The quadriceps muscle plays a vital role in the function and movement of the knee and leg as a whole. The quad muscle along with the quadriceps and patellar tendons work together to straighten your leg. Complete tears of the quad or patellar tendon are more common in adults. Running, jumping, or a fall may cause a tendon to rupture. Individuals who take steroids, certain antibiotics, or have certain chronic diseases have a higher incident of tendon rupture due to weakened tissue.
You may feel a tearing or “popping” sensation followed by swelling and pain when the quad or patella tendon is torn. Bruising, displaced kneecap, and the inability to straighten your leg can occur.
During examination, your doctor will see how well you can extend your knee. X-rays will often show a kneecap that is higher or lower than normal depending on what tendon is ruptured. MRIs are sometimes ordered to assess the tear. Most patients require surgery to attach the quad or patellar tendon back to the kneecap. After surgery, you will be required to wear a brace and remain non-weight bearing on the leg for a period of time to allow healing. Physical therapy will be important after surgery to regain motion and strength in the leg.