Algorithm of Stannard et al for Performing Arteriography of the Lower Extremity Following Knee Dislocation

Patient selection: traumatic dislocation of the knee, usually following a high speed impact

Pathophysiology:

(1) The popliteal artery is held in close approximation to the femur behind the knee.

(2) Collateral circulation to the distal lower extremity is often insufficient.

Criteria for performing arteriography:

(1) history of an abnormal physical examination during the prehospital evaluation

(2) abnormal physical examination on presentation to the ED

(3) development of an abnormal physical examination while monitoring the extremity every 2-4 hours for the next 48 hours (12 to 24 evaluations)

Abnormal physical examination:

(1) expanding hematoma about the knee

(2) asymmetry in dorsalis pedis and/or posterior tibial arterial pulses

(3) asymmetry in color between the 2 lower extremities

(4) asymmetry in temperature between the 2 lower extremities

where:

• The description assumed dislocation of one knee. If both knees were dislocated, then deterioration in pulse or change in color or temperature over time could be used.

The authors noted that patients with knee dislocation type IV (KD-IV, with tears of both cruciate ligaments and both posteromedial and posterolateral ligaments) should be monitored more carefully.