Compartment Syndrome (CS) can occur in many parts of the body – limbs, abdomen – this talk will focus on the limbs esp. the calf. CS has many different causes – ischemia, fracture, blast injury etc. CS in the leg should be thought of in 2 scenarios: 1. Established CS / Advanced CS with muscle necrosis, nerve damage; 2. Anticipated / possible CS Diagnosis & Management of these 2 is very different. 1. Diagnosis in Established / Advanced CS is usually straightforward, but comes “too late”. A full, open, 4 compartment fasciotomy should be performed +/- debride dead muscle +/- “bootlace” closure of the skin. An alternative is resection of the middle 1/3 of fibula thru a single incision. 2. In anticipated / possible CS, diagnosis is difficult, signs & symptoms vague & fluctuating & patient may be in a critical state complicating assessment. In this situation, fasciotomy should be performed very early & liberally, but the closed, 3 compartment fasciotomy should be used. Why the “closed” 3 compartment fasciotomy? a. Compared to the 4 compartment fasciotomy, it is minimally invasive, leaving 2 small (5cm) closed or open wounds, with minimal dissection, soft tissue damage, infective or healing problems. b. Being minimally invasive, it can & will be used liberally, frequently & early in all situations where the development of CS is considered, avoiding the occasional catastrophic Advanced CS. c. It avoids the complicated & unreliable “monitoring” of the development of CS in at risk limbs. Its main weakness is failure to open the Deep Posterior Compartment. However, this is affected uncommonly, esp. compared to Anterior Compartment. The closed fracture scenario can be approached in similar fashion, particularly by using prophylactic gypsotomy.