What's the Diagnosis? By Dr. Lauren Murphy

A 59 yo male presented to the Emergency Department after a slip and fall on his knee, directly onto concrete.  He complained of knee pain and swelling.  On exam he was unable to flex his knee. The x-ray is shown below.  What's the diagnosis?  Scroll down for answer.






Answer:  Comminuted Patella Fracture




  • Patella fractures most often occur with a direct blow to the patella, but may also occur with forceful contraction of the quadriceps muscle
  • Simple transverse fractures are the most common type, followed by stellate, and then comminuted fractures
  • Some patients may be treated without surgical repair; these patients must have intact extensor mechanism of the knee, <2mm of step-off, and <3mm of fracture displacement
  • Comminuted fractures such as the one above require surgical repair
  • Any open fracture requires IV antibiotics to cover staphylococcus






Tintinalli et al.  Tintinalli’s Emergency Medicine: A Comprehensive Study Guide.  8th Ed.  New York:  McGraw hill Education, 2016. Print