What Happens With a Quadriceps Tendon Rupture

The quadriceps tendon is a thick, strong tendon that can withstand tremendous force. In daily life, it acts as part of the extensor mechanism to straighten the knee.

People who injure the extensor mechanism may tear the quad tendon, tear the patellar tendon, or fracture the kneecap. All of these injuries have similar treatments and rehabilitation plans.

The Quadriceps Tendon

The quadriceps tendon (quad tendon) is the large tendon just above your kneecap. The quad tendon is part of the extensor mechanism of the knee that includes the quadriceps muscle, the quad tendon, the kneecap (patella) and the patellar tendon.

It's the extensor mechanism that allows us to straighten our knee or perform a kicking motion.

When the quadriceps muscle (thigh muscle) contracts, force is transmitted through the quadriceps tendon, across the patella (kneecap), through the patellar tendon, and the knee is straightened.

Causes

Partial quad tendon injuries can occur in association with athletic activities or active lifestyles.

These symptoms may cause gradually increasing pain over the kneecap and may be misdiagnosed as a kneecap problem. An incomplete injury to the quadriceps tendon may be described as:

• Tendinitis
• Tendinosis
• Partial tearing of the quadriceps

The key to differentiating this is whether or not the tendon is completely torn away from the kneecap.

Complete quadriceps tendon tears are unusual injuries. They most often occur in people over the age of 40, and often in people who have systemic medical conditions that can cause weakening of the tendon.

The quadriceps tendon ruptures typically occur during an eccentric contraction where the quadriceps muscle is contracting, but the knee is being straightened. When this occurs, the sudden, opposing forces can exceed the strength of the quadriceps tendon.

An eccentric contraction can occur with injuries such as a slip on wet ground or a sports injury.

Symptoms and Diagnosis

If the tendon is completely ruptured, you'll be unable to straighten the knee without help and you'll be unable to perform a straight leg raise.

Most people with a quadriceps tendon rupture will have​ a swelling of the knee and your healthcare provider will be able to feel the torn tendon just above the kneecap. If the swelling isn't too severe, you may be able to see a divot or gap where the tear in the tendon is located.

X-rays can help your practitioner determine if the kneecap was damaged. While an MRI is usually not necessary, your medical professional may order the test to evaluate for other damage within the knee joint.

Treatment

Partial tears of the quadriceps tendon can usually be managed with non-surgical treatments, which may include the use of:

• Knee brace or immobilizer
• Ice application
• Anti-inflammatory medications
• Physical therapy
• Rest from athletic activities

Physical therapy can be especially beneficial by strengthening the quadriceps and surrounding muscles, and utilizing other modalities to stimulate healing of the tendon.

Complete tears of the quadriceps tendon require surgical intervention to regain strength in the extremity.

Surgery is usually done within a few weeks of the injury, as some reports have shown that delayed treatment may lead to less successful results. Surgery is performed to suture the torn tendon back to its attachment on the patella (kneecap).

In order to accomplish this, your surgeon will use a drill to make holes (tunnels) in the patella, and then loop sutures through these tunnels to pull the tendon to the bone.

Following surgery, most surgeons recommend a brace to protect the repair. You may also be put on crutches, although weight can be placed on the leg as long as the knee is kept straight.

Many surgeons allow early range of motion exercises, but this should be done under the supervision of a physical therapist or healthcare provider.

A Word From Verywell

A quadriceps tendon rupture is an uncommon injury that typically requires surgical treatment.

Without an intact quadriceps tendon, straightening the knee and walking normally can be difficult. During surgery, the tendon is reattached to the top of the kneecap bone.

Rehabilitation is lengthy following quadriceps tendon repair surgery, but most people recover normal activities.