Acute Management of Traumatic Knee Dislocations for the Generalist

Abstract

Acute knee dislocations are an uncommon injury that can result in profound consequences if not recognized and managed appropriately on presentation. Patients presenting with knee pain in the setting of high- or low-energy trauma may have sustained a knee dislocation that spontaneously reduced. Prompt reduction of the dislocated knee and serial neurovascular examinations are paramount. Damage to the popliteal artery is a common associated injury that can be diagnosed on physical examination using ankle brachial indices (ABIs), CT angiography, or standard angiography. After reduction, patients with a normal pulse examination and an ABI ≥0.9 may be observed, with serial examination performed to document vascular status and monitor for compartment syndrome. Patients with asymmetric pulses or an ABI <0.9 in the presence of pulses may be treated urgently depending on the results of additional vascular imaging, and patients with absent pulses and clear signs of vascular compromise should be treated emergently. Some knee dislocations are not reducible and should be taken emergently to the operating room for an open reduction. Persistent joint subluxation or severe soft-tissue injuries after reduction require temporary external fixation before definitive repair or reconstruction of ligaments is performed.