Transverse Crural Septum

septum intermusculare crurale transversum

The transverse crural septum separates the deep posterior compartment from the superficial posterior compartment of the leg, creating the fascial boundary between the flexor group and the gastrocnemius-soleus group.

Region: Lower Leg

Biomechanics

Function & Actions

Provides the compartmental separation between the deep flexors and the superficial plantarflexors of the leg, maintains compartment pressure independently in each group, and is the septum released when performing the deep posterior fasciotomy in four-compartment leg release.

Clinical Relevance

Clinical Notes

The transverse septum must be specifically identified and divided in deep posterior compartment release — failure to release it (while releasing only the overlying superficial posterior fascia) leaves the deep flexors under tension and is the most common cause of incomplete leg fasciotomy.

Pathology

Common Injuries & Conditions

Transverse Septum Release in Deep Posterior Fasciotomy

The transverse crural septum must be identified and divided in addition to the superficial posterior fascia to adequately decompress the deep posterior compartment in four-compartment leg fasciotomy.