What Is a Bone Spur in the Knee?

Bone spurs, also called osteophytes, are outgrowths of bone that develop within joints due to increased pressure between bones from lack of cartilage. Bone spurs within the knee can cause pain and limit joint mobility, which can cause difficulty with everyday activities like walking, squatting, bending, and going up and down stairs, and can lead to muscle imbalances in the leg. However, not everyone will experience symptoms, and some may not know they have a bone spur in their knee. Osteophytes commonly occur in people with osteoarthritis, also known as degenerative joint disease, which causes a breakdown of cartilage.

knee pain

Virojt Changyencham / Getty Images

How Do Bone Spurs Form?

Without adequate cartilage around the knee joint, the bones of the knee become irritated and inflamed due to the increased pressure and friction within the joint during movement and weight-bearing of the leg as the bones rub against each other. Bone cells react to this increased pressure by producing more bone growth in an attempt to provide more protection to the joint, forming bone spurs that can change the appearance of the joint and limit mobility by restricting movement.

Signs of Bone Spurs in Knee

Osteophytes begin to cause symptoms when they put pressure on nearby nerves, restrict movement, and rub against other bones or tissues.

Symptoms associated with bone spur formation in the knee include:

  • Knobby or bumpy areas
  • Numbness and weakness
  • Pain near the knee
  • Reduced range of motion
  • Stiffness
  • Tendinitis

Bone spurs are often asymptomatic, and you will not know you have one until you have X-rays taken of your knees.

Causes of Bone Spurs in Knee

The most common cause of loss of cartilage in the knee joint that can lead to the development of bone spurs is knee osteoarthritis, which affects more than 45% of Americans at some point in their lifetime.

Cartilage loss in the knee joint can also result from injury to the knee, including anterior cruciate ligament (ACL) ruptures, meniscus tears, and patellar (kneecap) dislocations that increase the risk of cartilage damage and knee osteoarthritis in the future. Anyone who overuses their joints, including athletes, military personnel, and those with physically demanding jobs, may be at an increased risk for developing osteoarthritis.

Bone spurs occur in osteoarthritis due to the increased pressure in the joints that results from damaged cartilage. Rheumatoid arthritis is an autoimmune condition that causes joint damage as a result of the body attacking its own joints, resulting in widespread systemic inflammation. Because of this, bone spurs do not typically develop in patients with rheumatoid arthritis as commonly as they do in patients with osteoarthritis. 

Diagnosis

Bone spurs can be diagnosed with X-rays, which can help your doctor clearly see extra bone growths around the knee joints. Your doctor will also perform a physical exam of your knees to examine your range of motion and ask you about your symptoms and medical history to help make a diagnosis. Your doctor may also order CT scans or MRIs to visualize any damaged ligaments and tendons.

Early diagnosis of knee osteoarthritis and the bone spurs that form as a result is important for managing symptoms and preventing disease progression and further cartilage and joint damage.

Complications

Bone spurs result from a lack of cartilage from osteoarthritis of the knee. If left untreated, osteoarthritis can progress to a severe level where standing and walking can become very challenging and painful. If knee osteoarthritis is severe, a total knee replacement surgery is commonly performed as a last resort.

People with knee osteoarthritis and resulting bone spur formation often have pain with activities and movement that require bending and standing on the leg with the affected knee. Because of the discomfort, it is common for people to avoid placing strain on the knee joint by compensating elsewhere in the body. As a result, the supporting muscles of the hips and thighs may begin to atrophy and lose their strength, which limits balance and leg stability.

Similar to how bone spurs form, subchondral bone cells that underlie the cartilage at the ends of the bones that make up the knee joint react to increased pressure from cartilage loss by producing more bone growth in an attempt to provide more protection to the joint. The damaged bone grows back thicker than before as the body tries to repair damage, similar to thickened scar tissue that develops after an injury. This results in abnormal thickening of the bone called subchondral bone sclerosis, which also increases the risk of further bone spur development.

Treatment

Bone spurs can be asymptomatic and many people are unaware that they have them until having X-ray imaging performed. If a bone spur does not cause symptoms, no treatment is necessary. 

Problematic bone spurs, on the other hand, can cause pain, inflammation, swelling, stiffness, and decreased range of motion within a joint. If a bone spur breaks off from the bone within your knee, it becomes a loose body that can float within the joint space and limit your ability to move your knee joint comfortably. 

Medication

Cortisone is an anti-inflammatory medication that can be injected into the knee joint to reduce pain, swelling, and inflammation. Cortisone injections are the most commonly used type of knee injections for treating knee pain from osteoarthritis. These injections are performed under local anesthesia, where you will be awake for the procedure but your knee will be numbed. The medication usually begins to work two to three days later.

