Is a knee dislocation an emergency requiring immediate transport to a hospital?

Is Knee Dislocation an Emergency Requiring Immediate Transport?

Yes, knee dislocation is an absolute emergency requiring immediate splinting and rapid transport to a trauma center or emergency department due to the high risk of limb-threatening neurovascular compromise.

Why This Is a True Emergency

Knee dislocation represents a limb-threatening injury that demands urgent recognition and transport. The injury carries significant risks of severe arterial, venous, and neurologic compromise that can result in limb loss if not managed expeditiously 1.

Classification as Time-Sensitive Extremity Injury

According to the National Expert Panel on Field Triage, knee dislocations fall under the category of "time-sensitive extremity injury," which specifically includes open fractures or fractures with neurovascular compromise 2. This classification mandates contact with medical control and consideration for transport to a trauma center 2.

The 2012 field triage guidelines explicitly identify injuries to extremities proximal to the knee as requiring transport to a trauma center when there is evidence of neurovascular compromise 2. Knee dislocations inherently involve structures at this critical anatomic level.

Critical Neurovascular Risks

Popliteal Artery Injury

• Popliteal artery damage is a well-documented complication requiring urgent surgical repair 3, 4
• The risk of arterial compromise makes this injury potentially limb-threatening if transport is delayed 1
• Neurovascular lesions occur in approximately 17.5% of knee dislocations 5

Nerve Injury

• Common peroneal nerve injury is frequently associated with knee dislocations 3, 4
• One case series documented peroneal nerve palsy in 25% of patients 4
• Deficits in peripheral perfusion, sensory function, and motor function are negative predictive factors for clinical outcomes 5

Immediate Field Management Protocol

On-Scene Actions

1. Rapid assessment of neurovascular status - Check for peripheral pulses, sensory function, and motor function immediately 1, 5
2. Splint the knee in position found - Immobilize without attempting field reduction 1
3. Minimize scene time - Target on-scene time should not exceed 15-20 minutes 2, 6
4. Provide immediate transport to an emergency department or trauma center 1

Transport Destination

Transport to a trauma center is strongly recommended based on the field triage guidelines that classify time-sensitive extremity injuries as requiring specialized trauma care 2. If the closest appropriate facility is not a designated trauma center, transport to the nearest emergency department capable of vascular surgery and orthopedic intervention 2.

Common Diagnostic Pitfall

Spontaneous reduction makes diagnosis more difficult 1. Many knee dislocations reduce spontaneously before EMS arrival, and the examiner must maintain high suspicion for knee dislocation in patients presenting with globally unstable knees even when the joint appears anatomically aligned 1. The presence of multiligamentous knee injury on examination should trigger the same emergency transport protocol 3, 5.

Why Delayed Transport Is Dangerous

• Prompt diagnosis and reduction are essential to reduce the risk of neurovascular complications 4
• The injury can be life-changing and potentially limb-threatening 3
• Close monitoring for persistent neurovascular compromise is required, which can only be provided in an emergency department setting 5
• Lack of peripheral perfusion and insufficient sensory/motor function are independent risk factors for poor outcomes 5

Special Consideration: Low-Energy Mechanisms

Do not be falsely reassured by low-energy mechanisms of injury. Recent case series demonstrate that morbidly obese patients can sustain knee dislocations from simple falls from standing height 4. These injuries carry the same neurovascular risks as high-velocity trauma and require the same urgent transport 4.