Knee Dislocation (Emergency Management)

⚙️What This Procedure Involves

Emergency reduction: under sedation or general anaesthesia, the knee is reduced by applying longitudinal traction and reversing the direction of displacement. The knee is splinted in slight flexion. Vascular assessment: pedal pulses are checked, and Ankle-Brachial Pressure Index (ABPI) is measured. If pulses are absent or ABPI is less than 0.9, urgent CT angiography is performed. Vascular repair within six to eight hours if the artery is damaged. External fixation may be applied to maintain reduction. Definitive ligament reconstruction is typically delayed two to three weeks.

💡Why It May Be Recommended

Knee dislocation is an emergency because the popliteal artery is at risk — the artery is tethered behind the knee and tears in approximately 20–40% of dislocations. A delay of more than six to eight hours in restoring blood flow results in a high amputation rate.

⚖️Non-Operative Alternatives

There are no alternatives to emergency reduction. Definitive ligament reconstruction may be staged or, rarely, managed non-operatively with bracing in patients unfit for surgery.

📋Preparing for Surgery

This is an emergency. Reduction first. Vascular assessment immediately after. Splinting and serial neurovascular monitoring. MRI when the patient is stable to plan definitive ligament surgery.

✅Expected Benefits

Limb salvage when vascular injury is identified and treated promptly. Restoration of knee stability with staged ligament reconstruction. Most patients achieve a functional knee, though some degree of residual laxity is common.

⚠️Common Risks

• Vascular injuryCommon

  Popliteal artery damage in 20–40% of dislocations.

• Peroneal nerve palsyCommon

  Common peroneal nerve injury causing foot drop in approximately 25–35%.

• Knee stiffnessCommon

  Very common after multi-ligament injury. Arthrofibrosis in 10–20%.

• Residual instabilityCommon

  Some degree of persistent laxity despite reconstruction.

🔴Less Common but Serious Risks

• AmputationUncommon

  If vascular repair fails or is delayed beyond six to eight hours. Risk approximately 5–10%.

• Compartment syndromeUncommon

  From reperfusion injury after vascular repair.

• Chronic painUncommon

  Complex regional pain syndrome or chronic knee pain.

• Deep vein thrombosisCommon

  High risk with immobility.

💉Anaesthetic Considerations

Sedation or general anaesthesia for reduction. General anaesthesia for vascular repair and subsequent procedures.

🏃Recovery and Rehabilitation

Initial external fixation or hinged brace. Staged ligament reconstruction at two to three weeks. Prolonged rehabilitation over twelve to eighteen months. Return to sport at twelve to eighteen months. Some patients do not return to high-level sport.

📅Follow-Up

Serial vascular assessments in the first 48 hours. MRI for ligament assessment. Staged reconstruction at two to three weeks. Long-term rehabilitation.

❓Frequently Asked Questions