7 Rare Causes of Knee Pain

Article featured on Healthgrades

Knee Pain Without Injury

Injury, ongoing stress, and aging are the most common causes of knee pain. But what if none apply? One of several rare causes of knee pain may be at work, including benign tumors, fluid buildup, infection, certain types of arthritis and even genetic mutations. Many of these causes have the exact same symptoms but require very different treatments. It’s important to work with your doctor to arrive at an accurate diagnosis so you can not only start easing symptoms, but also prevent long-term damage to your knee joint.

1. Tenosynovial Giant Cell Tumor (TGCT)

TGCTs are non-cancerous tumors that grow around the knee joint. They can cause pain, swelling, and stiffness that affects your mobility and stability. Your knee may lock up at times, accompanied by a popping or creaking sound (crepitus). If you have symptoms of TGCT, talk with your doctor. Left untreated, TGCT can lead to osteoarthritis that may damage your knee joint and the surrounding cartilage and bones permanently. Treatment options can include surgery, radiotherapy, or targeted medication that works in the body on a cellular level to improve symptoms.

2. Synovial Chondromatosis

Like TGCT, synovial chondromatosis is non-cancerous and can also lead to osteoarthritis that causes damage if not treated. Symptoms are similar, too: knee pain, swelling, and difficulty with movement, sometimes with a popping sound. Unlike TGCT, synovial chondromatosis doesn’t involve tumors. It’s a condition that occurs when a membrane of the knee that lubricates the joint–the synovium–produces cartilage nodules that bump into and damage healthy, protective cartilage in the joint space. Depending on the size and volume of the nodules, either non-invasive or traditional surgery may be recommended.

3. Chondrocalcinosis 2 (CCAL2)

CCAL2 is a genetic disorder caused by a mutation in the ANKH gene. The mutated gene carries calcium crystals to the cartilage around the knee joint, which damages it. Symptoms can vary significantly. They may include knee pain, swelling, and impaired mobility like other knee conditions or they may feel more like sudden attacks of pain with redness and a warm feeling. CCAL2 can’t be cured, but many effective treatments are available to ease symptoms. They include procedures to drain fluid from the knee and medicines such as corticosteroids and nonsteroidal anti-inflammatory drugs (NSAIDs).

4. Pigmented Villonodular Synovitis

It’s not yet known what causes pigmented villonodular synovitis (PVNS), and the symptoms are similar to other knee conditions. When you have PVNS, the lining of your knee joint swells and grows, and fluid builds up. Your doctor may test fluid from your knee to diagnose the condition. Symptoms can come and go, so the first step may be resting your knee and taking nonprescription pain relievers. If symptoms are severe and persist over time, your doctor may recommend surgery to remove your knee joint lining. A non-invasive procedure may be an option.

5. Adult Still’s Disease

Adult Still’s disease is a type of inflammatory arthritis that can come with distinct symptoms in addition to knee pain: rash, fever, and sore throat. Your knee joint may also feel achy, and nearby muscles may hurt. It’s not known what causes Adult Still’s disease, but some research points to infection. The condition is usually treated with one or more of these medicines: NSAIDs; steroids; methotrexate; and biologic drugs that target your body’s inflammatory response at the cellular level.

6. Septic Arthritis

Septic arthritis is a joint infection, and the most common type is Staphylococcus aureus (staph). The infection can be caused by an injury such as a cut or animal bite or it can be introduced during surgery–but it’s usually caused by an infection that has traveled from another part of your body like your urinary tract or skin. Septic arthritis is painful, and it may come with swelling, redness, warmth, or fever. Treatment usually includes draining the fluid around the knee joint and taking antibiotics.

7. Reactive Arthritis

Like septic arthritis, reactive arthritis in the knee can also be caused by an infection that has travelled from another part of your body. The most common types are sexually transmitted infections (STIs) and food poisoning. Antibiotics are usually prescribed to cure the infection. Symptoms include pain and swelling, as well as irritation of the genitals or eyes. If you have any symptoms of a rare knee condition, try to write them down and note how long they last. Bring this information to your doctor’s appointment to inform the diagnosis and help speed your time to treatment.


The Orthopedic & Sports Medicine Center of Oregon is an award-winning, board-certified orthopedic group located in downtown Portland Oregon. We utilize both surgical and nonsurgical means to treat musculoskeletal trauma, spine diseases, sports injuries, degenerative diseases, infections, tumors and congenital disorders.

