Technique

Positioning and preparation: Supine positioning. Tourniquet not inflated.

Anterior and lateral compartments: Longitudinal incision is marked mid-way between the fibula and the tibial crest. This should be extended longitudinally from the tibial tuberosity to 2cm above the lateral malleolus.

During sharp dissection of the subcutaneous layer, the superficial peroneal nerve should be identified 10-12cm proximal to the tip of the lateral malleolus.

Once the fascia is well-cleared, identify the fibres of the intermuscular septum between the anterior and lateral compartments. If in doubt, a short transverse fascial incision can be performed to confirm the location. Once the boundary between the anterior and lateral compartments has been identified, perform a longitudinal fasciotomy to decompress the compartments.

Deep and superficial posterior compartments: Longitudinal incision is performed 2cm medial to the palpable medial edge of the tibia, attempting to leave an 8cm skin bridge. During subcutaneous dissection, the great saphenous vein and saphenous nerve should be identified and protected.

A fasciotomy should be performed to decompress the deep posterior compartment.

Once this has been completed, progress the dissection posteriorly along the medial surface of the tibia, beginning at the mid-shaft of the tibia. Moving proximally up the posterior tibia, release the distal half of the soleal attachment. Progressing distally, release the fascia separating the deep and superficial posterior compartments by longitudinal incision.

Viability assessment: Once each compartment has been released, tissue viability should be assessed. Healthy muscles will appear red/pink, will bleed on pin-prick and contract when stimulated by diathermy. Muscles that are pale/grey, oedematous and unresponsive are likely non-viable. However, they should be re-assessed at 48-hour intervals and debrided only once clearly declared non-viable.

While neurological injury is difficult to ascertain intra-operatively, vascular assessment of pulses and distal perfusion should be performed.

Closure: Following thorough irrigation, the fasciotomy incisions should each be left open with negative-pressure dressing coverage. The patient will need to return for re-look debridement at 48-hour intervals.

Final closure should be delayed until non-viable muscle has declared and been debrided, and tissue status has stabilised. Have a low threshold for coverage with split skin grafting. Delayed primary closure may be considered in young non-smokers, where the skin edges can be approximated without tension.

Structures at risk