Pain in the top, or front, of the knee — also known as anterior knee pain — has several possible causes. The exact location of the pain may be an indicator of the underlying issue.
Some causes, such as a minor injury or bruising, may heal without intervention. However, other underlying issues may require treatment. If a person is concerned about pain in their knee, they should consider contacting a doctor.
The knee is a complex joint, as it is the meeting point of various bones, muscles, and connective tissues. Doctors typically consider conditions to affect the “front” of the knee, rather than the “top.”
This article will examine some of the potential causes of anterior knee pain. It will also discuss some of the treatment options and preventive measures.
Pain in the front of the knee may occur for many reasons. Determining the site of pain and any other symptoms may help identify the underlying cause.
Some potential causes of anterior knee pain include:
Patellar tendinitis, or jumper’s knee, develops due to inflammation of the tendon that attaches the kneecap (patella) to the shin bone (tibia). This inflammation may occur due to activities that repeatedly stress the tendon, such as jumping and running.
In fact, some research notes that patellar tendonitis occurs in about 20% of jumping athletes.
The repetitive stress of jumping and running may lead to small tears in the tendon, resulting in inflammation and pain located at the bottom of the kneecap.
Other forms of tendonitis
Other inflamed tendons around the knee may also lead to pain in the front of the knee. The quadriceps and hamstring tendons, if involved, may also result in knee pain.
The quadriceps tendon connects the muscles on the front of the thigh to the top of the kneecap, whereas the hamstring tendons connect the muscles of the back of the thigh to the top of the tibia.
Damage to and inflammation of any of these tendons can also cause pain in the front of the knee.
Patellofemoral pain syndrome
Patellofemoral pain syndrome (PFPS) is a condition that causes pain in the front of the knee. An article in The Archives of Bone and Joint Surgery notes that PFPS is one of the most common causes of anterior knee pain.
PFPS may develop due to weakness of the muscles surrounding the hip and knee, which sometimes results in the kneecap not being correctly aligned, or due to repetitive stress on the knee joint through running, cycling, and jumping sports.
As people age, the protective cartilage at the ends of the bones may break down and lead to osteoarthritis. This may cause symptoms such as:
- a cracking or grinding sensation in the knee
One article in the Journal of Pain Research suggests that osteoarthritis is the most common form of arthritis and a common cause of disability.
Arthritis may occur in one or both knees and cause pain in the front of the knee or certain other joints.
Bursitis refers to inflammation of a bursa. The bursae provide cushioning and reduce friction between the bones and the overlying soft tissue structures, such as tendon, muscle, and fat.
Inflammation in the bursae in this area may cause pain or swelling in the front of the knee.
Something as simple as walking into a hard object may cause damage and bruising of the front of the knee. This can result in pain and tenderness at the site of impact.
Major trauma, such as from falls or vehicle accidents, may also cause knee damage, resulting in significant pain and disability.
Although minor injuries are generally temporary, if a person is concerned about their symptoms, it is best to visit a doctor for a full examination.
Several symptoms are associated with pain in the front of the knee, such as:
- pain when squatting or when climbing stairs
- pain while running or jogging
- pain in the front of the knee after sitting with the legs bent for long periods of time
- hearing popping or cracking sounds when bending the knee
- stiffness, especially when first waking up
- swelling in the front of the knee
- bruising around the knee
- the knee giving out or buckling under pressure
A person should always make note of any symptoms they experience and report them to their doctor during examination. Each symptom may help the doctor identify the underlying cause of the knee pain and make the correct diagnosis.
A doctor will conduct a physical exam of the knee and ask the person about their symptoms. They will also test the range of motion and stability of the knee and check for any signs of structural damage to the joint.
Other tests that may help them establish the correct diagnosis include:
Although X-ray and CT scans are useful for looking at the bones, an MRI scan may be useful for more closely examining the soft tissue structures around the knee, such as the ligament, tendon, and cartilage.
Treatments for knee pain often include resting, taking anti-inflammatory medication, and using cold compresses or ice packs to reduce swelling and pain. However, targeted treatment may vary based on the underlying cause or condition.
For example, physical therapy may help strengthen the muscles around the knee to reduce stress on the joint. Physical therapy may also help correct gait issues and other anomalies that may be contributing to the pain.
A doctor may also recommend therapies such as electrical stimulation or ultrasound to help reduce knee pain.
Sometimes, a doctor or physical therapist may recommend bracing or taping the knee. This can help reduce pain and keep the kneecap in alignment.
In rare cases, such as with a major tendon injury, surgical treatment may be necessary. Surgery aims to repair damaged tissue and restore the normal function of the knee.
Rehabilitation after surgery may take some time, and it usually involves physical therapy to restore normal range of motion, strengthen the muscles, and help the person return to their normal level of activity.
Preventing pain in the front of the knee is not always possible, but there are several things a person can do to keep their legs and knees healthy.
Regular exercise is a helpful tool to strengthen the body. For the knees specifically, a doctor may recommend a home exercise program that focuses on strengthening the muscles of the leg.
Regular stretching can help keep the muscles mobile and reduce stiffness.
Making dietary changes and taking nutritional supplements that can reduce inflammation may also help, but a person should always consult their doctor or dietitian before doing so.
Also, maintaining a moderate weight can help reduce impact on the joints, and this, in turn, may help prevent injury.
A doctor or physical therapist may recommend some exercises to strengthen the leg and knee muscles to help treat or prevent anterior knee pain.
The following are two examples of leg strengthening exercises. A doctor may provide instructions for other exercises depending on the underlying cause of a person’s knee pain.
Seated leg extensions
To perform this:
- Sit upright in a chair with the feet flat on the ground.
- Tighten the thigh muscle to raise one leg straight up in front of the body.
- Hold this position for 5 seconds, then slowly lower the leg back down.
- Repeat these steps as comfort allows, then switch to the other leg.
To perform this:
- Stand upright, holding a chair or the wall for balance.
- Bend the knee behind the body and bring the heel up behind the buttocks.
- Grasp the ankle with the hand and gently pull the heel closer to the body.
- Hold for 30–60 seconds, depending on comfort, then switch to the other leg and repeat.
Pain in the front of the knee may occur for a number of reasons, ranging from a mild injury to a more serious underlying condition. Identifying the underlying cause is essential in order for a doctor to be able to create an effective treatment plan.
Rest combined with targeted exercise to strengthen the surrounding muscles may help reduce the symptoms.
However, some underlying causes may require additional treatment methods. These methods may include:
- taking medications
- making dietary adjustments
- making certain lifestyle changes
- undergoing surgery
If a person is concerned about pain in the front of their knee, it is always best to contact a doctor for a full examination and diagnosis.