Dynamically tensioned ACL functional knee braces reduce ACL and meniscal strain.

Area of Science:

• Orthopedic biomechanics
• Sports medicine
• Rehabilitation engineering

Background:

• The effectiveness of functional knee braces in reducing anterior cruciate ligament (ACL) and meniscal strain post-injury or reconstruction is not well-established.
• A novel dynamic knee tensioning brace system has been developed to provide active knee stabilization.
• The capacity of this new system to mitigate tissue strains requires investigation.

Purpose of the Study:

• To evaluate the ability of a dynamically tensioned brace to reduce strain in the ACL and meniscus during common rehabilitation activities.
• To assess the brace's efficacy in ACL-intact, ACL-deficient, and ACL-reconstructed knee conditions.

Main Methods:

• A hybrid in vivo/in silico/in vitro approach was employed.
• Seven cadaveric knee specimens were instrumented with custom braces and subjected to gait, double leg squat, and single leg squat simulations.
• Muscle forces and kinematics were captured via motion analysis, and medial meniscal and ACL strains were measured.

Main Results:

• The dynamic tensioning brace significantly reduced peak and average meniscal strain in ACL-deficient knees by 1.7% (P < 0.05).
• The brace also lowered meniscal strain in reconstructed knees by 1.1% and ACL strain in both ACL-intact (1.3%) and reconstructed knees (1.4%) (P < 0.05).

Conclusions:

• The study validates the use of dynamic tensioning braces for reducing meniscal strain in ACL-deficient knees, potentially decreasing the risk of secondary meniscal tears.
• The brace may offer prophylactic benefits for ACL injuries and aid in protecting ACL grafts after reconstruction.
• Findings provide valuable data for clinicians advising on functional brace utilization for knee instability.