Quadriceps and patellar tendon rupture: what to know

The quadriceps tendon attaches the thigh muscles to the kneecap; the patellar tendon continues from the kneecap to the shinbone. Together they transmit muscle force so the knee can straighten. A rupture may cause sudden pain, swelling, bruising, a dip that can be felt, and difficulty standing or lifting the straight leg. The location of the tear helps distinguish the two injuries, but symptoms can overlap. A clinician may use an examination and imaging to check the tendon and decide whether the tear is partial or complete.

Stop sport and avoid putting unnecessary load through the leg. Keep the knee supported in the position advised by a clinician, use crutches if provided, and avoid repeatedly trying to straighten it. A complete rupture commonly requires a treatment plan that restores continuity, while selected partial injuries may be managed with protection and rehabilitation. If repair is recommended, rehabilitation is staged so healing is protected before strength and control are rebuilt.

Arrange urgent orthopaedic assessment after a sudden injury with loss of straight-leg raising, inability to bear weight, or a visible change in the knee shape. Seek emergency help for severe swelling with numbness, a cold or pale foot, chest pain, or difficult breathing. After treatment, promptly report wound drainage, fever, worsening redness, sudden loss of function, or a new pop.

Ask which tendon is torn, whether the tear is partial or complete, what support is needed now, whether repair is advised, and how movement and strengthening will be progressed safely.