As the tib/fib joint has its own synovial cavity, a knee effusion will not be seen
Mechanism: fall on the flexed knee with foot/ankle inversion
Hx: swelling, variable amount of lateral knee pain (anywhere from mild discomfort to inability to bear weight)
PE: Prominence of the fibular head, ankle motion exacerbates knee pain. no associated neurovascular issues
However with less common dislocations (posterior and superior) peroneal nerve injury may occur
Reduction: Place patient supine with knee flexed to 90 degrees. Ankle should be dorsiflexed and externally rotated.
REVERSE THE INJURY: Apply firm posteriorly directed pressure to the fibular head. May head an audible pop as fibular head reduces. Reassess collateral ligament function.
