S. Mell (Chicago, US)
Rush University Medical Center Orthopaedic SurgeryPresenter Of 1 Presentation
P105 - An In-silico Method of Evaluating the Effect of Tibial Tubercle Osteotomy on Patellofemoral Cartilage Pressure
Abstract
Purpose
To generate a semi-automated computational framework for investigating changes in patellofemoral cartilage contact pressure and patellar tracking after AMZ TTO, using subject specific models, dynamic motions, and finite element analysis (FEA) for increased contact pressure accuracy.
Methods and Materials
MRI images from a single patient diagnosed with patellar instability were manually segmented using Mimics (Materialize, NV) into bone and cartilage for the patella and femur, as well as the tibia, quadriceps tendon, and patellar tendon for reference. FEA models were run using Abaqus/Standard 2019 (Dassault Systèmes). The baseline case was native anatomy. Five different surgical scenarios for AMZ TTO were modelled by varying the location of the attachments of the patellar tendon to the tibial tubercle with simulated osteotomy angle cuts of 15, 30, 45, and 60 degrees with translation of 15mm for all conditions. Change in maximum contact pressure on the patella as compared to native anatomy and change in contact path of the center of pressure on the patella and femur were compared for each scenario.
Results
Contact pressure was greatest for the native anatomy and occurred at 12° of flexion. Maximum contact pressure decreased for all AMZ TTO conditions (15°: 0.58; 30°: 0.86; 45°: 0.60; 60°: 0.62, normalized by native anatomy maximum contact pressure). The path of center of pressure changed subtly for the AMZ TTO conditions with increasing cut angle leading to a more medialized center of pressure at the maximum knee flexion angle and a more superior center of pressure as knee flexion increases during deep squat.
Conclusion
Under all AMZ TTO conditions tested, contact pressure was significantly reduced when compared to the native anatomy. Contact pressure location throughout flexion was similar for the AMZ TTO conditions, however differed from the native anatomy.
Presenter Of 1 Presentation
P105 - An In-silico Method of Evaluating the Effect of Tibial Tubercle Osteotomy on Patellofemoral Cartilage Pressure
Abstract
Purpose
To generate a semi-automated computational framework for investigating changes in patellofemoral cartilage contact pressure and patellar tracking after AMZ TTO, using subject specific models, dynamic motions, and finite element analysis (FEA) for increased contact pressure accuracy.
Methods and Materials
MRI images from a single patient diagnosed with patellar instability were manually segmented using Mimics (Materialize, NV) into bone and cartilage for the patella and femur, as well as the tibia, quadriceps tendon, and patellar tendon for reference. FEA models were run using Abaqus/Standard 2019 (Dassault Systèmes). The baseline case was native anatomy. Five different surgical scenarios for AMZ TTO were modelled by varying the location of the attachments of the patellar tendon to the tibial tubercle with simulated osteotomy angle cuts of 15, 30, 45, and 60 degrees with translation of 15mm for all conditions. Change in maximum contact pressure on the patella as compared to native anatomy and change in contact path of the center of pressure on the patella and femur were compared for each scenario.
Results
Contact pressure was greatest for the native anatomy and occurred at 12° of flexion. Maximum contact pressure decreased for all AMZ TTO conditions (15°: 0.58; 30°: 0.86; 45°: 0.60; 60°: 0.62, normalized by native anatomy maximum contact pressure). The path of center of pressure changed subtly for the AMZ TTO conditions with increasing cut angle leading to a more medialized center of pressure at the maximum knee flexion angle and a more superior center of pressure as knee flexion increases during deep squat.
Conclusion
Under all AMZ TTO conditions tested, contact pressure was significantly reduced when compared to the native anatomy. Contact pressure location throughout flexion was similar for the AMZ TTO conditions, however differed from the native anatomy.