Case 38: Ankle pain

Opening scenario

Olivia Allen, a 28-year-old female, comes to the physician because of pain in her right ankle.

Vital signs

• Temperature: 98.6°F (37°C)
• Blood pressure: 120/75 mm Hg
• Heart rate: 80/min
• Respirations: 16/min

Examinee tasks

• Take a focused history.
• Perform a relevant physical examination (do not perform corneal reflex, breast, pelvic/genitourinary, or rectal examinations).
• Explain the preliminary differential diagnoses and initial workup plan to the patient.
• Write the patient notes after leaving the room.

Patient instructions

• Wrap your right ankle in a bandage but leave out most of the right foot (including the heel and toes).
  • Use makeup, a pen, or paint to create a fake bruise on your right ankle. Alternatively, tell the examinee that there is a bruise on your right ankle after he/she removes the bandage.
• When your right leg is examined, pretend that it hurts to move the right ankle.
• When your right foot is examined, pretend that it hurts if the examinee presses on your ankle and the sole of your foot.
• You are not aware of the meanings of medical terms (e.g., MRI) and ask for clarification if the examinee uses them.
• Use the checklists below for history, physical examination, and communication and interpersonal skills.

Challenge: Your ankle is wrapped in a bandage. The examinee has to take off the bandage. Only then will it become evident that there is a bruise on your ankle.

Hovering over the speech bubbles in the lists below will reveal extra information about the adjacent term. However, clicking on links will cause you to navigate away from the current case, at which point your progress (i.e., your check marks) will be lost. If you do want more information on a subject, either open the link in a new tab or wait until you and your partner have finished the case and reviewed the check marks. Following the link to the patient note form will not interrupt your progress.

History of present illness

• Chief complaint
• My ankle hurts.
• Location
• It is my right ankle.
• Intensity (on a scale from 0–10)
• I would say that if I don't move the foot it is a 2. But if I move my foot it is really painful – I would give it a 6.
• Quality
• It is a dull pain.
• Onset
• It started 1 day ago.
• Precipitating events
• I was jogging and it was already dark. My right foot got caught and twisted up in a branch that was lying on the ground, and I tripped and fell. I'm training for a marathon right now, so this is really annoying.
• Progression/constant/intermittent
• It did not hurt right away but started a few hours later and has been pretty much the same since.
• Previous episodes
• None.
• Radiation
• Actually, the sole of my right foot hurts, too.
• Alleviating factors
• If I do not move my right foot.
• Aggravating factors
• If I move my right foot, it gets worse. But also standing on my right foot hurts.
• Associated symptoms
• None.

Review of systems specific to ankle pain

• Swelling of the ankle
• Not that I have noticed.
• Fever/chills
• No.
• Rash/skin changes
• I have not really looked today. Yesterday I did not see anything.
• Pain in joints
• Apart from my right foot no.
• Appetite
• I have been trying to eat less because I want to lose some weight for the marathon.
• Weight changes
• I lost some weight because I wanted to. Due to my good workout and nutrition schedule I lost 8 pounds in the past 4 months.
• Recent infections
• No.
• Altered sensation of right lower extremity
• No.
• Weakness of right lower extremity
• No.

Past medical history, family history, and social history

• Past medical history
• I had bacterial diarrhea a 2 months ago. I was given some antibiotics for it – think it was ciprofloxacin.
• Allergies
• None.
• Medications
• I take a vitamin A supplement every day to keep my skin looking youthful.
• Hospitalizations
• Never.
• Past surgical history
• None.
• Family history
• My father has gout.
• Work
• I work as a business consultant.
• Home
• I live alone.
• Alcohol
• Sometimes I have a glass of wine when I go out to dinner.
• Recreational drugs
• Never.
• Tobacco
• No.
• Exercise
• I go running every day, because I have to train for this marathon. It is the first marathon that I will take part in.
• Diet
• A lot of salad. I try to not eat too many calories.

• Washed hands
• Used respectful draping
• Extremities
  • Examination completed with bandage removed
  • Inspection of the lower extremities
    • Hematoma over the right ankle
  • Palpation of pedal pulses
  • Palpation of the the feet and ankles
    • Malleoli and sole tender to palpation on the right
  • Palpation of the right proximal fibula
  • Focused examination of passive and active motion of the lower extremities
    • Movement of the ankle painful on the right
  • Focused examination of sensation of the lower extremities

After trauma to a joint, always assess peripheral blood supply as well as motor and sensory functions and compare them with the uninjured joint.

Patient interaction

• Examinee knocked on the door.
• Examinee introduced him- or herself and identified his/her role.
• Examinee correctly used the patient's name.
• Examinee asked open-ended questions.
• Examinee listened attentively (did not interrupt the patient).
• Examinee showed interest in the patient as a person (i.e., appeared caring and showed respect).
• Examinee demonstrated the ability to support the patient's emotions (i.e., offered words of support, asked for clarification).
• Examinee did not repeat painful maneuvers during physical examination.
• Examinee discussed initial diagnostic impressions with the patient.
• Examinee explained the management plan.
• Examinee used non-medical terms and provided reasons for planned steps in management.
• Examinee evaluated the patient's agreement with the next diagnostic steps.
• Examinee asked about concerns or questions.

Counseling and challenge

• Examinee appropriately reapplied the patient's bandage after the physical examination or told the patient that a nurse will come to reapply the bandage or apply a new bandage.
• Examinee reacted appropriately to challenge.

Patient note

Differential diagnoses

1. Ankle sprain: This type of injury is typically caused by a supination trauma or, less commonly, by a pronation trauma. The twisting movement the patient describes as the mechanism of injury in her case could also cause an ankle sprain. Symptoms include pain, tenderness to palpation, and hematoma, which are all seen in this patient. Although other symptoms of ankle sprain, such as increased joint laxity and tissue swelling, have not been found here, the lack of visible deformities and the relatively mild pain at rest make an ankle sprain the most likely diagnosis.
2. Ankle fracture is often caused by a supination or pronation injury due to a fall and can also be associated with pain, hematoma, and tenderness to palpation. However, the injury typically becomes apparent immediately after the trauma and presents with visible deformities, swelling, and/or intense pain, making it only the second most likely differential diagnosis in this case.
3. Metatarsal stress fracture: Stress fractures occur due to an increased load or increased frequency of physical activity (e.g., while training for a marathon). Caloric restriction and female sex are risk factors for stress fractures. Typical symptoms of a metatarsal fracture include swelling, tenderness, and pain in the forefoot with activity, which is relieved with rest. Although the fact that this patient's pain did not begin immediately after the injury makes a stress fracture likely, it would not explain her ankle pain and hematoma, making it only the third most likely differential diagnosis.

Remember that findings such as swelling and joint laxity are difficult to for the patient to simulate. They will almost always be negative in the exam even if they would likely be present in a real patient.

Diagnostic studies

• X-ray of the R foot and ankle: to assess for fractures
• X-ray of the R fibula: to assess for associated fractures of the fibula
• MRI of the right foot: definitive diagnosis of a stress fracture; conventional x-rays can appear normal in the first 2–3 weeks

Other differential diagnoses to consider

• Muscle strain
• Fracture of other bones of the foot (e.g., navicular fracture)
• Achillodynia (achilles tendinopathy)
• See also sports injuries.