The pressure within your knee joint changes when you stretch or move the joint.
Air bubbles do not cause pain and are considered harmless.
Cartilage damage can lead to conditions like osteoarthritis.
Verywell / Emily Roberts
This can happen due to anoveruse injuryor when the knee joint bones are misaligned.
This can hinder knee extension, cause pain with knee flexion, and create joint instability.
Meniscus Tear
Knee popping can happen when there’s something mechanically wrong with the knee joint.
It may feel as if something is “catching” in the knee whenever it is bent.
These are all signs of a condition known as ameniscus tear.
Severe tears may requirearthroscopic debridementto trim and repair the injury.
In other cases,surgical reattachmentof the torn ends may be needed.
Knee Osteoarthritis
Knee crepitus is often an early sign ofknee osteoarthritis(OA).
Knee popping may occur without pain in the early stages and worsen as the otherOA symptomsdevelop.
Partial tear:In a partial tear, the tendon is stretched and potentially frayed but not torn through.
Conservative treatments, such as immobilization and physical therapy, are often effective, especially in smaller tears.
Knee Tendonitis
Knee popping can also be because of a problem with the knee’s tendons.
The most common punch in is callediliotibial band tendonitis.
The iliotibial (IT) band is a tendon that runs from your hip to just below your knee.
you could often feel the swollen and displaced tendon as you move the knee.
However, surgical intervention may be necessary if conservative treatments are ineffective.
Ligament Injuries
Four main ligaments in your knee hold it in place.
Collateral ligaments:The collateral ligaments include the MCL and LCL.
MCL injuries are common in sports.
Outside hits to the knee can injure the MCL.
In contrast, hits to the knee’s inside aspect injure the LCL and are less common.
Cruciate ligaments:The cruciate ligaments include the ACL and PCL.
Car crashes are a common cause of PCL tears.
You may hear a popping sound when any of these ligaments are initially injured.
Other symptoms may include pain and difficulty moving the knee.
Treatment for ligament tears often includes a combination of immobilization, pain management, and physical therapy.
Surgical interventions may be necessary depending on the severity of the tear.
Osteonecrosis
Osteonecrosis pops up if the blood supply to a bone in the body is disrupted.
When it occurs in the knee, it is known as osteonecrosis of the knee.
The knee joint becomes damaged without a healthy blood supply, and arthritis can occur.
Treatment for less severe cases includes pain management and limiting the use of the knee.
However, surgical interventions are often required, especially as the condition progresses.
Properly warming up before a workout, cooling down, and stretching can also help prevent knee injury.
When to See a Healthcare Provider
Knee popping is not necessarily a cause for concern.
Doing so may prevent a more serious knee injury.
Even if the knee popping isn’t painful, you may still want to have it checked out.
Sometimes, it may be an early sign of an overuse injury or osteoarthritis.
Weight loss, a change of footwear, or knee-strengthening exercises may fix the condition or help ease symptoms.
Summary
Knee popping or snapping can be harmless or a normal consequence of aging joints.
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