Our mission is to return our patients back to pain-free mobility and full strength as quickly and painlessly as possible using both surgical and non-surgical orthopedic procedures.

Our expert physicians provide leading-edge, comprehensive care in the diagnosis and treatment of orthopedic conditions, including total joint replacement and sports medicine. We apply the latest state-of-the-art techniques in order to return our patients to their active lifestyle.

If you’re looking for compassionate, expert orthopedic surgeons in Portland Oregon, contact OSM today.

Phone:
503-224-8399

Address
1515 NW 18th Ave, 3rd Floor
Portland, OR 97209

Hours
Monday–Friday

Patellar Tendinitis: Causes and Symptoms

Article featured on Mayo Clinic

Overview

Patellar tendinitis is an injury to the tendon connecting your kneecap (patella) to your shinbone. The patellar tendon works with the muscles at the front of your thigh to extend your knee so that you can kick, run and jump.

Patellar tendinitis, also known as jumper’s knee, is most common in athletes whose sports involve frequent jumping — such as basketball and volleyball. However, even people who don’t participate in jumping sports can get patellar tendinitis.

For most people, treatment of patellar tendinitis begins with physical therapy to stretch and strengthen the muscles around the knee.

Symptoms

Pain is the first symptom of patellar tendinitis, usually between your kneecap and where the tendon attaches to your shinbone (tibia).

Initially, you may only feel pain in your knee as you begin physical activity or just after an intense workout. Over time, the pain worsens and starts to interfere with playing your sport. Eventually, the pain interferes with daily movements such as climbing stairs or rising from a chair.

When to see a doctor

For knee pain, try self-care measures first, such as icing the area and temporarily reducing or avoiding activities that trigger your symptoms.

Call your doctor if your pain:

  • Continues or worsens
  • Interferes with your ability to perform routine daily activities
  • Is associated with swelling or redness about the joint

Causes

Patellar tendinitis is a common overuse injury, caused by repeated stress on your patellar tendon. The stress results in tiny tears in the tendon, which your body attempts to repair.

But as the tears in the tendon multiply, they cause pain from inflammation and weakening of the tendon. When this tendon damage persists for more than a few weeks, it’s called tendinopathy.

Risk factors

A combination of factors may contribute to the development of patellar tendinitis, including:

  • Physical activity. Running and jumping are most commonly associated with patellar tendinitis. Sudden increases in how hard or how often you engage in the activity also add stress to the tendon, as can changing your running shoes.
  • Tight leg muscles. Tight thigh muscles (quadriceps) and hamstrings, which run up the back of your thighs, can increase strain on your patellar tendon.
  • Muscular imbalance. If some muscles in your legs are much stronger than others, the stronger muscles could pull harder on your patellar tendon. This uneven pull could cause tendinitis.
  • Chronic illness. Some illnesses disrupt blood flow to the knee, which weakens the tendon. Examples include kidney failure, autoimmune diseases such as lupus or rheumatoid arthritis and metabolic diseases such as diabetes.

Complications

If you try to work through your pain, ignoring your body’s warning signs, you could cause increasingly larger tears in the patellar tendon. Knee pain and reduced function can persist if you don’t tend to the problem, and you may progress to the more serious patellar tendinopathy.

Prevention

To reduce your risk of developing patellar tendinitis, take these steps:

  • Don’t play through pain. As soon as you notice exercise-related knee pain, ice the area and rest. Until your knee is pain-free, avoid activities that put stress on your patellar tendon.
  • Strengthen your muscles. Strong thigh muscles are better able to handle the stresses that can cause patellar tendinitis. Eccentric exercises, which involve lowering your leg very slowly after extending your knee, are particularly helpful.
  • Improve your technique. To be sure you’re using your body correctly, consider taking lessons or getting professional instructions when starting a new sport or using exercise equipment.

The Orthopedic & Sports Medicine Center of Oregon is an award-winning, board-certified orthopedic group located in downtown Portland Oregon. We utilize both surgical and nonsurgical means to treat musculoskeletal trauma, spine diseases, sports injuries, degenerative diseases, infections, tumors and congenital disorders.

