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Patellar Tendon vs ACL Injuries: Differences and Treatment


Do you have persistent pain in your knee? Find out the differences between patellar tendon vs ACL injuries. You might think it is because you have patellar tendonitis, commonly called “jumper’s knee.” But it could be a torn anterior cruciate ligament (ACL). Both are in the knee, and both are due to sports or intense workouts.

These two injuries can be difficult to distinguish because the symptoms are pain, swelling, and irritation. But some key differences can help you figure out which one you have. You can also get proper treatment once you know your anterior knee pain diagnosis.

What is Patellar Tendonitis?

Athletes are susceptible to overuse injuries, and patellar tendonitis is one of them. It is an inflammation or irritation of the patellar tendon. This tendon attaches the kneecap (patella) to the shin bone (tibia).

Patellar tendonitis is also called jumper’s knee because it is common in basketball players and other jumpers. The constant jumping puts a lot of stress on the tendon, leading to inflammation.

Patellar tendonitis is a degenerative condition meaning it gets worse over time. But with proper treatment, you can improve your symptoms and protect your knee from further damage.

What is an ACL Tear?

The ACL is one of the main ligaments in your knee. It connects your femur (thighbone) to your tibia (shinbone). The ACL helps stabilize your knee by preventing your shinbone from sliding forward on your thighbone.

An ACL tear is a common knee injury, especially in athletes. A tear can happen when you stop suddenly, change direction quickly, or land from a jump incorrectly.

You might hear a “popping” sound when you tear your ACL. You will also likely feel pain and swelling. Your knee may feel unstable like your leg is going to give out from under you.

ACL tears can be partial or complete. A complete tear is more severe because the ligament has been completely severed.

Difference Between Patellar Tendonitis and an ACL Tear:

Patellar tendonitis and an ACL tear are two common knee injuries, but they are very different.

Here is how to tell them apart.

Patellar Tendonitis

Patellar tendonitis is a condition that causes pain and inflammation in the patellar tendon. This tendon connects the kneecap (patella) to the shinbone (tibia). It helps the leg extend when you walk, run, or jump. It also helps absorb shock when you land.

When you overuse your knee, this tendon can become irritated and inflamed. It can also be caused by sudden changes in activity level, such as increasing your mileage too quickly when you run. 

This condition is also known as “jumper’s knee” because it’s common in young athletes who do a lot of jumping, such as basketball players and volleyball players. Patellar tendonitis can also occur in people with weak thigh muscles or flat feet.

Symptoms of patellar tendonitis include:

  • Pain and tenderness in the front of the knee, around the patella (kneecap)
  • Pain that gets worse when you walk, run, or jump
  • Pain that gets worse after sitting for a long time with your knees bent
  • Stiffness in the knee
  • Difficulty straightening your leg fully

Anterior Cruciate Ligament Tears

An anterior cruciate ligament (ACL) tear is one of the most common knee injuries. The ACL is a ligament (strong tissue band) connecting the thighbone to the shinbone. It helps keep your knee stable.

A tear usually happens when you suddenly change direction while your foot is planted. It can also happen if you slow down quickly or land from a jump with your knee bent. ACL tears are common in contact sports, such as football and soccer, but they can also occur in non-contact sports, such as skiing.

Generally, ACL tears are classified as partial or complete. A partial tear means the tissue is still partly attached to the bone. A complete tear means that the tissue has been completely detached from the bone.

Symptoms of an ACL tear include:

  • A “popping” sound when the injury occurs
  • Severe pain and swelling in the knee
  • Knee instability
  • Inability to put weight on the affected leg
  • A feeling like your knee is “giving out”

Treatment for Patellar Tendonitis vs an ACL Tear

Patellar Tendonitis Treatments:

Patellar tendonitis and ACL tears require different treatments. That is because they are two different injuries with separate causes and physical challenges.

Patellar tendonitis is usually treated with a combination of rest, ice, and physical therapy. You might also need to take anti-inflammatory medication to help reduce pain and swelling. Sometimes, you might also need a cortisone injection to help relieve pain.

If these treatments do not work, you might need surgery to remove any damaged tissue or to release the tension on the tendon.


ACL Tear Treatments:

ACL tears, on the other hand, usually require surgery to repair the damage. Generally, surgery is completed by providing a less invasive procedure, such as arthroscopic surgery for the anterior cruciate ligament reconstruction (ACL reconstruction).

The ACL reconstruction involves making small incisions and using a camera to see inside the knee. Once inside your knee joint, the orthopaedic surgeon uses a piece of tissue, or graft, to place the damaged ACL. The most common graft is the patellar tendon autograft (BPTP autograft).

The graft choice for ACL reconstruction is ultimately up to the surgeon.

Hamstring grafts, BPTP autografts, cadaver grafts, quadriceps tendon autografts, and Achilles tendon allografts are the most common types of grafts used in primary ACL reconstruction surgery.

In addition, you will also need physical therapy after surgery to help strengthen the muscles around your knee and improve your range of motion. Your physical therapists will help you with this.

Recovery Time for Patellar Tendonitis vs an ACL Tear

The recovery time for patellar tendonitis depends on the severity of the injury. For mild cases, you might only need a few weeks of treatment before you start to feel better. More severe cases might take several months for better results.

For example, if you have a partial tear of your patellar tendon, it might take 6 to 8 weeks for excellent results. But if you have a complete tear, it could take 3 to 6 months.

The recovery time for an ACL tear also depends on the severity of the injury. For a partial tear, you might be able to return to your normal activities in 4 to 6 weeks. But for a complete tear, it could take 9 months to a year to fully recover. In some cases, it might take even longer.

Patellar Tendon vs ACL Injury: Which is More Serious?

