Quantifying the Mechanical Effects of Knee Bracing and Predicting their Ability to Prevent Ligamentous Injury

University Of Pittsburgh At Pittsburgh, Pittsburgh PA

Investigators

Abstract

Project Summary/Abstract The medial collateral ligament (MCL) is the most injured structure in the knee especially during sports such as football, soccer, rugby, ice hockey, and wrestling. The rate of injury in the National Football League alone was 0.155 MCL injuries per team-game, which was three times more common than anterior cruciate ligament (ACL) injuries. However, an additional 400,000 ACL injuries occur each year resulting in an economic impact of $25.3 billion, where approximately 44-67% of cases also involve MCL injuries. Prophylactic knee braces are often proactively prescribed to prevent ligamentous injury, or to reduce joint loading in isolated MCL injury, isolated ACL injury, or combined ligamentous injuries. Knee braces may also be prescribed following ligamentous reconstruction to reduce loading on the healing graft and provide additional stability in response to rotational and translational loading. Braces may provide stability by increasing the stiffness of the knee in response to rotatory and translational loads, however, the American Academy of Orthopaedic Surgeons does not recommend prophylactic knee braces given the quality of past and recent evidence is low and conflicting. The financial cost of bracing is also high, necessitating evidence of injury reduction to rationalize utilization. A multimethodological approach with cadaveric specimens will be utilized to isolate the mechanistic effects of knee braces. A 6 DoF robotic testing system will be used to quantify the effects of knee bracing in native, MCL deficient, and MCL + ACL deficient knees in response to external loading conditions. Computational models will then be developed and validated using specimen specific geometry and experimental data to predict if knee braces prevent ligamentous injury. The project will address three specific aims: 1) Determine the effects of prophylactic bracing on tibiofemoral kinematics in response to external loading conditions for native and injured knees; 2) Quantify the stiffness of the knee and knee + brace complexes in native and injured knees at varying flexion angles; 3) Develop and validate computational models to perform failure analyses to determine if braces prevent failure of the MCL and ACL compared to the native knee during high impact loading. The fellowship training plan was designed based on the applicant’s career goal of becoming an independent researcher studying musculoskeletal and injury biomechanics, with focus in solid mechanics training. Specifically, training includes characterizing the function of biological structures (robotic testing and failure analyses), leadership and mentoring skills, developing collaborations, and grant writing. Mentorship from Dr. Debski (Sponsor) and Dr. Fagerström (Co-Sponsor, Chalmers University of Technology) will aid the fellow in achieving their career goal through training in solid mechanics and provides a unique opportunity for international and industrial (ēlizur, see letter of support) collaboration broadening the applicant’s horizons. Annual one- month visits to Sweden will also expose the applicant to the Division of Vehicle Safety specializing in computational models for crashworthiness predictions.