Our mission is to return our patients back to pain-free mobility and full strength as quickly and painlessly as possible using both surgical and non-surgical orthopedic procedures.

Our expert physicians provide leading-edge, comprehensive care in the diagnosis and treatment of orthopedic conditions, including total joint replacement and sports medicine. We apply the latest state-of-the-art techniques in order to return our patients to their active lifestyle.

If you’re looking for compassionate, expert orthopedic surgeons in Portland Oregon, contact OSM today.

Phone:
503-224-8399

Address
1515 NW 18th Ave, 3rd Floor
Portland, OR 97209

Hours
Monday–Friday

Knee Hyperextension: What is it?

Article featured on News Medical Life Sciences

Knee hyperextension is a condition caused when the knee straightens too far, beyond the normal maximum limit of 00 and often with the joint in varus malalignment. In the properly aligned knee, the load is borne on a line running down the center of the hip, knee and ankle, but in a varus deformity (bowleg form), the line is shifted outwards and back.

The most common injuries are posterolateral joint injury and avulsion of the bone attached to the anterior cruciate ligament, and they are especially common in young children due to their softer bones. Posterior cruciate ligament, however, is rare.

Causes

Knee hyperextension may occur because of:

  • Trauma caused by impact to the front of the knee, which makes the joint move backward, putting high strain on the anterior cruciate ligament – such as when a football player faces a leg tackle.
  • Pushing the femur or patella over the tibia, the lower leg bone, for example when one slides to a sudden stop using one leg, which stresses the major ligaments within the knee.
  • Genu recurvatum: this is a deformity characterized by knee hyperextension over 5 degrees.
  • Nerve damage, such as Brain injury (congenital, stroke-induced or traumatic), or poliomyelitis, may cause hyperextended gait because of muscle (quadriceps or calf muscle) atrophy, spastic plantar flexion of the ankle, or contractures of the heel tendons.

Symptoms

The cause of hyperextension predicts the symptoms, which may be minor pain and swelling when it occurs to a trivial degree, but may consist of sharp pain, strained or torn cruciate ligaments, avulsion of bone chips accompanying such tears, and bone bruising may occur on the anterior part of the knee joint. When the injury is at the posterolateral aspect, the ACL and the PCL typically tears. The rate of strain doesn’t seem to be the major factor as anterior cruciate ligaments tears vary at all rates of strain. Genu recurvatum may present with knee pain, abnormal gait, and a lack of proprioceptive perception, which makes it difficult to tell when the terminal extension of the knee is attained.

The hyperextended knee gait is marked by various degrees of abnormality. In some, the patient can walk only with the aid of a cane or a crutch. In others with minimal weakness, the knee becomes hyperextended only when the patient walks too much or indulges in other heavy work or exercise, leading to muscle fatigue and loss of joint support. The associated ligamentary and muscle weakness and joint integrity also contribute to the final abnormality of gait, as does the presence of arthritis in the knee joint.

Another symptom is knee instability, or a feeling of giving way at the knee, in part or full, during normal activities.

Pain may be felt over the knee or to the medial side, and is caused by compression of the soft tissues by the malaligned knee, as well as on the posterolateral aspect, due to stretching of the soft tissue. In acute hyperextension injury the knee may pop and acute swelling often occurs within a few hours of the injury. The pain can become too severe for normal support of weight during walking or running.

Anatomy

The knee joint is supported on the lateral and posterior aspects by the fibular collateral ligament, and the popliteus muscle with its tendon and ligament. This complex of structures keeps the knee compartment from widening laterally, prevents dislocation of the lateral surface of the tibial component of the knee to the back, keeps the tibia from rotating, and thus prevents both knee hyperextension and genu recurvatum. The bones may show varus alignment, in some cases. A triple varus knee is caused by three factors:

  • Tibiofemoral alignment is disturbed.
  • The lateral tibiofemoral compartment separation is increased because of weak supporting structures on the posterolateral aspect of the knee.
  • The knee appears bowlegged in skeletal outline when fully extended.

In most cases both the posterolateral structures and the anterior cruciate ligament is damaged or at least weak, as following a knee injury or any other cause of muscle atrophy. Patellofemoral arthritis is another cause, but in this case the hyperextended knee gait is due to pain as well as muscle weakness.