These injections can help relieve pain and reduce symptoms between six weeks and six months after the procedure, although the injections are not effective for everyone. You will typically not be allowed to receive more than two or three injections per year.

Over-the-counter (OTC) pain-relieving medications such as acetaminophen (Tylenol) and ibuprofen (Advil) or anti-inflammatory medication like naproxen sodium (Aleve) can also help reduce knee pain, swelling, and inflammation in the knee joint.

OTC creams and ointments, especially those that contain capsaicin, an extract derived from chili peppers, can also be applied topically to the knee to help relieve pain by decreasing the intensity of pain signals sent along nerve pathways. Topical pain medication is a suitable alternative for people who cannot take oral pain-relievers by mouth, especially those who suffer from gastrointestinal issues.

Physical Therapy

Physical therapy plays an important role in decreasing the symptoms of bone spurs and preventing progression of cartilage loss in the knees. A physical therapist will evaluate your knee and hip alignment, muscle strength, range of motion, and movement patterns to develop an individualized plan of care to address your limitations. 

The muscles surrounding the knee help support the knee joint. When they are weakened, the bones of the knee joint are subject to increased pressure and increased risk of cartilage breakdown, which leads to the development of bone spurs. Strengthening the muscles around the knees and hips helps offload the knee joint and support your body weight so that less pressure is applied to the joint surfaces.

Surgery

Knee arthroscopy is the most common type of surgical procedure performed to remove bone spurs and repair damaged cartilage in the knee joint. During the procedure, a surgeon uses an arthroscope, a tool about the width of a pencil with a camera and light attached, to view the inside of your knee joint. This allows the surgeon to examine the inside of the knee joint without making a large incision along the outside of the knee which is performed with open knee surgery.

Knee arthroscopy helps protect the knee joint from the risk of infection due to decreased exposure of the joint to the outside environment and often results in an improved cosmetic appearance of the knee by reducing the size of the surgical incisions and resulting scar formation. Knee arthroscopy also protects the surrounding knee structures, including skin, muscle, tendons, and ligaments from being damaged due to the smaller incisions. If significant osteoarthritis is already present, however, knee arthroscopy is typically not helpful for long-term relief of pain.

Bone spurs can be surgically removed through other types of procedures as well, including microfracture surgery, autologous chondrocyte implantation, and osteochondral autograft transplantation.

Pain Management

Ongoing knee pain and disability from bone spurs of the knee from osteoarthritis and cartilage loss can be frustrating, but there are ways that you can help manage your pain. Maintaining healthy lifestyle habits to decrease inflammation and stress to the joints can make it easier to manage symptoms and prevent worsening of bone and cartilage damage. These include:

  • Getting at least seven to eight hours of uninterrupted sleep at night
  • Eating a healthy diet of whole, natural foods
  • Maintaining a healthy weight and lean body mass through diet and exercise
  • Staying adequately hydrated
  • Maintaining a positive attitude and managing stress in healthy ways
  • Staying connected to others for social support
  • Resting your knee joints to decrease pain and inflammation
  • Limiting high impact and repetitive activities that stress the knee joint, such as running and jumping

A Word From Verywell 

Bone spurs in the knee develop from osteoarthritis and loss of cartilage in the knee joint that can progress to irreversible damage to the underlying bones. If you experience significant knee pain, stiffness, and decreased range of motion and strength, it is important to seek medical attention to manage your symptoms and prevent progression to further damage. 

Osteoarthritis is a degenerative condition that tends to get worse over time, but by taking care of your body and strengthening the muscles that support your knee, you can help prevent further damage to your knee joint and cartilage to stay active and pain-free.

Was this page helpful?
Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Shin CS, Lee JH. Arthroscopic treatment for osteoarthritic knee. Knee Surg Relat Res. 2012;24(4):187-192. doi: 10.5792/ksrr.2012.24.4.187

  2. Cleveland Clinic. Bone spurs (osteophytes). Updated November 16, 2020.

  3. Arthritis Foundation. Arthritis by the numbers: book of trusted facts and figures. Updated 2019.

  4. NYU Langone Health. Therapeutic injections for osteoarthritis of the knee

  5. Arthritis Foundation. NSAIDS.

  6. National Center for Biotechnology Information. PubChem compound summary for CID 1548943, capsaicin.

  7. American Academy of Orthopedic Surgeons. Knee arthroscopy. Updated September 2016.

  8. Sutter Health. Help for arthritic knees.