomes with the Attune system compared to PFC Sigma in patients with both prostheses in opposite knees 2
- Significant improvement in WOMAC scores, Oxford Knee Scores, and SF-12 scores with the Attune system 2, 3
Technical Considerations
When using the Attune system:
- The side-specific design requires careful preoperative planning to ensure the correct implant (left or right) is available
- Intraoperative confirmation of correct side-specific component selection is essential before implantation
- Using the wrong side implant could lead to:
- Improper patellofemoral tracking
- Suboptimal kinematics
- Potential for increased wear and earlier failure
Potential Pitfalls
Surgeons should be aware of several important considerations:
- Mistakenly using the wrong side implant can lead to poor functional outcomes and potentially early revision
- The Attune system has a different posterior tibial slope angle than previous designs, which may increase the risk of posterior tibial cortex injury in patients with large preoperative posterior slope angles 4
- The cement-implant interface has been redesigned in newer versions (Attune S+) to provide stronger fixation compared to the original Attune design 5
Summary
The anatomical design of the Attune knee system requires strict adherence to side-specific implant selection. Using the correct side-specific implant is essential for achieving optimal functional outcomes and reducing the risk of complications or early failure.