Walking with a Posterior Cruciate Ligament Injury: A Musculoskeletal Model Study.

Area of Science:

• Biomechanics
• Orthopedics
• Computational modeling

Background:

• Posterior Cruciate Ligament (PCL) injuries alter knee joint kinematics and internal load distribution.
• Current understanding of PCL injury biomechanics and compensatory mechanisms remains incomplete.

Purpose of the Study:

• To analyze internal load redistribution among knee ligaments following PCL injury.
• To investigate hamstring muscle activation as a potential compensatory strategy for PCL deficiency.

Main Methods:

• A musculoskeletal knee model simulated progressive PCL injury by reducing ligament stiffness.
• Dynamic walking simulations analyzed altered hamstring forces in a PCL-deficient model.
• Ligament tension, tibiofemoral contact forces, and knee kinematics were quantified.

Main Results:

• The Medial Collateral Ligament (MCL) and Lateral Collateral Ligament (LCL) became primary stabilizers against posterior tibial translation in simulated PCL injury.
• Tibiofemoral contact forces increased in the PCL-injured model.
• Decreased hamstring force reduced tibial posterior translation, compensatory ligament tension, and tibiofemoral contact forces.

Conclusions:

• The MCL and LCL play a crucial role in stabilizing knees with PCL deficiency.
• Modulating hamstring activity may mitigate adverse biomechanical consequences of PCL injury.
• This computational model offers a tool for non-invasive assessment of load redistribution in PCL injuries, aiding clinical management and prevention of degeneration.