The Case of the Unlucky Hiker

Emily, a twenty-four year old Asian-American graduate student in animal behavior, spends her free time hiking in the mountains around her home observing the behavior of various animals in preparation for her graduate work. One afternoon, Emily decides to spend her time hiking on less frequented trails in hopes of working on walking quietly while carefully observing the area around her. As usual, she lets her housemates know where she is planning to go. After parking her car and checking her equipment and supplies, she signs in at the trailhead. The day is warm and Emily is careful to drink frequently to minimize her chances of becoming dehydrated. Also, she snacks while hiking to maintain adequate blood glucose. As she rounds a bend in the trail, Emily notices a small herd of deer in the ravine below her and decides to try to move closer to them. After carefully checking the wind she starts to slowly move down the slope toward an overhanging ledge she noticed about halfway down. As she approaches the ledge, Emily looses her footing and begins to slide down the side of the ravine. She tries to catch herself at the ledge, but falls over the side of the ledge twisting her left knee and landing awkwardly on her left side. She continues to slide down the slope and finally comes to a stop at the edge of a grove of fir trees. While she does not loose consciousness, Emily is stunned and it takes her a few minutes to regain her composure. The first thing she notices is that her left leg is at an awkward angle and her left knee is very painful. When she tries to get up, she experiences pain in her left knee.

Remembering that human anatomy is not that different from the anatomy of most mammals and the minimal experience she has from a mandatory first aid course she feels fairly certain that she can draw some conclusions about her condition. Emily remains seated and uses her hands and a camping mirror from her daypack to evaluate her condition. Other than some minor scrapes and scratches Emily feels certain that she has not sustained any injuries to her arms, shoulders, ribs or abdominal organs. While she can not be certain, she also believes that she has not sustained any injuries to her head, although she may have a mild concussion. Emily also can not detect any extreme tenderness or swelling in her abdominal region or ribs. Her right leg and shin seem to be "normal", however her left knee appears to be injured and is swelling quite rapidly. Emily arranges her daypack so she can elevate left leg and begins to think about the best way to progress. As she is thinking, Emily hears what sounds like voices coming from above her. She uses her whistle to signal to the people she hears. When they respond she yells to tell them where she left the trail and what happened to her. The people on the trail above her tell her that they will mark the location and return to the ranger station to send some help back. Emily replies that she thinks she may have injured her left knee and she will wait until help arrives.

While waiting for help, Emily continues to monitor her situation. She begins to feel chilled, so she puts her jacket on and has something to eat and drink. She also tries to remain alert by counting the number of bird species she notices. Approximately 90 minutes later she hears voices calling to her from above. She attempts to direct the rescue team to her position and within 30 minutes they arrive and complete a field evaluation. Their diagnosis concurs with Emily's and they transport her to the trail and then to the regional hospital. At the hospital Emily receives a thorough physical examination by an emergency room physician. She tells the emergency room physician that she thought she heard a "popping" sound when she twisted her knee as she started to fall. The results of this examination indicate that Emily has not suffered any major injuries other than torn knee ligaments in her left knee. The emergency room physician immobilizes the leg and calls for an orthopedic consultation regarding her knee. The results of the magnetic resonance image (MRI) of her knee indicate a torn anterior cruciate ligament and medial meniscus. Emily is scheduled for surgery to repair her knee the next day and kept in the hospital overnight for observation.

The next morning the orthopedic surgeon explains to Emily that he will be taking a piece of one of her tendons to replace the torn knee ligaments and that this procedure will be done with the use of an arthroscope. The surgeon also explains that Emily should begin physical therapy as soon as possible after surgery to minimize her recovery time. After a successful surgery, without complication, Emily awakens and is discharged after being instructed in the proper use of crutches and the degree to which she can "move". Two days later Emily is evaluated by a physical therapist and given a series of rehabilitation exercises to complete each day. Gradually, Emily regains strength and stability in her left knee and is given a series of exercises to complete three to four times each day.

1			Define the bold terms in the text.
2			How does the anatomy of the knee differ from the anatomy of the elbow?
3			How do the cruciate ligaments in the knee aid in maintaining stability of the joint?
4			Why does swelling occur in Emily’s left knee following the injury?
5			Why was Emily kept in the hospital overnight for observation?
6			What are the purposes of the rehabilitation exercises Emily is expected to complete?