E4947. Review of Extensor Mechanism Pathology of the Knee
  1. Andrew Payomo; Mount Auburn Hospital
  2. Edward Marianacci; Mount Auburn Hospital
The extensor mechanism of the knee is a common site for injury, due to its pivotal role in routine gait, as well as athletic activities. An approach to extensor mechanism pathology can be structured by categorizing pathology by anatomy, acuity, clinical history, and demographics. An educational case review that includes this approach, coupled with side-by-side comparisons of different imaging modalities will reinforce understanding of knee extensor mechanism pathology.

Educational Goals / Teaching Points
Cases selected from our department demonstrate classic imaging findings at different points along the extensor mechanism, providing the reader with a structured approach to diagnose pathology. Radiography, ultrasound, CT, and MRI are used to demonstrate how the same findings appear across various modalities. Cases are also showcased with annotated figures, brief clinical history, and concise explanations.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The acute extensor mechanism pathology includes quadriceps muscle tear, quadriceps tendon tear, patella fracture, patellar sleeve avulsion fracture, patellar tendon tear, patella dislocation, and tibial tuberosity avulsion fracture. The chronic extensor mechanism pathology includes Osgood-Schlatter disease, jumper's knee, Sinding-Larsen-Johansson disease, prepatellar bursitis, anterior suprapatellar fat pad impingement syndrome, and patellar tendon-lateral femoral condyle friction syndrome.

By displaying annotated figures and structuring cases by anatomy, acuity, clinical history, and demographics, this educational case review will act as a foundational approach to knee extensor mechanism pathology.