Case Study: Topic

Case Study 1 : Structure and Function of the Musculoskeletal System

Jennifer belongs to a women's rugby team. At 23 years old, she has been playing for five years and trains daily to keep up her strength and stamina. During one game, she was injured. Unable to walk, she was carried off the field supported by her coach and an athletic therapist.

At the hospital, after an examination and MRI of her right knee, she was given her diagnosis. Jennifer suffered what is often termed the "O'Donoghue triad": a ruptured medial collateral ligament, a ruptured anterior cruciate ligament, and tear of the medial meniscus.

1. Jennifer's injury involved the complete tearing of two ligaments. What are the similarities and differences between the anatomy and function of ligaments and tendons?

2. Jennifer's rehabilitation will include techniques that will increase her joint proprioception. What is proprioception, and what will occur if this neural function is not restored?

3. The knee joint exemplifies a diarthrodial joint. What are the anatomy of the synovial membrane and the importance of synovial fluid in such a joint?

Case Study 2 : Disorders of Musculoskeletal Function: Trauma, Infection, Neoplasms

Marvin is a healthy, active 36-year-old who belongs to a martial arts club. Once a week he takes lessons in Judo, and on the weekends, he participates in local competitions. At his last competition, Marvin was paired with a skilled participant from another club.

His rival threw him to the mats, and as Marvin struggled, came down hard to pin him down. Marvin heard a snap, followed by instant pain in his left forearm.

Radiographs at the local hospital confirmed he suffered a transverse fracture of the distal aspect of his left ulna.

1. What are the typical signs and symptoms of a fracture? Why shortly after the injury does the pain temporarily subside?

2. How does a hematoma form, and what function does it serve in the process of healing a fracture?

3. Marvin was told he would be seeing a physiotherapist as his healing progressed. What are the muscular and joint changes that occur during immobilization and the ways Marvin and his physiotherapist can work to address these changes?

Case Study 3 : Disorders of Musculoskeletal Function: Developmental and Metabolic Disorders

Mandy is a 16-year-old competitive figure skater who practices several hours a day with her coach at the skating arena. Because of her extremely active lifestyle and restricted diet to maintain her athletic physique, she experiences ongoing amenorrhea. One day during practice, she landed a jump and fell to the ice in pain.

Her left foot swelled up almost immediately, making it difficult for her coach to remove the skate. At the hospital, radiographs revealed a fracture of the fifth metatarsal bone and general radiolucency of all the bones in her foot. A follow-up DXA revealed a bone mass of 2.7 standard deviations below mean.

1. What is the etiology of Mandy's premature osteoporosis, and how her condition is thought to contribute to a decrease in bone density?

2. Knowing what you do about bone mineralization, why does a deficiency of estrogen in women lead to osteoporotic change?

3. Osteoporosis and osteomalacia both involve abnormal bone mineralization. What are the general macroscopic differences of these two conditions?

Case Study 4 : Disorders of Musculoskeletal Function: Rheumatic Disorders

Rick is a 27-year-old who works in an accounting firm. He had started to experience lower back pain and stiffness that he thought were a result of the long hours he spent at his desk. More recently, however, he began to have sleep difficulties. He found that he often woke up during the night feeling hot and sometimes sweaty.

Furthermore, his back pain disrupted his sleep, particularly when it radiated around his pelvis and into his thighs. When his lack of sleep began to interfere with his work, he went to an osteopath to see what was wrong.

She listened to his case history carefully. Upon physical examination, she noted a slight decrease in his lumbar lordosis and a reduced range of movement in his lumbar spine. His blood tests revealed the presence of HLA-B27, an elevated ESR, and absence of RH. His radiograph showed evidence of sacroiliitis.

1. What is the likely diagnosis Rick received? What are the common clinical presentation and manifestations of the disease?

2. Why is osteoarthritis of the hips a potential secondary complication of this disease? What are the structural changes that occur in the articular cartilage of an osteoarthritic joint?

3. What is the effect of advanced ankylosing spondylitis on lung function?

Case Study 5 : Structure and Function of the Skin

Yael is an 18-year-old college student who is bothered by excessive perspiration. She knew she sweat a lot under her arms and kept antiperspirant in her schoolbag to use throughout the day. Yael's problem was not limited to under her arms, however.

Her hands and feet also perspired heavily, and it embarrassed her. She did not like holding her boyfriend's hand if her hands were particularly sweaty, and she had problems grasping her pen while in class because her palm became slippery. Yael suffered from a condition called primary focal hyperhidrosis, a condition involving hyperactive sweat glands in certain areas of the body.

1. What are the anatomical and functional differences between eccrine and apocrine glands?

2. What autonomic nervous system controls the function of thermoregulation of the skin? How do goosebumpsgoose bumps contribute to heat conservation?

3. Describe the location of the blood plexuses in the skin. How is blood circulation to the skin involved in thermoregulation?

Case Study 6 : Disorders of Skin Integrity and Function

Leonard works in the agriculture industry and raises beef cattle. At 60 years of age, he has spent most of his life working outdoors harvesting hay and tending to his herds. His wife was the first to notice a change in his skin. One day, after taking off his shirt, she noticed a significant change in the mole he had on his right shoulder. It not only was darker but was moist and appeared to have been bleeding at one point.

Surrounding the mole, his skin was red. His wife remembered hearing stories of Leonard working on his father's farm, spending long hours out in the hot sun even though his father had gone into the barn to work during the hottest part of the day. She insisted him go to the family physician to have it examined.

1. Leonard's physician performed a biopsy on the lesion and told Leonard he suspected the growth may be malignant melanoma. What cells are affected in this form of skin cancer? How might his childhood exposures to the sun predispose him to this form of cancer?

2. How do UVA and UVB rays contribute to the process of oncogenesis in skin cells?

3. The mole on Leonard's shoulder was a nevocellular nevus. What are the cellular composition and appearance of this type of mole before it underwent malignant change?