The compartments of the foot: a 3-tesla magnetic resonance imaging study with clinical correlates for needle pressure testing.

Background: Reliable measurement of subfascial pressures represents an essential part of compartment syndrome management. To date, there is neither consensus on the number or location of foot compartments, nor a standardized protocol for needle placement. The purpose of this study was to devise a new system using 3-Tesla MRI that assesses the number and location of these compartments.

Methods: To document the specific location of foot compartments, high resolution 3-Tesla MRI (General Electric, Milwaukee, WI) was coupled with a dedicated transmit-receive high signal-to-noise foot/ankle coil (IGC-Medical Advances, Milwaukee, WI). Individual compartments were highlighted and mapped to T1-weighted MRI. Three-dimensional image analysis allowed standardized needle placement recommendations.

Results: Six feet from healthy volunteers were imaged. From these, ten compartments were described: (1) medial, (2) central superficial, (3) central deep (adductor), (4) lateral, (5-8) interossei, (9) calcaneal, and (10) skin. Optimal needle placement and depth were identified.

Conclusions: The proposed system allowed us to assess the number and location of foot compartments. Computer image analysis enabled us to define exact points for needle insertion and depth of penetration for accurate pressure monitoring.