The most common history is trauma with a mid-shaft bone fracture. Other common injuries associated with compartment syndrome are crush injuries, burns, and penetrating trauma.
The physical exam will be notable for pain out of proportion to exam, and in particular pain with passive stretch of a muscle in the suspected compartment, which is more sensitive and specific than the other findings. The affected area will be exquisitely tender and may be tense, hard, or firm. The typical presentation is severe pain and swelling in the presence of a swollen compartment.
The classic findings of compartment syndrome are “The 5 P’s”:
- Pain (out of proportion on passive stretch)
- Polarity (cool distal extremity)
However once all these findings are present, the patient is in severe danger of non-reversible ischemia. It is important not to expect all of these findings to be present in order to make the diagnosis while muscle is still salvageable.