Patellar Tendon Tear

Diagnosis & Treatment in 2023

Dr. Pamela Mehta, MD

Table of Contents

What is a Patellar Tendon Tear?

The patellar tendon is a key part of your knee joint. A patellar tendon tear, also known as patellar tendon rupture, is when some or all of your patellar tendon tears apart. This means that some of the tendon fibers become loose and are no longer holding the joint together.

Think of your patellar tendon like a rope.

You have one main cord which is made up of many smaller strings woven together.

When a rope is pulled taut it can generally withstand a great deal of pulling force.

However, if a section of rope is damaged, a sudden pulling force might cause the rope to tear, resulting in loose frayed ends.

Dr. Mehta is an authority figure in the diagnosis and treatment of patellar tendon tears. In this article, we will dive into the specifics of this injury, including its causes, risk factors, diagnosis, and treatment options.

Patellar Tendon

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About the Patellar Tendon

The Patella, also known as the kneecap, is a small triangular bone in your knee joint. This bone protects your knee joint from trauma when you hit your knee against a hard surface. Besides protecting your knee from damage, the patella also helps you to straighten your leg.

The patellar tendon is a vital component of the knee. It connects the kneecap (patella) to the shinbone (tibia). It allows the leg to straighten when walking, running, and playing sports.

This means that any damage to the tendon can cause significant pain in the knee. It may also prevent you from being able to straighten your leg. 

A patellar tendon tear occurs when this tendon is partially or completely torn. This is often as a result of sudden forceful contraction or a direct blow to the knee.

Other conditions which involve the front of your knee can also lead to difficulty straightening your leg. These conditions include:

  • Patellar tendinitis
  • Patellar fracture
  • Patellar dislocation
  • Quadriceps tendon tear

Types of Patellar Tendon Tear

A patellar tendon tear can be complete, meaning the patella and tibia are no longer connected. It can also be partially torn. In a partial tear, the two structures are still connected by at least part of the patellar tendon.

Complete Patellar Tendon Tear

In a complete patellar tendon tear, the tendon has snapped into two (or more) pieces. It no longer connects the kneecap to the tibia.

This breaks the hinge mechanism between the patella and quadriceps and patellar tendons. You’re no longer able to straighten your leg, and your mobility will be affected.

Partial Patellar Tendon Tear

In a partial patellar tendon tear, the tendon still connects the kneecap to the tibia. However, fibers of the tendon cord have torn and become frayed.

Partial tears usually happen because of repetitive overuse of the knee joint. This can lead to small tears in the tendon fibers over time. They can also occur as a result of a sudden injury, such as a direct blow to the knee. A sudden contraction of the quadriceps muscle can also cause a partial tear.

A partial patellar tendon tear can present a variety of symptoms, including:

Frayed Rope partial
man who has injured his knee during sports

These symptoms can vary in severity depending on the extent of the injury. If you are experiencing any of these symptoms, you should seek medical attention as soon as you can. This way you can prevent any further damage.

A complete patellar tendon tear often requires surgery to regain full knee function. However, a partial tear may not always need surgery. Non-surgical interventions can include:

  • Rest
  • Ice on the knee joint
  • Physical therapy
  • Anti-inflammatory medications

Partial tears can still have a significant impact on knee function. They can progress to a complete tear if left untreated.

Acute vs Chronic Patellar Tendon Tear

Tendon tears are either acute (occurring suddenly) or chronic (slowly worsening over time).

Acute tendon tears are far more common than chronic tendon tears. Chronic patellar tendon tears (also known as neglected patellar tendon tears) are tears which are more than 2 weeks old. These are more difficult to treat, often requiring a complete reconstruction of the tendon.


Acute patellar tendon tear often occurs when the leg is suddenly straightened. This can occur during sporting activities which involve jumping. Upon landing, you will experience knee pain and might hear a popping sound or feel like your knee is giving way.

Patellar tendon tears can cause a variety of symptoms. These can range from mild discomfort to severe pain and limited mobility. Some common symptoms of a patellar tendon tear include:

  • Pain and tenderness in the front of the knee, particularly around the kneecap
  • Swelling and bruising around the affected area
  • Stiffness in the knee joint
  • Weakness or instability in the knee joint
  • Difficulty with activities that need you to bend or straighten your leg. This includes walking, running, jumping, or climbing stairs

These symptoms can develop over time or can occur suddenly as a result of a traumatic injury.

