Does meniscus removal affect ACL-deficient knee laxity? An in vivo study

Area of Science:

• Orthopedic Surgery
• Biomechanics
• Sports Medicine

Background:

• Anterior cruciate ligament (ACL) deficiency compromises knee joint stability.
• Meniscal tears are common in ACL-deficient knees and can further affect joint mechanics.
• Understanding the impact of meniscectomy on knee kinematics is crucial for treatment strategies.

Purpose of the Study:

• To investigate the in vivo biomechanical effects of different meniscectomy types on ACL-deficient knees.
• To quantify changes in knee joint kinematics following subtotal versus partial meniscectomy.
• To compare these effects against a control group with isolated ACL rupture.

Main Methods:

• A cohort of 56 patients with ACL deficiency and medial meniscus tears were analyzed using computer-assisted navigation.
• Patients underwent biomechanical testing, including Lachman, drawer, rotation, varus/valgus, and pivot-shift tests.
• Groups included subtotal meniscectomy (bucket-handle tear), partial meniscectomy (posterior horn tear), and a control group with isolated ACL rupture.

Main Results:

• Significant differences in anterior tibial translation were observed at 30 and 90 degrees between meniscectomy groups and the control group.
• No significant differences in pivot-shift test parameters (AREA, POSTERIOR ACC) were found among the groups.
• Statistically significant differences were identified in the anterior displacement during the pivot-shift test across the three groups.

Conclusions:

• Meniscal defects substantially influence the kinematics of ACL-deficient knees.
• These defects affect anterior tibial translation during both static and dynamic loading conditions.
• The type of meniscectomy may play a role in the resulting knee joint instability.