Alteration in ACL loading after total and partial medial meniscectomy

Area of Science:

• Biomechanics
• Orthopedic Surgery
• Biomedical Engineering

Background:

• Anterior cruciate ligament (ACL) injuries are common in sports and can result from daily activities due to tissue degeneration or prior knee surgery like meniscectomy.
• Existing research often focuses on impact injuries or the effects of ACL injury on the meniscus, not vice versa.

Purpose of the Study:

• To investigate the biomechanical effects of varying degrees of medial meniscectomy on the intact ACL under moderate creep loading conditions.
• To analyze changes in knee laxity, ACL stress, and joint mechanics following medial meniscal resection.

Main Methods:

• Utilized a poromechanical finite element analysis of a knee model.
• Simulated four clinical scenarios: 25%, 50%, 75%, and total medial meniscectomy, comparing them to an intact knee model.
• Applied moderate creep loadings to assess mechanical responses over time.

Main Results:

• Medial meniscectomy, at varying extents, increased knee laxity and peak tensile stress in the ACL.
• ACL stress initially increased within the first few minutes of creep before reaching equilibrium.
• Meniscectomy accelerated ACL stress reduction during creep, increased tibial cartilage loading, elevated contact pressure, and shifted the contact area posteriorly.

Conclusions:

• Medial meniscectomy significantly impacts ACL mechanics, potentially increasing injury risk and altering joint mechanobiology during normal daily activities.
• Findings highlight the importance of the meniscus in maintaining knee joint stability and protecting the ACL.
• This study provides insights into the biomechanical consequences of meniscectomy on ACL integrity during sustained, moderate loading.