Diagnosis

The history will offer clues to the diagnosis, such as prior knee injury. A physical examination will help confirm and grade the injury, including joint mobility, visible injury, bruising or swelling, and locking of the joint. Imaging is needed in severe injury and especially if surgery is contemplated. MRI and X-ray imaging are typically performed.

Treatment

Minor hyperextension of the knee may require only the R.I.C.E approach:

  • Rest and avoidance of physical activities that strain the knee in any way for a few weeks.
  • Ice application several times a day.
  • Compression using a knee brace and crutches for support are helpful in protecting the ligaments of the knee against any further damage.
  • Elevation to reduce edema.

Severe cases will require physical therapy, with graded exercises of the quadriceps and other hip and knee muscles. This should be done under supervision so that further injury does not occur, and full joint mobility is attained. Surgery is required to reattach torn ligaments and will again be followed by physical therapy.

Correction of the hyperextended knee gait is crucial if the deformity is to be corrected permanently, otherwise the excessive tensile force on the ligaments inside the joint and increased muscle force could increase the load on the joint capsules, especially the medial and lateral compartments. This can be harmful to joint integrity in varus malalignment.


The Orthopedic & Sports Medicine Center of Oregon is an award-winning, board-certified orthopedic group located in downtown Portland Oregon. We utilize both surgical and nonsurgical means to treat musculoskeletal trauma, spine diseases, sports injuries, degenerative diseases, infections, tumors and congenital disorders.

Our mission is to return our patients back to pain-free mobility and full strength as quickly and painlessly as possible using both surgical and non-surgical orthopedic procedures.

Our expert physicians provide leading-edge, comprehensive care in the diagnosis and treatment of orthopedic conditions, including total joint replacement and sports medicine. We apply the latest state-of-the-art techniques in order to return our patients to their active lifestyle.

If you’re looking for compassionate, expert orthopedic surgeons in Portland Oregon, contact OSM today.

Phone:
503-224-8399

Address
1515 NW 18th Ave, 3rd Floor
Portland, OR 97209

Hours
Monday–Friday

Swollen Knee Causes and Treatments

Article featured on the Mayo Clinic

Overview

A swollen knee occurs when excess fluid accumulates in or around your knee joint. Your doctor might refer to this condition as an effusion (ih-FYU-zhen) in your knee joint. Some people call this condition “water on the knee.”

A swollen knee may be the result of trauma, overuse injuries, or an underlying disease or condition. To determine the cause of the swelling, your doctor might need to obtain a sample of the fluid to test for infection, disease or injury.

Removing some of the fluid also helps reduce the pain and stiffness associated with the swelling. Once your doctor determines the underlying cause of your swollen knee, appropriate treatment can begin.

Symptoms

Signs and symptoms typically include:

  • Swelling. The skin around your kneecap can puff up noticeably, especially when you compare the affected knee to the normal one.
  • Stiffness. When your knee joint contains excess fluid, you might not be able to bend or straighten your leg completely.
  • Pain. Depending on the cause of the fluid buildup, the knee might be very painful — to the point that it’s difficult or impossible to bear weight on it.

When to see a doctor

See your doctor if:

  • Self-care measures or prescribed medications don’t relieve the pain and swelling
  • One knee becomes red and feels warm to the touch compared to your other knee

Causes

Many types of problems, ranging from traumatic injuries to diseases and other conditions, can cause a swollen knee.

Injuries

Damage to any part of your knee can cause excess joint fluid to accumulate. Injuries that can cause fluid buildup in and around the knee joint include:

  • Torn ligament, particularly the anterior cruciate ligament (ACL)
  • Cartilage (meniscus) tear
  • Irritation from overuse
  • Broken bones

Diseases and conditions

Underlying diseases and conditions that can produce fluid buildup in and around the knee joint include:

  • Osteoarthritis
  • Rheumatoid arthritis
  • Infection
  • Gout
  • Pseudogout
  • Bursitis
  • Cysts
  • Tumors

Risk factors

  • Age. Your likelihood of developing a swollen knee related to arthritis increases as you age.
  • Sports. People who participate in sports that involve twisting the knee, such as basketball, are more likely to experience the types of knee injuries that cause swelling.
  • Obesity. Excess weight puts added stress on the knee joint, contributing to the tissue and joint overload and knee degeneration that can lead to a swollen knee. Obesity increases your risk of osteoarthritis, one of the more frequent causes of knee swelling.

