Kinematic Patterns of Different Loading Profiles Before and After Total Knee Arthroplasty: A Cadaveric Study

Area of Science:

• Orthopedic surgery
• Biomechanics
• Biomedical engineering

Background:

• Total knee arthroplasty (TKA) aims to restore knee function.
• Understanding knee kinematics during various activities is crucial for selecting appropriate TKA designs.
• Assessing the correlation between passive and active knee motion can inform surgical choices.

Purpose of the Study:

• To compare anterior-posterior (AP) range of motion during simulated passive flexion and stair ascent in TKA patients.
• To evaluate differences in AP translation between TKA designs with and without a post-cam mechanism.
• To determine if TKA designs can replicate native knee AP translation during different activities.

Main Methods:

• Utilized a six-degrees-of-freedom joint motion simulator to analyze knee kinematics.
• Compared passive flexion and stair ascent activities under various conditions.
• Evaluated both cruciate-retaining/cruciate-substituting (CR/CS) and posterior-stabilized (PS) TKA designs.

Main Results:

• Neither TKA design demonstrated superiority in restoring mean native AP translation.
• Both CR/CS and PS TKA designs showed potential for restoring individual native kinematic patterns.
• Passive and complex loading scenarios yielded similar TKA design choices for replicating native knee behavior.

Conclusions:

• TKA design selection should consider individual kinematic patterns over mean restoration.
• Both CR/CS and PS TKA designs may effectively restore native knee kinematics.
• Kinematic patterns differ between passive and active loading but guide similar implant choices.