Examination of an Injured Extremity in Trauma

1. Look (Inspection)

• Expose and inspect the whole limb, front and back, comparing with the other side.
• Note deformity, angulation, shortening, rotation (e.g., a shortened, externally rotated leg suggests a proximal femur fracture; a flexed, adducted, internally rotated hip suggests posterior dislocation).
• Look for swelling, bruising, skin breaks/abrasions - any wound near a fracture must be documented and reported, since it may change management (e.g., a graze over the knee near a closed tibial fracture may delay intramedullary nailing until the wound heals).
• Note skin colour, degree of swelling, and any pre-existing surgical scars (which may indicate prior nerve transposition or hardware).
• Photograph open wounds (with consent) to avoid repeated dressing removal.
• Important caveat: a limb can harbor a developing compartment syndrome even without gross swelling - "looking normal" does not exclude it. (Bailey and Love's Short Practice of Surgery, 28th ed.)

2. Feel (Palpation)

• Start away from the area of obvious injury and work toward it, to build trust and avoid guarding.
• Palpate for bony tenderness, point of maximal tenderness, and crepitus (subcutaneous air crepitus suggests an open fracture or gas-forming infection).
• Assess compartment tenseness - but note tense compartments are not a reliable rule-out for compartment syndrome, and deep compartments (e.g., deep posterior compartment of the leg) cannot always be palpated through skin.
• Assess temperature and capillary refill, and palpate distal pulses. (Bailey and Love's Short Practice of Surgery, 28th ed.)

3. Move

• Assess active movement (patient-initiated) and passive movement (examiner-initiated) of the joint above and below the injury.
• Compare range of motion side to side; reduced or painful movement localizes injury.
• Movement testing should never be forced through obvious deformity or severe pain before imaging.

4. Neurovascular Examination (mandatory, and must be documented before AND after any reduction/splinting)

• Vascular: colour, temperature, capillary refill, and palpation/comparison of distal pulses (e.g., dorsalis pedis and posterior tibial for the leg, radial/ulnar for the arm). If pulses are asymmetric or absent, calculate an ankle-brachial index (ABI) - especially mandatory in knee dislocations - and pursue arteriography/CT angiography if abnormal.
• Neurological: test sensation and motor function of each named peripheral nerve at risk for that specific injury (e.g., radial, median, ulnar nerves in upper limb injuries; peroneal, tibial nerves in lower limb/knee injuries).
• The classic "6 Ps" of neurovascular/limb-threatening compromise: Pain (disproportionate), Pallor, Paresthesia, Paralysis, Pulselessness, Poikilothermia (temperature change).
• A baseline neurovascular exam at first assessment is essential - it is the reference point for detecting later deterioration (post-splinting, post-casting, post-reduction).

5. Specific red flags to actively exclude

• Compartment syndrome - disproportionate pain, pain on passive stretch, tense compartments; can coexist with normal-appearing skin and palpable pulses (pulses are often preserved until late). Do not rely on pulse presence to exclude it.
• Open fracture - any wound communicating with the fracture; document size, contamination, neurovascular status before wound manipulation.
• Associated injuries - always examine the joint proximal and distal to the fracture, and consider ipsilateral injuries (e.g., a femur fracture patient should have hip and knee specifically examined) - physical exam of dislocations/fractures may be unreliable due to pain, guarding, or spontaneous reduction, so a low threshold for imaging and repeat exam is warranted.
• Ligamentous instability testing (e.g., after knee dislocation) should only be performed once neurovascular status is confirmed safe. (Campbell's Operative Orthopaedics, 15th ed.; Rockwood and Green's Fractures in Adults, 10th ed.)

Documentation

1. ABCDE first (life over limb)
2. Look - deformity, wounds, swelling, colour
3. Feel - tenderness, crepitus, compartments, temperature, pulses
4. Move - active/passive ROM, joint above/below
5. Neurovascular exam - 6 Ps, document before/after any reduction
6. Exclude compartment syndrome and open fracture explicitly
7. Imaging (AP/lateral +/- oblique views; MRI/angiography as indicated)