Case Teaching Notes
for
“A Spill at Parsenn Bowl: Knee Injury and Recovery”

by
Elaine S. Chapman, Department of Biology, Illinois College, Jacksonville, IL

Introduction / Background

Based on a real incident, this case features the situation encountered by an older woman who has been injured on a ski slope. Her classic knee injury, often referred to as the “Terrible Triad of O’Donahue,” is complicated by her age, the altitude (12,000 feet), and possible hypothermia. In a stepwise fashion, students are introduced to the evaluation of the injury, structure of the knee joint, complicating factors, treatment of the injury, rehabilitation, and the patient’s eventual recovery. The topic of the case is often of particular interest to college-aged student-athletes, many of whom have faced a similar injury. Most of the information is accessible from the textbook.

This case was specifically developed for use in the first semester of an anatomy and physiology two-semester sequence. This course is generally taken by biology or exercise science majors during their junior year; the pre-requisite is successful completion of an introductory human biology or general biology course. Most students have also completed general chemistry, and many have completed more advanced courses in the sciences. Nearly all the students are interested in some area of the health professions. With some modification, the case would be useful in an introductory anatomy and physiology or human biology course. Emphasizing the basic anatomy and the factors involved in healing, I introduced students in my human biology class to this case when they were studying the musculoskeletal system. An additional section on respiratory physiology could be added or the case could be re-examined during the respiratory unit of the course with a focus on respiratory rate, pO₂, pCO₂, erythropoietin, and the oxygen-hemoglobin saturation curve.

Objectives

Upon completion of this case, the student should be able to:

• Describe homeostatic mechanisms involved in maintaining body temperature under cold conditions.
• Locate the dorsalis pedis pulse.
• Describe the structure and function of the knee, including the:
  • lateral and medial collateral ligaments,
  • anterior and posterior cruciate ligaments,
  • the bony fit of the knee,
  • the muscles that cross the knee, and
  • the movements at the hinge joint of the knee.
• Compare and contrast the information obtained from an X-ray vs. an MRI.
• Explain the signs of inflammation.
• Define osteoarthritis.

Classroom Management

Students are given the case about the time that they have nearly completed their study of the skeletal system and just as they begin to learn about articulations. At this point in the semester, the students would be familiar with most of the anatomy (other than the dorsalis pedis pulse, which they can look up in their text), and they would be preparing for the exam on the skeletal system. During the first unit of the course, they would also have covered the concept of homeostasis, using temperature as an example, and been exposed to information about the various imaging methods. The only concept which remains to be introduced in this class is inflammation, but students are generally familiar with its cardinal signs from other courses and their own experiences. This case is also helpful as an introduction to the muscular system and the concept of muscle atrophy.

Approaches

There are a variety of different approaches that could be used when teaching this case.

• The case could be distributed in hard-copy or on-line as a whole and discussed in a step-wise manner over several class periods. Our lecture periods are 70 minutes long, so I use the whole-case approach and divide the students into small groups of three or four. Students spend most of the class time discussing the case and have opportunities to work together outside of class. To make sure that students have a basic understanding of the case, I take a few minutes of the following class period to discuss the case and answer any remaining questions students may have.

• The case could be introduced in parts. By the time students have been in lecture for 50 minutes, they are often restless and need some more interactive and engaging approach to the material. Part I of the case could be introduced in the 10-20 remaining minutes after the lecture on homeostasis. Working in small groups, the students would be exposed to a real-life problem involving maintenance of body temperature. Later sections of the case could be presented in a similar manner following lectures on the appendicular skeleton and the joints.

• Students may also be assigned the entire case as a take-home essay exam on the appendicular skeleton and the joints. Students would have access to any and all reference materials (except other students!), and citations would be required.

• An adaptation of this case could be used in more introductory courses, such as human biology, or for more focused courses like care and treatment of athletic injuries. A modification of this case was used in my human biology class; that course focused primarily on the movements at the knee, basic anatomy of the knee, and factors involved in healing. A simplified outline of the case was distributed during a lab period in which the structure and function of the knee was studied by viewing both disarticulated human bones and the intact human skeleton and dissecting fresh chicken legs. (The anterior cruciate ligament is clearly visible in the chicken knee.)

Assessment

There are also a number of ways to assess student learning.

• Questions from the case can be included in traditional exams in essay, short answer, and multiple choice formats.

• As part (20%) of the skeleton/articulation exam this year in my class, students first answered questions individually about the anatomy and physiology of the case; then they turned in that portion of the exam. At that point, another copy of that portion of the exam was given to each group. Grades were determined by taking an average of the individual scores in a group and then subtracting that from the group score; that number of points was added to the individual scores. This supplied incentive for students in the groups to work together and be somewhat responsible for the learning by the group members. If the group exam grade was better than the average of the individual exam grades in the group, that number of points was added to the individual grades. (Note: It was very interesting to observe the group discussions of the exam. Although I have not had enough experience with this approach to determine if it is a better learning tool than traditional exams, it was apparent to me that the students gained a considerable amount of knowledge from each other, or at least reinforced what they knew, as they revisited that portion of the exam right after they had looked at it individually.)

• Depending on class size and schedule, each small group of students could be asked to present one part of the case to the entire class, and their oral presentation would be graded by the instructor.

Answer Key

Answers to the questions posed in the case study are provided in a separate answer key to the case. Those answers are password-protected. To access the answers for this case, go to the key. You will be prompted for a username and password. If you have not yet registered with us, you can see whether you are eligible for an account by reviewing our password policy and then apply online or write to answerkey@sciencecases.org.

References

Souryal, T., and K. Adams. “Anterior Cruciate Ligament Injury.” emedicine. Last updated: January 2, 2009.

http://emedicine.medscape.com/article/307161-overview Last accessed: August 18, 2009.

Starkey, C., and J. Ryan. 2003. Orthopedic and Athletic Injury Evaluation Handbook. Philadelphia: F.A. Davis Company.

Tortora, G., and B. Derrickson. 2009. Principles of Anatomy and Physiology. 12^th edition. Hoboken, NJ: John Wiley and Sons, Inc.

Acknowledgements: This case was published with support from the National Science Foundation under CCLI Award #0341279. Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Date Posted: September 30, 2009.

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