Which maneuver is most accurate for detecting an anterior cruciate ligament tear?

Which maneuver is most accurate for detecting an anterior cruciate ligament tear?

• A. Lachman test
• B. Anterior drawer test
• C. Pivot-shift test
• D. Varus stress test

Answer: (A)

Assessing ACL integrity is best done with the Lachman maneuver because it isolates the ACL by placing the knee in a modest flexion (about 20–30 degrees) where the tibia is most dependent on the ACL for anterior restraint. With the femur stabilized, gently pulling the tibia forward reveals the amount of anterior translation and the quality of the end-feel. A marked translation with a soft or absent end-feel strongly suggests ACL rupture. This test is more sensitive and reliable than other maneuvers because it minimizes hamstring guarding and better isolates the ACL, making it the most accurate single clinical test for an ACL tear. The anterior drawer test, performed with the knee at 90 degrees, can be less reliable due to hamstring guarding and the influence of surrounding structures, and it doesn’t isolate the ACL as cleanly as the Lachman maneuver. The pivot-shift test assesses rotational instability and dynamic forward-lacking stability, which can be highly specific but is technique-dependent and less reliable in isolated injuries. The varus stress test evaluates the lateral structures, not the ACL.

Assessing ACL integrity is best done with the Lachman maneuver because it isolates the ACL by placing the knee in a modest flexion (about 20–30 degrees) where the tibia is most dependent on the ACL for anterior restraint. With the femur stabilized, gently pulling the tibia forward reveals the amount of anterior translation and the quality of the end-feel. A marked translation with a soft or absent end-feel strongly suggests ACL rupture. This test is more sensitive and reliable than other maneuvers because it minimizes hamstring guarding and better isolates the ACL, making it the most accurate single clinical test for an ACL tear.

The anterior drawer test, performed with the knee at 90 degrees, can be less reliable due to hamstring guarding and the influence of surrounding structures, and it doesn’t isolate the ACL as cleanly as the Lachman maneuver. The pivot-shift test assesses rotational instability and dynamic forward-lacking stability, which can be highly specific but is technique-dependent and less reliable in isolated injuries. The varus stress test evaluates the lateral structures, not the ACL.