Examkin

Question

Difficulty: MediumOrthopedic Surgery

A 22-year-old collegiate athlete is brought to the emergency department immediately after sustaining a severe hyperextension injury to his left leg during a rugby match. He is in agonizing pain. On physical examination, there is a gross step-off deformity at the left knee joint. The left foot is cold and pale. The dorsalis pedis and posterior tibial pulses are absent on the left side but are robust on the right. Capillary refill time in the left toes is delayed at 5 seconds. Assuming evidence of arterial compromise persists throughout the initial evaluation, arrange the following management steps in the most appropriate sequential order.

  1. 1Perform emergent closed reduction of the tibiofemoral joint without prior imaging.
  2. 2Conduct a thorough post-reduction neurovascular examination, including an ankle-brachial index (ABI).
  3. 3Obtain a computed tomography (CT) angiography of the affected lower extremity.
  4. 4Proceed with operative vascular exploration and surgical repair.

Answer

The correct sequential order is to first perform emergent closed reduction, followed by a post-reduction neurovascular assessment (including ABI), then obtain CT angiography, and finally proceed with operative vascular repair.
Knee dislocations (tibiofemoral dislocations) are high-energy injuries notorious for causing popliteal artery damage due to the artery's tethered anatomical course. When a patient presents with a dislocated knee and a pulseless, ischemic limb, the absolute first step is emergent bedside closed reduction. Delaying reduction for X-rays is contraindicated because it prolongs limb ischemia. After reduction, the physician must reassess the vascular status with an ankle-brachial index (ABI). If the ABI is <0.9< 0.9 or pulses remain asymmetrical, CT angiography is indicated to localize the vascular injury. Finally, the patient is taken to the operating room for definitive vascular exploration and repair.

Step-by-Step Solution

1
Identify the critical emergency in the clinical presentation.
The patient has a clinically obvious knee dislocation accompanied by hard signs of vascular compromise (absent pulses, cold and pale foot, delayed capillary refill).
Recognizing limb-threatening ischemia dictates the urgency of the next interventions.
2
Determine the immediate intervention to restore perfusion.
Select emergent closed reduction without waiting for plain radiographs.
The popliteal artery is tightly tethered across the knee joint; prolonged dislocation causes traction and ischemia. Immediate reduction is required to potentially restore blood flow.
3
Determine the next step after the limb is anatomically realigned.
Select post-reduction neurovascular examination and measurement of the ankle-brachial index (ABI).
Vascular status often changes after reduction. It is mandatory to document whether perfusion has returned or if occult injury persists.
4
Determine the appropriate diagnostic test for persistent ischemia.
Select computed tomography (CT) angiography of the lower extremity.
Since the premise states vascular compromise persists, advanced imaging is necessary to map the presumed popliteal artery injury.
5
Identify the definitive management.
Select operative vascular exploration and repair.
A mapped arterial injury causing limb ischemia requires surgical repair to salvage the leg.

Key Concept

In the setting of a joint dislocation with hard signs of vascular compromise, immediate closed reduction takes precedence over obtaining baseline imaging to minimize ischemic time.
Estimated Time:1m 30s
Rate this question

Topics

Orthopedic Surgery

More questions from this topic