In vitro assessment of prophylactic knee brace function.

Area of Science:

• Biomechanics
• Sports Medicine
• Orthopedic Engineering

Background:

• Knee ligament injuries are common in sports, particularly from direct lateral impacts.
• Prophylactic knee braces are used to prevent such injuries, but their effectiveness is debated.
• Understanding brace mechanics and material properties is crucial for optimizing knee protection.

Purpose of the Study:

• To evaluate the effectiveness of prophylactic knee braces in preventing knee ligament injuries.
• To determine how brace design and materials influence knee protection.
• To establish biomechanical standards for brace performance.

Main Methods:

• Preliminary biomechanical testing of cadaver limbs to understand knee restraint failure.
• Static and dynamic mechanical property analysis of six different prophylactic braces.
• Development and validation of an instrumented surrogate knee for controlled lateral impact testing.
• Evaluation of brace effectiveness using impact facilities with varied parameters (mass, velocity, flexion angle).

Main Results:

• Most tested prophylactic knee braces were biomechanically inadequate for protecting the medial collateral ligament (MCL) from direct lateral impact.
• Some braces showed preferential protection for the anterior cruciate ligament (ACL).
• All braces provided some benefit to the MCL and ACL, but performance fell below the established 1.5 Impact Safety Factor (ISF) standard.

Conclusions:

• The concept of prophylactic lateral knee bracing can be effective with improved designs.
• Current braces generally fall short of biomechanical standards for preventing direct lateral impact injuries.
• Further research, biomechanical validation, and clinical studies are recommended to advance prophylactic knee bracing technology.