A hard tissue injury is an injury to the skeletal system itself - the bone either cracks or breaks - as opposed to a soft tissue injury, which damages muscles, ligaments or tendons. This chapter covers two kinds of hard tissue injury: joint dislocation and bone fracture.
A dislocation (also called luxation) is a joint injury that forces the ends of two or more bones out of their normal position; a partial dislocation is called a subluxation. It is usually caused by a fall, a blow, or playing a contact sport, or by weakness in the muscles and tendons that normally hold the joint in place. Its symptoms are pain, swelling, bruising, instability of the joint, loss of the ability to move it, and a visibly deformed joint. Treatment ranges from medication and ice (to control pain while waiting to see a doctor), to manipulation (a doctor manually returning the bones to place), rest in a sling or splint, rehabilitation through physiotherapy, and, in severe cases where manipulation fails or blood vessels, nerves, muscles or ligaments are damaged, surgery.
A fracture is simply a break in a bone, usually from a direct impact such as a fall or a hard tackle (stress fractures are the exception - they build up over time from overuse rather than a single impact). The book names six fracture types. A Stress fracture develops gradually from repeatedly overloading a bone too quickly without enough recovery; it needs rest, ice, anti-inflammatory medication and about 6-8 weeks to heal. A Greenstick fracture happens in a young, still-soft bone, which bends rather than snapping cleanly - common in a childhood fall, treated with a removable splint. A Comminuted fracture is when a bone is broken, splintered or crushed into several pieces by a large direct or indirect force; because the pieces are jammed together, it usually needs surgery (open reduction with nails, wire or plates) to put them back in place. A Transverse fracture is a straight break running right across the bone, caused by force hitting the bone perpendicularly; it can often be treated with rest and a supportive brace. An Oblique fracture is a diagonal break across the bone, usually from a fall or similar trauma, and is treated according to its severity with anti-inflammatory medicine and/or resetting the bone. An Impacted fracture is when the two broken ends of the bone are driven into each other by the force of the injury (typically a fall from a height); a sling or splint keeps the bone still so the jammed ends don't move and cause further damage.
Across every one of these, the same pattern repeats: more force, more displacement and more fragmentation generally mean a more serious injury and a more involved treatment, moving from simple rest, right up to surgical fixation.