Knee pain is never fun. Whether you are dealing with a minor ache or a debilitating injury, it can put a serious damper on your quality of life

For athletes, knee pain can be especially concerning. After all, your knees are key in just about every sport. Even if the pain is temporary, it can still put a major crimp in your training schedule.

If you are dealing with knee pain, there is a good chance it is either patellar tendonitis or an ACL tear. Both injuries can be serious, but they require different treatments. 

The severity of patellar tendonitis and torn ACL can vary. For some people, patellar tendonitis is a minor annoyance that will go away with time and rest. But for others, it can be a chronic condition that requires ongoing treatment.

So, which is more serious: patellar tendonitis or an ACL tear? The answer is not always clear. It depends on the individual and the severity of the injury.

In general, however, ACL tears are more severe than patellar tendonitis. This is because ACL tears require surgery to repair the damage, while patellar tendonitis may not.

Of course, this is not always the case. Some people with patellar tendonitis may need surgery to correct the problem. Some people with ACL tears may be able to avoid surgery if the knee is still stable enough for the patient’s daily activities.

It is also worth noting that these injuries can be serious for athletes. Patellar tendonitis can make it challenging to train, while an ACL tear can sideline you for months (or even years).

Who is more likely to have patellar tendonitis or ACL Injuries?

Some factors that may increase your risk of developing patellar tendonitis or tearing your ACL include:

Age: Age is a risk factor for both patellar tendonitis and ACL tears. Patellar tendonitis is more common in young adults, which is also true for ACL tears.

Sex: Female athletes are at a higher risk of ACL tears than male athletes. Some research suggests that this is due to anatomical differences, such as narrower hips and different muscle firing patterns.

Athletes: Patellar tendonitis is more common in athletes, particularly those who participate in jumping or running sports. ACL tears are also more common in athletes, especially those who play contact sports.

Flat Feet: Patellar tendonitis is more common in people with flat feet. This is because the position of the foot puts extra strain on the patellar tendon.

Obesity: People who are obese or overweight are at a higher risk of developing patellar tendonitis.

History of patellofemoral pain syndrome (PFPS): PFPS is a condition that causes pain around the kneecap. People with PFPS are more likely to develop patellar tendonitis.

What Activities Lead to These Injuries?

Some activities that may increase your risk of developing patellar tendonitis or ACL tears include:

Playing high-impact sports: Sports that involve jumping and sudden changes in direction, such as basketball, volleyball, and soccer, may increase your risk of ACL injury. People who participate in activities that put repetitive stress on the knees — may be more likely to develop patellar tendonitis.

 These activities include long-distance running, stair climbing, and deep knee bends.

Wearing high heels: Wearing high heels can contribute to the development of patellar tendonitis. This is because high heels change the alignment of the leg and put extra strain on the patellar tendon.

Dancing: The repetitive jumping and turning motions associated with dancing can put stress on the knees and lead to patellar tendonitis or ACL tears.


How can you prevent patellar tendonitis or ACL tears?

There are several things you can do to reduce your risk of developing patellar tendonitis or ACL tears, including:

  • Warm up before participating in any physical activity.
  • Stretch your hamstrings and quadriceps muscles.
  • Wear supportive shoes that are designed for the specific activity you are participating in.
  • Use joint-centric training that strengthens the knee joint.
  • Use proper technique when participating in sports or other activities.
  • Lose weight to reduce the strain on your knees.

Graft Type

If you have an anterior cruciate ligament (ACL) tear, your orthopedic surgeon will likely recommend surgery to repair it. Part of the surgery involves replacing the ACL with a new tendon. The two most common tendons used for this are the patellar tendon and the hamstring tendon.

Your orthopedic surgeon will choose the type of new graft options based on many factors, including:

  • Your age
  • The severity of your injury
  • The size of the tear
  • How active you are
  • Whether you have had ACL surgery before

Patellar Tendon Graft

The patellar tendon is one of the strongest tendons in the body. During surgery, a small piece of the patellar tendon is taken along with a small piece of bone from the kneecap. This graft selection is then used to replace the ACL.

This method is the gold standard for ACL surgery and is also called the bone-patellar tendon-bone (BPTB autograft) graft. A recent study has shown autografts have a lower risk of re-tearing and give the knee more stability than allografts. 

The patellar tendon graft has a faster recovery time than the hamstring tendon graft. The patellar tendon group had a significantly higher success rate than failure rates in returning to the same pre-injury activity level.

Hamstring Tendon Grafts:

The hamstrings are the muscles in the back of the thigh that help you maintain a stable knee, bend your knee, and kick your leg back. The hamstring autograft (or ht autograft) comprises two tendons (the semitendinosus and gracilis) that are taken from the hamstring muscles. The hamstring tendon graft is becoming more common because it has a lower risk of donor site complications (injuries at the site where the tendon was removed).

The main disadvantage of the hamstring tendon graft is that it has a slower healing rate than the patellar tendon graft.

Systematic review shows no significant difference in the re-tear rate between the patellar tendon grafts and the hamstring autograft grafts. 


Patellar tendonitis and ACL tears are both common injuries that can occur from participating in physical activity. There are several ways to prevent these injuries, including stretching, warming up, and wearing supportive shoes. If you do suffer from an ACL tear, your orthopedic surgeon will likely recommend surgery to repair it.

The two most common graft options for this surgery are the patellar tendon and the hamstring tendon. Each option has its own advantages and disadvantages, so your orthopedic surgeon will choose the best option for you based on your individual case.

If you or a loved one are struggling with these injuries, it is important to seek professional help in order to create the best treatment plan possible. With the help of an orthopedic surgeon, you can get back to your favorite activities without worry.