Rupture of the quadriceps tendon: diagnosis by arthrography.

Arthrography revealed an abnormal tract of contrast agent dissecting from the suprapatellar bursa into the soft tissue anterior to the patella and downward to a level 9 cm beneath the tibial plateau in a patient with complete rupture of the quadriceps tendon. The bursal anatomy of the anterior portion of the knee is reviewed in relation to the capsule-forming structures of the quadriceps expansion. The use of knee arthrography for the assessment of quadriceps tendon injury is advocated.