Range of motion in total knee arthroplasty. A computer analysis

Area of Science:

• Orthopedic biomechanics
• Computational modeling in joint replacement
• Surgical simulation and optimization

Background:

• Accurate biomechanical modeling is crucial for improving total knee replacement (TKR) outcomes.
• Understanding the interplay between prosthetic design and knee joint kinematics is essential for surgical success.

Purpose of the Study:

• To create a validated 3D computer model of the knee for simulating TKR.
• To evaluate the impact of prosthetic component design and surgical placement on knee flexion and joint mechanics.

Main Methods:

• Development of a 3D knee model using sectional and coordinate data from anatomical specimens.
• Simulation of prosthetic component design and surgical placement within the computer model.
• Analysis of factors influencing maximum flexion, including ligament tension and component positioning.

Main Results:

• The 3D model accurately replicated known knee biomechanics regarding contact points and ligament lengths.
• Posterior cruciate ligament tension was the primary determinant of maximum knee flexion.
• Posterior tibial component tilt significantly increased knee motion, while anterior tilt decreased it.

Conclusions:

• Tibial component tilt in the sagittal plane is a critical surgical variable influencing TKR range of motion.
• Model-driven insights can inform the selection of total knee systems, instrument design, and surgical techniques.
• Optimizing component positioning based on biomechanical principles can enhance TKR functional outcomes.