Fractures are one of the most common bone injuries. One of the most common injuries that occurs to bones, particularly the longer bones of the arms and legs is a fracture, or a break in the bone. Such fractures include multiple fractures with displacement of bones, comminuted sections, and even bone piercing skin (see figure 3.4).
Pivoting and cutting sports (soccer and basketball) are the most common scenarios for noncontact ACL injuries, whereas most direct contact ACL injuries occur in American football. ACL tears can be associated with meniscal tears or collateral ligament injuries. Critical to diagnosis of the ACL tear is the Lachman test, which evaluates the ACL laxity at 30 degrees of knee flexion and includes the uninjured knee for comparison.