Complications

Complications of a swollen knee can include:

  • Muscle loss. Fluid in the knee can harm the working of your muscles and cause thigh muscles to weaken and atrophy.
  • Fluid-filled sac (Baker’s cyst). The buildup of fluid in your knee can lead to the formation of a Baker’s cyst in the back of your knee. A swollen Baker’s cyst can be painful, but usually improves with icing and compression. If the swelling is severe, you might need to have fluid removed (cyst aspiration).

Prevention

A swollen knee is typically the result of an injury or chronic health condition. To manage your overall health and prevent injuries:

  • Strengthen the muscles around your knee. Strong muscles around a joint can help ease pressure on the joint itself.
  • Choose low-impact exercise. Certain activities, such as water aerobics and swimming, don’t place continuous weight-bearing stress on your knee joints.
  • Maintain a healthy weight. Excess weight contributes to the wear-and-tear damage that can lead to a swollen knee.

The Orthopedic & Sports Medicine Center of Oregon is an award-winning, board-certified orthopedic group located in downtown Portland Oregon. We utilize both surgical and nonsurgical means to treat musculoskeletal trauma, spine diseases, sports injuries, degenerative diseases, infections, tumors and congenital disorders.

Our mission is to return our patients back to pain-free mobility and full strength as quickly and painlessly as possible using both surgical and non-surgical orthopedic procedures.

Our expert physicians provide leading-edge, comprehensive care in the diagnosis and treatment of orthopedic conditions, including total joint replacement and sports medicine. We apply the latest state-of-the-art techniques in order to return our patients to their active lifestyle.

If you’re looking for compassionate, expert orthopedic surgeons in Portland Oregon, contact OSM today.

Phone:
503-224-8399

Address
1515 NW 18th Ave, 3rd Floor
Portland, OR 97209

Hours
Monday–Friday
8:00am – 4:30pm

Why Do My Knees Pop?

Article featured on Cone Health Medical Group

Have you ever bent down to pick up something and heard a loud pop or crack coming from your knees? This sound is called “crepitus,” which is defined as “joint noise.” Popping knees are not unusual. It happens when carbon dioxide builds up in the joint’s synovial fluid and is released as a gas bubble that bursts when the joint adjusts rapidly. It is the same process that causes knuckles to crack.

Most of the time, this noise should cause no concern. There has been a rumor circulating for years that popping joints are a sign of impending arthritis, but there has been no research that supports this.

Some folks may hear a grinding noise in the knee when they squat. This is another form of crepitus and is typically nothing to be concerned about. The sound is caused by the cartilage rubbing on the joint surface and other soft tissue when the knee moves.

Most people experience crepitus their entire lives with no problems.

What if it hurts when my joints pop or grind?

You should be concerned if you have joint noise that is accompanied by pain, discomfort or swelling. This could be a sign that medical attention is required. Two of the most common cause for knee pain are:

  1. Cartilage injury or wear. The underside of your kneecap can unevenly rub on the front of your femur (thigh bone) and cause the cartilage under your kneecap to soften and wear off. Once the cartilage wears off, it hangs around the joint and can irritate the surrounding area. This irritation can result in pain when squatting, climbing stairs or even sitting for an extended period.
  2. Meniscus tear. The rubbery disc that cushions your knee and absorbs shock is called the meniscus. It can tear when there is an unexpected twist or turn in the joint, usually when the knee moves and the foot stays stationary. With aging comes greater risk of a meniscus tear, even through everyday activities.

What are the treatment options for knee injuries?

  • Rest – Stay off your knee as much as possible.
  • R.I.C.E. – Rest, ice, compression and elevation will promote healing and reduce swelling.
  • Knee Brace – There are many kinds, so it is best to consult your care provider for advice.
  • Physical therapy – A physical therapist can help you learn techniques and exercises to strengthen your knee and allow it time to heal.
  • Surgery – Minimally invasive surgery, especially for meniscus tears, can repair the tear and clear out any tissue causing pain, swelling and irritation.  

To help protect the knees, try exercises that develop the quadriceps, which are the muscles in the front of the thigh. Exercises that benefit this muscle group are walking, cycling and swimming. Other effective ways of protecting the knees are wearing supportive shoes, warming up before and stretching after exercise, and maintaining a healthy body weight.


