A 19-year-old man sustains a closed tibial shaft fracture in a football injury. Six hours after intramedullary nailing, he complains of severe pain out of proportion to the injury, worsened by passive toe extension. The foot is warm with a palpable dorsalis pedis pulse. What is the most reliable method to confirm the diagnosis of acute compartment syndrome?
- A Paresthesia in the first web space
- B Absent dorsalis pedis pulse
- C Compartment pressure measurement showing a delta pressure (diastolic BP minus compartment pressure) less than 30 mmHg ✓
- D Skin mottling and cyanosis of the foot
Correct answer: C. Compartment pressure measurement showing a delta pressure (diastolic BP minus compartment pressure) less than 30 mmHg
Explanation
Compartment pressure measurement is the objective diagnostic standard. A delta pressure (diastolic blood pressure minus compartment pressure) below 30 mmHg confirms the diagnosis. Paresthesia is an early clinical sign but not confirmatory. Pulses and skin changes remain normal until very late, as compartment syndrome is a microcirculatory problem; palpable pulses do not exclude the diagnosis.
Reference: Rockwood and Green's Fractures in Adults, 9th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.