A 29-year-old previously healthy man comes to the hospital with a right leg injury after a cycling accident. He reports pain in the lower leg and inability to bear weight. X-ray reveals right tibial and fibular shaft fractures. The patient undergoes closed reduction and immobilization of the fractures. Several hours later, he has increasingly severe pain in his right leg. Physical examination shows increased tension within the anterior compartment. Which of the following structures is most likely to be compromised by this patient's acute complication?

Question

A 29-year-old previously healthy man comes to the hospital with a right leg injury after a cycling accident.  He reports pain in the lower leg and inability to bear weight.  X-ray reveals right tibial and fibular shaft fractures.  The patient undergoes closed reduction and immobilization of the fractures.  Several hours later, he has increasingly severe pain in his right leg.  Physical examination shows increased tension within the anterior compartment.  Which of the following structures is most likely to be compromised by this patient's acute complication?

Quizplus · Accepted Answer

11ec160b_35e3_dea8_9249_f5b088b4ddf8_MD0001_00 The deep fascia of the leg, the fascial intermuscular septae, and the interosseous membrane divide the leg into 4 compartments (anterior, lateral, and superficial and deep posterior). The fascia is inelastic and limits outward expansion of the contracting muscles. If the pressure in a compartment increases, the circulation within it can become compromised, leading to severe pain and eventual tissue ischemia. This complication, acute compartment syndrome (ACS), can be due to long-bone fractures, crush injury, thermal injury, or nontraumatic causes (eg, bleeding disorders, vascular disease). Early diagnosis and surgical decompression (fasciotomy) of the involved compartments are necessary to prevent permanent and disabling injury (eg, myonecrosis, nerve damage, amputation). The most common site for ACS is the anterior compartment of the leg, which includes the foot extensor muscles, anterior tibial artery, and the deep peroneal (fibular) nerve. Injury to the deep peroneal nerve causes decreased sensation between the first and second toes, decreased dorsiflexion of the foot, foot drop, and claw foot. (Choice B) The great (long) saphenous vein starts in the dorsum of the foot and runs along the medial leg and anterior thigh before merging with the common femoral vein in the femoral triangle. It is outside the deep fascia and is not vulnerable to ACS. (Choice C) The peroneal veins accompany the peroneal artery and drain blood from the lateral compartment into the deep posterior compartment and eventually into the posterior tibial veins. (Choices D and F) The deep posterior compartment contains the posterior tibial artery, peroneal artery, and tibial nerve. ACS involving this compartment may cause decreased sensation in the plantar surface, decreased toe flexion, and pain with passive toe extension. (Choice E) The lateral compartment of the leg contains the superficial peroneal nerve and the proximal part of the deep peroneal nerve. ACS in this compartment can produce loss of sensation in the lower leg and dorsum of the foot as well as foot drop. Educational objective: Acute compartment syndrome (ACS) is caused by increased pressure within fascial compartments of the limbs, leading to impaired perfusion. ACS can cause severe pain, myonecrosis, and nerve injury. The anterior compartment of the leg, which contains the deep peroneal (fibular) nerve, is the most common site of ACS. __________ References: Acute lower-leg compartment syndrome. (http://www.ncbi.nlm.nih.gov/pubmed/23937740)

A 29-Year-Old Previously Healthy Man Comes to the Hospital with a Right