Quadriceps Tendon Injury

The knee is the most complex joint in your body and uses a delicately balanced system of bones, ligaments, and other structures to allow you to run, jump, perform cutting movements, and other advanced activities. The knee is made up of three bones: the femur (thigh bone), the tibia (shin bone), and the patella (kneecap). The two joints of the knee are the tibiofemoral joint (between the femur and tibia bones, this is the main knee joint) and the patellofemoral joint (between the kneecap and the trochlea, a groove on the front of the femur). The fibula bone is a thin bone on the outside of your lower leg that does not contribute to the knee joint, but is important to ankle stability.  

Tendons: Two important tendons run along the front of the knee and help you bend and extend the knee.

• Quadriceps tendon: This tendon is formed by the thigh muscles along the front of the thigh and attaches to the top of the patella.

• Patellar tendon: This tendon runs from the bottom of the patella to the top of the tibia.

Injuries to the quadriceps tendon typically occur in middle-aged patients. Quadriceps tendon tears occur when the knee is subjected to a high load, such as a fall or a hard landing while playing sports. Quadriceps tendon tears can be partial (some intact tendon remains) or complete (no intact tendon remains).

Risk Factors for Quadriceps Tendon Injury

Patients with a history of tendinitis, or inflammation, of the quadriceps tendon are at an increased risk of injury to the tendon. Chronic diseases, such as kidney problems, diabetes, gout, and hyperparathyroidism, can also predispose patients to injury. Use of anabolic steroids or steroid injections to the area can weaken the tendon.

Symptoms & Diagnosis

Patients will feel a pop and pain at the top of the kneecap after a quadriceps tendon injury. Knee swelling and bruising will appear after the injury. Patients will have difficulty walking and will not be able to bend or extend the knee. Occasionally, patients will not be able to bear weight on the injured leg.

Quadriceps tendon injuries are diagnosed using physical examination and imaging studies to confirm the diagnosis. The physical examination is used to identify areas of pain, swelling, change in range of motion, and the position of the kneecap. X-rays are used to look at the bones of the knee and look for any fractures. MRI (magnetic resonance imaging) is an important part of the diagnosis and will allow evaluation of all the knee ligaments, meniscus, cartilage, and any other structures that may have been injured.

Treatment

Quadriceps tendon injuries are primarily treated with surgical repair, but some partial injuries may be amenable to non-surgical treatment. A thorough discussion of your options will happen at your visit.

Non-surgical treatment includes immobilization in a brace and crutches initially, followed by a physical therapy program to help you return to activities. Patients may also use anti-inflammatory medications to help with swelling and pain.

Surgical treatment consists of repairing the tendon injury. Early surgery (<2-3 weeks after injury) is critical to allow for maximal functional recovery. An open incision is used on the front of the knee and stitches are used to secure the tendon to the top of the patella through holes in the patella or with special anchors.