Forces at the Anterior Meniscus Attachments Strongly Increase Under Dynamic Knee Joint Loading

Area of Science:

• Orthopedic biomechanics
• Knee joint mechanics
• Meniscal root anatomy and function

Background:

• Anterior meniscus roots are critical for knee stability, but loads on these structures under physiological conditions are poorly understood.
• Existing research often uses simplified loading models, potentially underestimating in vivo forces.

Purpose of the Study:

• To quantify anterior meniscus attachment forces during simulated physiological knee movements.
• To investigate the influence of muscle forces and meniscal damage on these forces.

Main Methods:

• Utilized a knee simulator to perform squat and jump landing simulations on cadaveric knees.
• Measured strains in anterior meniscus attachments and periphery under intact, torn, and post-meniscectomy conditions.
• Incorporated physiological muscle force simulation and in situ tensile testing.

Main Results:

• Physiological muscle force simulation significantly increased anterior meniscus attachment strains (up to 308%) and forces (max 140 N during jump landing).
• A longitudinal tear or total medial meniscectomy further amplified strains and forces during simulated drop jumps.
• Static loading tests underestimate actual forces experienced during dynamic movements.

Conclusions:

• Dynamic knee simulations with muscle forces provide a more accurate assessment of anterior meniscus attachment forces.
• Meniscal tears and meniscectomy substantially increase forces on anterior meniscus roots, highlighting the need for robust repair or replacement.
• Findings can inform the design of meniscal grafts and surgical repair techniques.