A 40 year old female presents with right knee pain after she was struck by a truck’s tailgate.  She is unable to bear weight and rests her knee on the stretcher in extension.  What's the diagnosis?  (scroll down for answer)

Answer: Patellar tendon rupture

• This saggital xray shows the classic finding of "patella alta" or "high riding patella"
• On physical exam, patients often have a palpable defect at the level of injury
• Patients who frequently participate in sports requiring running or repetitive jumping may develop patellar tendinitis (or “jumper’s knee”) which makes them more prone to patellar tendon tears or rupture.
• Tendon rupture requires surgical repair