IS Case 262: Patellar tendon rupture

Meena Moorthy, MD, MBA

Imaging Sciences URMC 2009
Publication Date: 2009-06-26


Patient is a 22-year-old male post-trauma with severe left knee pain.


A lateral view of the left knee demonstrates a high riding patella. The patellar tendon is indistinct with two distinct calcified ossifications superior to the tibial insertion and inferior to the patella. The tissue plains posterior to the patellar tendon are indistinct.


Patellar tendon rupture is an injury that generally occurs secondary to trauma, usually a fall onto a bent knee, and is most commonly seen in athletes. The patellar tendon attaches to the inferior portion of the patella, and the tibial tubercle, allowing the knee to flex and extend.

In patellar rupture, the tendon loses its attachment to the tibia, and the patient is unable to straighten the knee. It can be very painful, and the patient will be unable to stand, due to the inability to extend the knee. Plain radiograph findings include a lack of definition of the patellar tendon and a widening of the AP diameter secondary to hemorrhage and edema. In some cases, the patella with be in a higher than normal position.

MR can be used to better define the injury, and treatment is surgical repair. Because the tendon is outside the knee joint, the procedure cannot be done athroscopically.


  1. Greenspan A. Orthopedic Imaging: A Practical Approach, 4th ed. Philadelphia: Lippincott Williams. & Wilkins, 2004: 287.

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