Back on Track

​The 14-year-old girl said she was running when she suddenly developed knee pain. Shortly after, she had trouble walking. She said she had not fallen before the pain, and no one was around her when it happened.Her knee was modestly swollen and diffusely tender anteriorly, and she could not lift it off the bed because of the pain.I assumed I would see a high-riding patella from a patellar tendon rupture or a transverse patellar fracture. After 30 years in emergency medicine, I wasn't expecting to see something I had never seen before—a cortical disruption at the posterior aspect of the inferior pole of the kneecap. How could this have happened?My best guess was that a lateral patellar dislocation spontaneously reduced. When it relocated, the posterior aspect likely struck the lateral femoral condyle, knocking off a fragment of bone.Spontaneous dislocations are particularly common in adolescent girls, and spontaneous relocations do happen. It is up to the emergency physician to assess for these because the patient often will not have a contact injury. Instead, it may be as simple as turning with a planted foot, causing the sesamoid bone to jump its track.Tip to Remember: Check the cortex of the bone completely. It is easy to miss what you are not expecting.Reference: Hasler CC, Studer D. Patella Instability in Children and Adolescents. EFORT Open Rev 2016;1(5):160; http://bit.ly/2EjDMTI.Tags: knee pain, running, trouble walking, patella, patellar tendon rupt...
Source: Lions and Tigers and Bears - Category: Emergency Medicine Tags: Blog Posts Source Type: blogs