- Definition:
- medial plateau of the tibia rotating excessively forward & externally on femur as the joint opens on the medial side;
-
torn structures:
-
MCL;
-
posterior oblique ligament;
-
ACL;
-
medial meniscus tear;
- Exam:
-
anterior drawer test: (for anteromedial instability)
- tibia rotates anteriorly & externally as joint opens on the medial side;
-
rotation:
- positive drawer test in neutral tibial rotation;
- drawer test is accentuated in 30 deg of external rotation;
- drawer test is reduced w/ tibia in 15 deg of
Internal Rotation;
- Treatment:
- when anteromedial rotatory instability is present, reefing of posteromedial capsule is considered;
The role of incompetence of the anterior cruciate and lateral ligaments in anterolateral and anteromedial instability. A biomechanical study of cadaver knees.
Combined anterolateral-anteromedial rotatory instability of the knee. Norwood LA Jr. Hughston JC. COOR. (147):62-7, 1980 Mar-Apr.
Classification of knee ligament instabilities. Part I. The medial compartment and cruciate ligaments.
Acute anteromedial rotatory instability. Long-term results of surgical repair. Hughston JC. Barrett GR. JBJS - Am Vol 65(2):145-53, 1983 Feb.
Classification of ligament injuries: why an anterolateral laxity or anteromedial laxity is not a diagnostic entity.
Range of Motion and Quadriceps Muscle Power After Early Surgical Treatment of Acute Combined Anterior Cruciate and Grade-III Medial Collateral Ligament Injuries