Biomechanical and Anatomical Effects of an External Rotational Torque Applied to the Knee: A Cadaveric Study

Rick Csintalan, Amirhesam Ehsan, Michell McGarry, Donald Fithian and Thay Lee

External rotation is one of the mechanisms that may occur during a twisting injury to the knee.  The aim of this study was to examine the effect of rotational forces on passive stabilising structures of the knee.  Six cadaveric knees were subject to external rotation forces, the specimens were then dissected to identify the injured structures.  Dissection showed that all posterior cruciate ligaments were intact; all medial collateral ligaments and anterior cruciate ligaments were either partially or completely torn.  The lateral collateral ligaments were torn in all specimens.  The authors concluded that external rotation increased joint laxity and dissection revealed a consistent pattern of injury to the ACL, MCL and LCL.  The authors added that as isolated ligament tears are rare recognising these combined ligamentous injuries early could improve outcomes.

The American Journal of Sports Medicine 34:1623-1629 (2006)

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