A closed injury is an injury where the space at the site of the injury does not communicate with the external space of the body, or where the structure of the injury does not destroy subcutaneous tissue or visceral structures; this injury is usually called a closed injury. There are many kinds of closed injuries, common minor closed injuries include skin and subcutaneous soft tissue contusions, subcutaneous hematoma, joint sprains, ligament strains, ligament tears, injury fasciitis, muscle strain, cartilage injuries, tears, injury tenosynovitis, joint contusions, sprains, etc. are all minor closed injuries. Moderately severe closed injuries include closed fractures of the trunk of the limb, provided there is no damage to the mucous membrane of the skin or puncture of the skin to damage internal organs. Partial tears or even ruptures of ligaments and traumatic synovitis are also considered closed injuries. It is important to note that most fractures of the pelvis are open fractures, also called open injuries, because most fractures of the pelvis cause damage to internal organs, mucous membranes, and other structures.