quadriceps tendon rupture quadriceps tendon rupture a quadriceps tendon rupture is a tear of the tendon that runs from the quadriceps muscle to the top of the knee cap. quadriceps tendon ruptureother namesquadriceps tendon tearan x-ray demonstrating quadriceps tendon rupture. note the abnormal angle of the patella and soft-tissue swelling marked by the arrow.specialtyorthopedic signs and symptoms symptoms are pain and the inability to extend the knee against resistance. a gap can often be palpated at the tendon's normal location. diagnosis the diagnosis is usually made clinically, but ultrasound or mri can be used if there is any doubt. quadriceps tendon rupture in plain x-ray quadriceps tendon rupture in plain x-ray: incomplete rupture with haematoma in tendon. quadriceps tendon rupture in plain x-ray x-ray of a tear of the patellar tendon. on the left: the kneecap is pulled up. on the right: significant dent in the soft tissue above the kneecap. operative image: 1. kneecap 2. upper patella pole with drill holes 3. stump of the quadriceps tendon treatment the tendon can be surgically repaired. afterwards a brace is given that prevents flexion of the knee. athletes who have had this injury generally return to action in about 9 months to a year.