LEG FASCIOTOMY (TWO-INCISION/ FOUR-COMPARTMENT FASCIOTOMY)
- What are the most common causes implicated in the development of compart- ment syndrome?
- Tibial diaphyseal fracture
- Soft tissue injury, including crush injuries
- Distal radius fracture (particularly young men with high-energy injuries)
- Diaphyseal forearm fracture
- Diaphyseal femoral fracture
- Tibial plateau fracture
- Other causes include burns, revascularisation, extravasation of IV fluid and exercise
- How would you position the patient to perform a leg fasciotomy?
I would position the patient supine with a thigh tourniquet applied but not inflated. I would place a sandbag under the ipsilateral buttock to ‘roll the lower limb in’ and to allow access to the lateral aspect of the leg. Following completion of the lateral fasci- otomy I would ask the theatre floor staff to remove the sandbag so that the lower limb ‘rolls out’ to allow access for the medial fasciotomy.
- Where would you base your incisions and what structures must be avoided?
I would utilise a two-incision approach. The lateral incision will be used to decom- press the anterior and lateral compartments. This is based 3–4 cm lateral to the anterior tibial border, midway between the tibia and the fibula.
The medial incision will be used to decompress the superficial and deep posterior compartments. This is based 1–2 cm posterior to the medial tibial border. The medial incision must be anterior to the posterior tibial artery in order to avoid injuring the 10-cm perforator on the medial side (this is usually the largest and most reliable for distally based fasciocutaneous flaps). There are 5/10/15 cm perforators on the medial side, measured at distances from the medial malleolus, although these are variable. The medial incision is also based anterior to avoid the saphenous vein and nerve.
One must be vigilant and ensure they leave a satisfactory skin bridge (>7 cm) between the two incisions to avoid potential necrosis of the skin bridge.
- Talk me through the superficial and deep dissection.
Lateral
Blunt dissection through fat distally to identify the superficial peroneal nerve (SPN) as it pierces the deep fascia (typically 10–15 cm proximal to the lateral malleolus).
Incise the deep fascia with a scalpel at the midpoint overlying the anterior com- partment, then extend proximally and distally with scissors with a closed tip.
Then incise the deep fascia overlying the lateral compartment in a similar fashion.
Medial
Blunt dissection through the fat to protect the long saphenous vein and saphe- nous nerve. Incise the deep fascia anterior to these as above with a scalpel and then closed-tip scissors to open the superficial posterior compartment.
To decompress the deep posterior compartment from the medial side, one must incise the fascia overlying FDL. Distally, this is superficial and can be incised directly.
Proximally, however, soleus is blocking access to the deep posterior compart- ment. Soleus should be detached from its tibial origin proximally (beware of vessels close to soleus origin) to expose the deep posterior compartment in the proximal half of the leg. The fascia over FDL is incised, with the NV bundle (posterior tibial artery, tibial nerve) being protected in its position between tibialis posterior and soleus.
I would then check muscular viability by assessing the 4 Cs:
- Contractility
- Colour
- Consistency
- Cut (does it bleed?)
Any necrotic tissue is then excised and wounds are left open for a second look with closure/coverage at 48 hours.
- What structures are at risk during this approach?
- Lateral: Superficial peroneal nerve
- Medial: 10 cm perforator, long saphenous vein, saphenous nerve