The Orthopedic & Sports Medicine Center of Oregon is an award-winning, board-certified orthopedic group located in downtown Portland Oregon. We utilize both surgical and nonsurgical means to treat musculoskeletal trauma, spine diseases, sports injuries, degenerative diseases, infections, tumors and congenital disorders.

Our mission is to return our patients back to pain-free mobility and full strength as quickly and painlessly as possible using both surgical and non-surgical orthopedic procedures.

Our expert physicians provide leading-edge, comprehensive care in the diagnosis and treatment of orthopedic conditions, including total joint replacement and sports medicine. We apply the latest state-of-the-art techniques in order to return our patients to their active lifestyle.

If you’re looking for compassionate, expert orthopedic surgeons in Portland Oregon, contact OSM today.

Phone:
503-224-8399

Address
1515 NW 18th Ave, 3rd Floor
Portland, OR 97209

Hours
Monday–Friday
8:00am – 4:30pm

Answers to Common Questions About Knee Replacement Surgery

Article Featured on WebMD

Who Needs Knee Replacement Surgery?

You and your doctor may consider knee replacement surgery if you have a stiff, painful knee that makes it difficult to perform even the simplest of activities, and other treatments are no longer working. Historically, this surgery has generally been reserved for people over age 50 who have severe osteoarthritis but with advances in technology, adults are more frequently opting for earlier surgeries to optimize their quality of life.

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12 Tips for Walking When You Have Sensitive Knees

From VeryWellFit

Sensitive knees can be a challenge for walking, but it is a recommended way to maintain your function and reduce your symptoms. If you have knee pain due to osteoarthritis or other causes, you don’t have to let that keep you from starting a walking program.

A regular program of walking can reduce stiffness and inflammation and it won’t make most chronic knee conditions worse. Walking is the preferred exercise by people with arthritis, and can help you improve your arthritis symptoms, walking speed, and quality of life, according to the CDC.

Walking is part of a healthy lifestyle to keep your heart and bones strong and your joints functioning. Here are tips for walking when you have sensitive knees.

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How can you tell if you have a torn meniscus?

How can you tell if you have a torn meniscus?

Article Featured on WebMD

Like a lot of knee injuries, a meniscus tear can be painful and debilitating. Unfortunately, it’s quite common. In fact, a meniscal tear is one of the most frequently occurring cartilage injuries of the knee. So how can you tell if you have one? Learn more in this article.
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Six Tips to Keep Your Knees & Joints Healthy

Six Tips to Keep Your Knees & Joints Healthy

by Stacey Colino, AARP

If you’ve walked, jogged and hiked this far without any major knee trouble, there’s more you can do than thank your lucky stars. A few basic steps can help you protect your knees as you age.

Besides being the largest joint in the human body, “the knees are unique in that the motion involved is very complex,” says Sanjeev Bhatia, an orthopedic sports medicine surgeon and codirector of the Northwestern Medicine Hip and Knee Joint Preservation Center at Central DuPage Hospital in Winfield, Illinois. “The knee has three compartments, any of which can cause pain with wear and tear.”

With the passage of time, a certain amount of wear and tear on your joints is inevitable. But it doesn’t have to affect the way your knees feel, function or move. If you experience a clicking or popping sensation in the joint when you walk, bend or lunge, but there’s no pain or swelling, you don’t need to worry about it, says Dennis Cardone, D.O., an associate professor of orthopedic surgery and sports medicine at NYU Langone Health in New York City. On the other hand, if you have pain or swelling with that clicking or popping, it’s best to schedule a visit to your doctor.

Otherwise, to minimize your risk of experiencing pain, stiffness and inflammation in your knees, take these steps to protect these essential joints.

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Why Knee Pain Could Be a Thing of the Past

Why Knee Pain Could Be a Thing of the Past

By David C. Flanigan, M.D. | Article Featured on US News

AS WE AGE, WE’RE MORE prone to experience joint pain, but knee aches and pains might be the result of a bigger culprit: osteoarthritis. As the most common chronic joint condition, about 31 million Americans are diagnosed with knee osteoarthritis in their lives. This occurs when cartilage in the joint wears away, and it causes stiffness and swelling that worsens over time.

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