NURSING FUNDAMENTAL-chpt 50.docx

Patho Week 7 Quiz Musculoskeletal: A fracture is a break in the continuity of a bone. A break occurs when force is applied that exceeds the tensile or compressive strength of the bone. ● Types of Fracture: Classified as Complete or incomplete and Open or closed fracture. Complete fracture- the integrity of the bone is broken into two pieces Incomplete fracture- the bone is damaged but still in one piece. Types: greenstick, buckle or torus, and bowing. A greenstick fracture perforates one cortex and splinters the spongy bone and is relatively unstable. The term greenstick is derived from the damage sustained by a young tree branch (a green stick) when it is bent sharply. The outer surface of the bone (or tree branch) is disrupted, but the inner surface remains intact. Greenstick fractures typically occur in the metaphysis or diaphysis of the tibia, radius, and ulna. In a buckle or torus fracture, the cortex of the bone buckles but does not break, thus making it a relatively stable fracture. Bowing fractures usually occur when longitudinal force is applied to bone. Open fracture/Compound fracture-concurrent break in the skin in the area of the fracture. Closed Fracture/Simple fracture-no break in the surrounding skin. Fractures are classified according t o the direction of the fracture line. A linear fracture runs parallel to the long axis of the bone. An oblique fracture is a slanted fracture of the shaft of the bone. A spiral fracture encircles the bone. A transverse fracture occurs straight across the bone. A fracture in which a bone breaks into more than two fragments is termed a comminuted fracture. A fracture that results from a trauma that would not normally cause a fracture (a low-level trauma) is termed a fragility fracture. Fragility fractures are often a sequela of osteoporosis. Fractures may be further classified by cause as pathologic, stress, or transchondral fracture. A pathologic fracture is a break at the site of a preexisting abnormality (such as a tumor), usually by force that would not fracture a healthy bone. Any disease process that weakens a bone (especially the cortex) predisposes the bone to pathologic fracture. This type of fracture is most commonly associated with tumors, infections, osteoporosis, and other metabolic bone disorders. A stress fracture is caused by the cumulative effects of repeated forces over time, such as occurs during athletics. Subtypes: Fatigue and insufficiency fractures Fatigue fractures are caused by abnormal stress or torque applied to a bone with normal ability to deform and recover (e.g., joggers, dancers, military recruits). Insufficiency fractures include fragility fractures of osteoporosis and osteomalacia, and occur in bones lacking normal ability to deform and recover (i.e., normal weight bearing or activity fractures the bone). Transchondral Fractures: ● Consists of fragmentation and separation of a portion of the articular cartilage that covers the end of a bone at a joint. (Joint structures are defined in Chapter 44.) ● The fragments may consist of cartilage alone or cartilage and bone. ● Typical sites of transchondral fractures are the distal femur, the ankle, the kneecap, the elbow, and the wrist. ● Most prevalent in adolescents. Typical Complete Fractures 2 Closed fracture Skin overlying the bone is intact Open fracture Communicating wound between bone and skin Comminuted fracture Multiple bone fragments Linear fracture Fracture line parallel to long axis of bone Oblique fracture Fracture line at an angle to long axis of bone Spiral fracture Fracture line encircling bone (as in a spiral staircase) Transverse fracture Fracture line perpendicular to long axis of bone Impacted Fracture fragments are pushed into each other Pathologic Fracture occurs at a point in the bone weakened by disease (e.g., bones with tumors or osteoporosis) Avulsion A fragment of bone connected to a ligament or tendon breaks off from the main bone Compression Fracture is wedged or squeezed together on one side of bone Displaced Fracture with one, both, or all fragments out of normal alignment Extracapsular Fragment is close to the joint but remains outside the joint capsule Intracapsular Fragment extends into or is within the joint capsule Fragility Fracture caused by low-level trauma Typical Incomplete Fractures Greenstick fracture Break on one cortex of bone with splintering of inner bone surface (commonly occurs in children and older adults) Torus fracture Buckling of cortex Bowing fracture Bending of the bone Stress fracture Microfracture Transchondral fracture Separation of cartilaginous joint surface (articular cartilage) from main shaft of bone