Knee > Quadriceps Tendon Rupture

There are four muscles in the front of your thigh that make up the quadriceps muscle unit. These muscles attach to one quadriceps tendon, which attaches to the kneecap. When you flex your quadriceps muscles, the quadriceps tendon is what allows them to pull on the kneecap and straighten your leg. Off-balance falls or abnormal strain can completely tear your quadriceps tendon. This rupture usually happens just above the kneecap, close to where the quadriceps tendon attaches to the kneecap bone, leaving quadriceps muscles with nothing to pull on when they flex. Most people cannot straighten their leg when the quadriceps tendon ruptures.


Quadriceps tendon ruptures are rare in sports. To rupture the tendon, a large force is required and your knee usually must be bent well past 90 degrees, such as falling with your foot caught under your buttocks. Healthy knees are only at risk of suffering a ruptured quadriceps tendon during activities that involve high speeds, direct contact, or twisting ­ like skiing, football, and basketball. Landing from a jump incorrectly and heavy weightlifting can also rupture your quadriceps tendon. People over the age of 50 suffer the majority of quadriceps tendon tears. But at any age, a history of repeated knee injuries, previous knee surgery, or joint disease could put you at greater risk of a quadriceps tendon rupture. This means that less force could rupture your quadriceps tendon if you have suffered multiple microtears, or minor injuries over the years, and especially if you have a disease like rheumatoid arthritis that weakens the fiber material (collagen) in your tendons.


Although a ruptured quadriceps tendon is not a life-threatening emergency, you should seek treatment as soon as possible. Whenever possible, do not wait to see if your pain goes away on its own. Physicians generally suggest that you undergo surgery immediately after a tendon rupture. Surgery is most effective when performed within several days of the injury. However, if you wait more than two weeks to seek treatment, your ruptured tendon may begin to heal in an abnormal position, which makes repairing the tendon more difficult and decreases your chance of returning to activities at full strength. Non-operative treatments like ice and immobilization are ineffective. Ruptured quadriceps tendons almost always require surgery to sew the split tendon back together. Most quadriceps tendon ruptures occur in older people. However, anabolic steroid use puts young people at high risk of quadriceps tendon ruptures.

Orthopedic Evaluation [top]

There are usually three parts to an orthopedic evaluation: medical history, physical examination, and tests your physician may order.


Your doctor will likely ask you when your quadriceps tendon rupture occurred, how it has been feeling since the pain began, and if your knee has been previously injured. Physicians also typically ask about other conditions, such as diabetes and allergies, and medications currently being taken. The doctor may also ask about your physical and athletic goals ­ information that will help to decide what treatment might be best for you in achieving those goals.


A physician usually can make an early assessment of an injury by feeling around the area. Because the kneecap is easily visible, physicians can easily test for pain and tenderness. He probably will move your kneecap up and down. A ruptured quadriceps tendon usually causes your kneecap to move abnormally, downward toward your shin. The doctor sometimes can feel a defect where your quadriceps tendon has split in two. By moving your kneecap around to check how well it tracks as your leg bends up and down, physicians can often determine any underlying damage caused by a quadriceps tendon rupture.


Should your physician require a closer look, the following tests may be conducted:

   X-rays taken from different angles can occasionally show when your kneecap is out of place, signaling that the connection to the thigh muscles has been ruptured. Physicians usually take X-rays of both knees so they can see the position of the healthy kneecap and sew the ruptured tendon at a matching length.

   MRI (magnetic resonance imaging) may be used to see if the rupture has caused any bone, cartilage, or muscle problems.

   Arthroscopy, in which a tiny camera is inserted into your knee, may be used to determine the diagnosis in more detail. It is rarely needed to diagnose a tendon rupture but it may help your physician determine if any other injuries are present. Arthroscopy is usually done on an outpatient basis, and does not require a hospital stay.


   Imaging techniques

Surgical Tendon Repair

Copyright 2007 | Insall Scott Kelly® Institute. All Rights Reserved.