Take someone person who experiences a sudden fall or direct blow to the knee, for example. They may develop immediate pain, swelling, and difficulty weight-bearing. This is an example of an acute patellar tendon tear.

In another example, take a person who does sports that include jumping and landing. These include basketball or volleyball. This person may develop patellar tendon pain over time due to repetitive stress on the knee. This is likely a chronic tear.

If you’ve experienced any of these symptoms following a knee injury, you must seek medical ASAP. Delays in the treatment may mean you need a more complex surgical procedure. Delayed presentation might also lead to a more difficult recovery.

Who is at Risk of a Patellar Tendon Tear?

Research has shown that patellar tendon tears are a rare injury. It is more commonly seen in athletes who take part in high-impact sports. However, they can also occur in people over the age of 40 with a history of knee problems or chronic knee pain.

Rupture of the patellar tendon is more likely in patients with conditions that affect their joints.

Knee pain running

Risk factors include:

Patellar tendon rupture is usually the result of long-standing tendon degeneration. This leads to weakness in part of the tendon. Tears often happen when the knee is suddenly and forcefully straightened. This can happen during activities such as:

  • Running up stairs
  • Landing from a jump
  • Stopping to change directions suddenly while running

To prevent a patellar tendon tear, it is important to take necessary precautions. This includes good conditioning and technique, using proper equipment, and taking rest breaks. If you do experience a patellar tendon tear, early diagnosis, and treatment are essential for a successful recovery.

The grade of the tear is important to determine the appropriate treatment plan for you.

A mild or partial tear may be treated conservatively with rest, ice, and physical therapy. A more severe or complete tear may need surgical intervention to repair the tendon.

Treatment for Patellar Tendon Tear

Most patients with a complete patellar tendon tear will need surgery. This helps to prevent loss of mobility. If a tear or rupture is suspected, surgical treatment will take place as soon as possible. A significant delay in treatment may reduce the chances of a successful recovery.

For partial tendon tears, Dr. Mehta may be able to use non-surgical treatments. This is possible when the tear is mild and you are still able to straighten your leg well.

In rare cases, surgery might be too risky due to underlying medical conditions. In these cases, Dr. Mehta will consider the risks and will discuss the best options available to you.

Knee Physical Therapy

Non-Surgical Treatment

If surgery is not an option, Dr. Mehta will advise you on non-surgical treatment for a patellar tendon tear. This involves a brace that holds the knee completely immobilized in a straightened position.

During your recovery, you will have an exercise program. This will be supervised and directed by your doctor and physical therapist. This exercise program will slowly introduce more weight-bearing exercises. Eventually, you will be ready for the brace to come off.

Dr. Mehta will also discuss painkillers and anti-inflammatory medication. This can help you with knee pain and stiffness, and allow you to move better.

Surgical Repair

The two main options for surgery are a complete reconstruction or a tendon repair.

A primary tendon repair is a less complicated procedure. This is the preferred option for most patients. A primary repair is performed if there is a suitable way to rejoin the torn tendon. This is done in a few different ways, depending on the location of the rupture.

If a primary repair is not performed soon after an acute tendon tear, adhesions form within the knee. This means that the tendon will begin to degenerate. A full tendon reconstruction may be the preferred option now, instead of a primary repair.

We choose a complete patellar tendon reconstruction when the tendon cannot be repaired. This might be because there is too much damage or there is chronic degeneration of the tendon. Tendon tissue from another part of the body is used to reconstruct the patellar tendon.

After surgery, your knee is placed in a brace to immobilize it for the initial part of the recovery. Outcomes for surgical treatment of patellar tendon tears are usually good. There is often an excellent response to surgery if a repair is performed soon after the injury. Recovery time depends on your individual factors and how well you complete the exercise programme.

Learn more about surgery for patellar tendon tears on our Patellar Surgery page.

Further Information

Learn about the causes of knee pain, what the diagnosis could be, and the treatments available.

Learn about knee surgery, including minimally invasive surgical techniques like knee arthroscopy.

Knee Conditions

Learn about different knee conditions, their symptoms, how they are diagnosed, and what treatment we can offer at Resilience Orthopedics, including: