MicroPort Orthopedics
Thanks for visiting MicroPort Orthopedics!
For the best viewing experience, please set your device to landscape mode.
Nav Target

aMP™ Knee System

aMP™ Knee System

aMP™ Knee System

17 Years of Clinical Success.
370,000 Cases Globally.
Addresses Patient Dissatisfaction.

The Medial-Pivot Knee is uniquely engineered to reproduce a healthy knee’s stability and motion. With a stable, pivoting medial side and a lateral side that rolls forward or backward throughout flexion, the eMP® Knee System is designed to feel and function like a natural knee.

    Flexion Stability

    Constant Sagittal Radius.
    Normal Femoral Geometry.
    Eases Ligament Balancing.

    Based on several cadaveric studies1, 2, the aMP™ femoral component incorporates a constant sagittal radius of curvature extending from full extension to 90° flexion. Reproducing natural femoral geometry, it restores normal tibiofemoral kinematics and Range of Motion (ROM). Equally significant, it facilitates high contact area and normal patellofemoral articulation. The constant femoral radius of curvature also maintains equal tension on ligaments in flexion and extension and eases ligament balancing.

      Anatomic Motion

      Replicates Human Anatomy.
      Unique Tibiofemoral Articulation.
      Inhibits Instability.

      By studying the anatomy of the normal human knee, it has been shown that the tibia pivots about the medial femoral articular surface in flexion.3-4 The unique tibiofemoral articulation of the aMP™ Knee System not only replicates this kinematic motion, but also inhibits the instability found in traditional total knees. By replicating the motion and stability of the normal knee, patient function and satisfaction are improved.

        Wear Limiting

        High-Functioning Design.
        Durable and Long Lasting.
        Lower Wear Rate.

        Along with the need for a high-functioning knee, patients also demand an implant that is durable and long lasting. The aMP™ Knee System exhibits a repeatable motion path that not only reproduces the kinematics of the natural knee, but resists the multi-directional motion often occurring in traditional knee replacements. When compared to published data, the ADVANCE® Medial-Pivot Knee System has been shown to have a lower wear rate than DePuy’s LCS® and PFC® Sigma™ Rotating Platform and Zimmer’s Gender Solutions® NexGen® CR, M/G® II and Natural Knee® II Knee Systems. 5-8


          1. Mancinelli, CA. The instanteneous axis of rotation of the human knee joint. Doctoral dissertation. The University of West Virginia, 1994.
          2. Elias, SG, Freeman, MAR, and Gokcay, EI. A correlative study of the geometry and anatomy of: 260, 1990.Clinical Orthopaedics and Related Researchthe distal femur. 
          3. Hollister, AM, Jatana, S, Singh, AK, Sullivan, WW, Lupichuk, AG. The axes of rotation of the 290:259, 1993.Clinical Orthopaedics and Related Research knee. 
          4. Mancinelli, CA. The instanteneous axis of rotation of the human knee joint. Doctoral dissertation. The University of West Virginia, 1994.
          5. McEwen HM. The influence of design, materials and kinematics on the in vitro wear of total knee replacements. J Biomech. 2005;38:357-65.
          6. Schwenke T. Difference in wear between load and displacement control tested total knee replacements. Wear. 2009;267:757-62.
          7. Haider H. Comparison between force-controlled and displacement-controlled in-vitro wear testing on a widely used TKR implant. ORS poster. 2002;27:1007.
          8. Muratoglu OK. Metrology to quantify wear and creep of polyethylene tibial knee inserts. Clin
            Orthop Relat Res. 2003;410:155-64.