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Contact forces in several TKA designs during squatting: A numerical sensitivity analysis
Bernardo Innocenti1, Silvia Pianigiani, Luc Labey
1European Centre for Knee Research, Smith & Nephew, Technologielaan 11bis, 3300 Leuven, Belgium. bernardo.innocenti@smith-nephew.com
Journal of Biomechanics
|March 26, 2011
Summary
Patient anatomy and implant positioning significantly impact total knee arthroplasty (TKA) outcomes. Sensitivity analysis reveals patellar height and tibial component placement critically affect patellofemoral forces, while ligament alignment influences tibiofemoral forces.
Area of Science:
- Biomechanical Engineering
- Orthopedic Surgery
- Medical Device Design
Background:
- Total knee arthroplasty (TKA) is a common procedure, yet some patients experience persistent pain and functional limitations.
- Factors like implant design, surgical alignment, and patient-specific anatomy can influence TKA success.
Purpose of the Study:
- To perform a numerical sensitivity analysis on various TKA designs.
- To investigate how patient-related anatomical factors and component positioning affect patellofemoral (PF) and tibiofemoral (TF) contact forces in different TKA types.
Main Methods:
- Virtual implantation of four TKA types (fixed bearing, high flexion, mobile bearing, hinge) onto a single cadaver leg model.
- Simulation of a loaded squat from 0° to 120° to analyze knee kinematics.
- Sensitivity analysis of parameters including patellar position and tilt, tibial component position, collateral ligament locations, and patellar tendon length.
Main Results:
- Patellofemoral contact forces are highly sensitive to patellar height (up to 67% increase in patella-alta), anterior tibial component translation (up to 30%), and patellar component tilting (up to 29%).
- Tibiofemoral contact forces are most sensitive to the anterior displacement of medial collateral ligament insertion points (up to 48%).
Conclusions:
- Anatomical variations and surgical component placement are critical determinants of contact forces in TKA.
- Optimizing implant positioning and understanding patient anatomy are essential for improving TKA outcomes and reducing post-operative complications.
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