The Anterior Cruciate Ligament (ACL) is the most commonly injured ligament in the body. The overall goal of this project is to develop patient-specific computational pediatric knee models that can accurately predict the in vivo biomechanical environment of the ACL. The foundation of this research is broken down into three specific parts:​ 1) model construction, 2) model validation, and 3) model application.

Specific Aim #1 developed anatomically accurate specimen-specific finite element representations of pediatric tibiofemoral joints. The models were able to demonstrate the ability for the Open Knee cruciate stereolithography (stl) files to be three-dimensional scaled to create subject-specific ligaments that accurately reflect the in vivo ligament size and orientations.

In Specific Aim #2, clinical, historical in vivo data were utilized to validate the model’s accuracy in predicting anterior tibial translation when subject to the Lachman and pivot shift tests. The FEBio models were able to predict anterior tibial translations that were not statistically different than the historical control data (p>0.05).

Finally, Specific Aim #3 analyzed at-risk ACL orientations and loading patterns. When subject to the Lachman and pivot shift tests, the ACL 11 o’clock malposition models predicted anterior tibial translations that were not statistically different from the in vivo data (p>0.05). The 11 o’clock finite element knee models resulted in greater anterior displacement than those with the native (approximately 10 o’clock) ACL position. The difference in anterior tibial translation between the native and 11 o’clock ACL orientations was statistically significant (p<0.05). Furthermore, at-risk low and high impact sporting loading conditions were analyzed. The high impact side cutting maneuver resulted in a 102% (ACL) and 47% (MCL) increase in ligament displacement compared to the low impact baseball swing simulation for each ligament (p< 0.05).

Ultimately, the information obtained from this investigation allows for a unique and in-depth analysis of the ACL. As such, the project provides the opportunities to obtain biomechanical analyses that are difficult to investigate through in vivo experimentation and create a solid foundation for future pediatric tibiofemoral joint computational modeling