A 36 year old male presents with left lower extremity pain after a motor vehicle vs pedestrian accident. The patient was crossing a crosswalk when a car hit him at low speed. On exam, there is an obvious deformity with significant swelling and tenderness of the left lower leg. What type of fracture pattern is present and what delayed surgical emergency can potentially occur from this injury?
Answer: Comminuted displaced fractures of distal tibia and fibula – high risk for development of Acute Compartment Syndrome
- After a fracture, there can be extravasation of blood with increased tissue swelling and venous flow impairment within the fascial compartments. The build up in pressure causes circulatory compromise, neurologic damage, and muscle necrosis.
- The most common site of compartment syndrome is in the lower extremities at the tibia and fibula with a majority of cases occurring in the anterior compartment. Acute compartment syndrome can occur within a few hours of inciting trauma and can present up to 48 hours after.
- Patient’s typically feel pain out of proportion to exam with a tense “wood-like” compartment. Alarming symptoms include:
- Pain with passive or active stretching (most sensitive exam finding)
- Active contraction against resistance
- Direct pressure over the compartments
- Exam findings can be sufficient to make the diagnosis in the correct setting of an inciting event along with alarming symptoms.
- Using intracompartmental pressures alone as a guide, <30 mmHg would not require intervention whereas pressure >45 mmHg requires decompression.
- Obtaining the “delta pressure” between the direct compartment pressure and diastolic pressure, a difference <30 mmHg should warrant fasciotomy.
- Rapid diagnosis is key as within 3-4 hours in the muscle there can be reversible change and after 8 hours there is irreversible muscle damage; in the nerve, as soon as within 2 hours patients can have loss of nerve conduction and within 8 hours there is irreversible damage.
- Immediately remove restrictive casts or dressings and place affected limbs at the level of the heart.
- Surgical fasciotomy to reduce compartment pressure in a timely fashion.
- These wounds post operatively are left open for a second operating room look within 48-72 hours for wound closure.
- If delay in treatment, patient’s can have functional impairment including permanent neuropathy and contractures.
Tintinalli’s Emergency Medicine (9th ed). Mayersak, R. J. McGraw Hill, 2018. Chapter 267 and 278. Page 1782, 1876-1879
Torlincasi AM, Lopez RA, Waseem M. Acute Compartment Syndrome. [Updated 2023 Jan 16]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK448124/