If Lachman's Test reveals a 5-10 mm movement of the knee, what grade is this?

Lachman's Test is a clinical assessment used to evaluate the integrity of the anterior cruciate ligament (ACL) in the knee. This test assesses the amount of anterior displacement of the tibia in relation to the femur. The grading system for the results of Lachman's Test is based on the amount of tibial translation.

A movement of 5-10 mm indicates that there is a moderate degree of instability present in the knee joint, which aligns with a 2+ grade on the Lachman scale. This means that while there is a noticeable increase in movement compared to a healthy knee, it is not maximal instability, which would be classified as 3+ or higher.

A 2+ grade suggests that there is significant enough compromise of the ACL that anterior translation is observable and that this degree of movement corresponds to a partial tear or moderate sprain of the ligament.

In summary, the 5-10 mm of movement observed in Lachman's Test signifies a 2+ grading due to the moderate degree of instability it represents, which is consistent with a notable but not complete compromise of the ACL.