Review Question - QID 2135

Figures A-D are T2 MRI images that shows a grade III medial collateral ligament (MCL) tear with an associated ACL tear. The physical examination test most sensitive for detecting this combination injury would be the anterior drawer test with the tibia in external rotation.

Grade III valgus knee injuries commonly cause combined MCL and ACL ligament injury. The anterior drawer test with tibia in external rotation is used to detect anteromedial rotatory instability (indicating combined ACL and MCL injury), but may also include posteromedial structures (i.e., posteromedial capsule, medial meniscus). With this combined ACL and MCL injury, anterior drawer laxity in ER will be greater than laxity in neutral and internal rotation.

Fetto et al reviewed MCL injuries of the knee. They found ACL tears to be the most common secondary ligamentous injury associated with MCL injuries. This is particularly true in high-grade MCL tears. They suggest that both medial collateral advancement or reconstruction should be considered at the time of the ACL reconstruction, or vice versa.

Figure A shows a T2 MRI with grade III medial collateral ligament tear. Figure B,C,D are MRI sagittal views of the knee showing a complete ACL tear.

Incorrect Answers:
Answer A: Posterior drawer test is used to test for PCL ligament laxity
Answer B: Anterior drawer test in neutral is used to test for ACL ligament laxity.
Answer D: The dial test will look for posterolateral rotary instability of the knee indicative of injuries to the posteriolateral corner +/- PCL.
Answer E: McMurray test will examine for meniscal injury. These are commonly seen with MCL injuries.