What's Your Diagnosis? Emergency Department Management of Knee Pain

Welcome to this month’s What’s Your Diagnosis Challenge!

But before we begin, check to see if you got the previous case on Management of Traumatic Intracranial Hemorrhage in the Emergency Department correct.

Case Presentation: Emergency Department Management of Knee Pain

A 19-year-old woman presents with knee pain that she says becomes worse when she is running…

Her vital signs are: temperature, 37°C; heart rate, 72 beats/min; blood pressure, 114/68 mm Hg; and respiratory rate, 14 breaths/min. You note that she has a low body mass index and a history of amenorrhea.
On examination, she has no joint effusion, but her knee is quite tender on the medial femoral condyle.
She has been waiting some time for radiographic studies, and you wonder: does she really need that knee x-ray?

Case Conclusion

The decision was made to obtain radiographs based on the patient’s risk factors of amenorrhea and her underweight BMI. The patient’s radiographs were negative, and using shared decision-making with the patient, you both agreed to forego any further workup and for her to establish outpatient follow-up. She was given crutches, and made non–weight-bearing. She was directed to follow up with a sports medicine physician for an outpatient MRI to evaluate for a stress fracture.