The extremities and spine.

A variety of pearls, pitfalls, and updates related to the extremities and spine are discussed. Tricks of the trade regarding shoulder dislocations, easily missed fractures, radial head subluxation, and the approach to deep lacerations are discussed. In the pitfall section, potential difficulties in the evaluation of suspected nonaccidental trauma, compartment syndromes, partial cord syndromes, and hip pain in children are discussed. Finally, new information regarding cost-effective evaluation of knee and ankle injuries, as well as advances in ultrasound evaluation of shoulder and extremity injuries, is presented in the clinical updates section.