155 Common Injuries and Disorders of the Skeletal System LESSON 4.5 treatments for these common bone injuries and disorders are summarized in Figure 4.32 and are discussed further in this lesson. Fractures A fracture is a break or a crack in a bone. The nature of a fracture depends on the size, direction, and duration of the injurious force, as well as the health and maturity of the bone. Fractures are classified as simple when the bone ends remain within the surrounding soft tissues, and compound when one or both bone ends protrude from the skin. When the bone is splintered, the fracture is classified as comminuted. See Figure 4.33. An avulsion is a fracture caused when a tendon or ligament pulls away from its attachment to a bone, taking a small chip of bone with it. Explosive throwing and jumping movements may cause avulsion fractures of the medial epicondyle (ehp-i-KAHN-dighl) of the humerus and the calcaneus. Forceful bending and twisting movements can produce spiral fractures of the long bones. A common example occurs during downhill skiing. When a ski is planted in one direction, and the skier rotates while falling in a different direction, a spiral fracture of the tibia can result. Before You Read Try to answer the following questions before you read this lesson. What is the female athlete triad, and why is it potentially deadly? What is osteoarthritis, and how might it possibly be prevented? Lesson Objectives • Identify the different types of bone and epiphyseal injuries, and in each case explain the types of forces that can cause these injuries. • Discuss osteoporosis, including contributing factors, groups at risk, consequences, and prevention strategies. • Describe the common types of joint injuries, including the structures affected and symptoms. • Describe specific types of arthritis, including symptoms. Key Terms amenorrhea anorexia nervosa apophysis arthritis avulsion bulimia nervosa bursitis dislocation female athlete triad fracture osteoarthritis osteopenia osteoporosis rheumatoid arthritis sprain stress fracture Injuries and disorders of the skeletal system include problems with bones, joints, and the articular tissues. This lesson discusses many of the most common disorders. Common Bone Injuries Considering all of the important functions performed by bone, bone health is a vital part of general health. Bone health can be diminished by injuries and pathologies. The etiology, strategies for prevention, pathology, diagnosis, and common Joan is an outside hitter on her high school varsity volleyball team. Recently the shoulder of her hitting arm has been stiff and somewhat achy when she first wakes up in the morning. After a long, hard team practice the shoulder is quite painful. Joan does not recall having done or experienced anything unusual to injure her shoulder. As you read this section, try to determine which of the following conditions Joan most likely has. A. Stress fracture B. Sprain C. Bursitis D. Arthritis CLINICAL CASE STUDY Copyright Goodheart-Willcox Co., Inc.