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Difficulty: MediumOrthopedic Surgery

A 22-year-old male is brought to the emergency department after a high-speed motorcycle collision. He complains of severe right leg pain. On physical examination, his right knee is grossly deformed with a prominent medial femoral condyle. The patient's right foot is cold and pale, and the dorsalis pedis and posterior tibial pulses are not palpable. Capillary refill is delayed. Arrange the following management steps in the most appropriate chronological order for this patient, assuming that an arterial injury is present and requires definitive treatment.

  1. 1Perform immediate bedside closed reduction of the knee
  2. 2Measure the ankle-brachial index (ABI)
  3. 3Obtain a computed tomography angiography (CTA) of the lower extremity
  4. 4Perform operative vascular exploration and repair
  5. 5Perform elective multi-ligamentous knee reconstruction

Answer

The correct sequence is: immediate bedside closed reduction, followed by ABI measurement, CTA of the lower extremity, operative vascular repair, and finally elective multi-ligamentous reconstruction.
In the setting of a traumatic knee dislocation with absent distal pulses (a 'hard sign' of vascular injury), the immediate priority is restoring perfusion to the limb. This is accomplished by immediate bedside closed reduction of the knee, which often relieves kinking of the popliteal artery. This must be done prior to any radiographic evaluation to minimize warm ischemia time. Following reduction, vascular status must be objectively assessed. Even if pulses seem to return, an Ankle-Brachial Index (ABI) is measured to screen for occult injury. If the ABI is <0.9 or if pulses remain asymmetric or absent, Computed Tomography Angiography (CTA) is indicated to identify the exact location and nature of the vascular injury (e.g., intimal flap, transection). Once identified, urgent operative vascular repair is necessary. Finally, after the limb is successfully revascularized and soft tissues have healed over several weeks, elective multi-ligamentous reconstruction is performed to restore joint stability.

Step-by-Step Solution

1
Identify the ischemic limb with a dislocated joint.
Recognition of acute limb-threatening vascular compromise.
Guides the decision to bypass initial imaging and proceed directly to emergency intervention.
2
Perform immediate closed reduction.
Restoration of gross anatomical alignment.
Relieves mechanical compression or kinking of the popliteal artery, often restoring initial blood flow.
3
Assess post-reduction perfusion with ABI.
Objective measurement of arterial flow.
Screens for an occult intimal tear or persistent arterial occlusion that may not be obvious on physical exam.
4
Obtain CTA of the lower extremity.
Definitive localization and characterization of the arterial injury.
Provides a precise anatomical roadmap for the vascular surgeon.
5
Perform operative vascular repair.
Restoration of definitive limb perfusion.
Prevents ischemic necrosis, compartment syndrome, and amputation.
6
Perform delayed ligamentous repair.
Restoration of knee joint stability.
Performed electively after vascular integrity is assured and soft tissue inflammation has subsided to minimize surgical morbidity.

Key Concept

Chronological management of acute tibiofemoral dislocation with vascular compromise
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Topics

Orthopedic Surgery

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