Derivation of a Standardized Method to Identify the Anterior Compartment of the Lower Extremity Using Point-of-Care Ultrasonography

Introduction: Anterior compartment syndrome (ACS) of the lower extremity is a well-recognized surgical emergency. The anterior compartment is the most frequently missed of the four compartments during lower extremity fasciotomy. This study describes a novel approach that combines sonographic measurements and physical examination landmarks to accurately identify the anterior compartment. Materials and Methods: This study was conducted as a prospective anatomical study of 94 volunteers at a single institution. Physical exam and sonographic methods were utilized to derive measurements of the anterior compartment, followed by biometric and validation data. Results: Volunteers for the derivation and validation phases of study were similar regarding gender, height and weight, age, and BMI. The derivation set revealed the distance to the anterior compartment to be 2.77 cm (median 2.6 cm, range 1.5 - 5.4 cm) from the mid-axial line and resulted in identification of the anterior compartment 100% of the time (p < 0.001). Findings were reproducible in the internal validation set with 100% accuracy. Conclusion: The fascial planes of the anterior compartment can be identified with 100% accuracy when utilizing physical examination and sonographic methods. This can serve as a foundation for future studies evaluating ways to reduce of the number of missed anterior compartment fasciotomies in the setting of ACS.