Bone spurs in the knee are a common problem, particularly in people over the age of 60.
In some cases, knee bone spurs cause no symptoms at all, but for other people, they may result in both pain and stiffness and can really affect daily life.
Bone spurs are hard, bony lumps that grow on the surface of joints through a process called osteophytosis, forming bumps or ridges. In some cases, bone spurs cause no symptoms at all, but if they start to rub against other bones or soft tissues, they may result in both pain and stiffness and can really affect daily life.
Bone spurs on the knee are usually caused by cartilage damage, arthritis and excess pressure through the joint.
Here we will look at what bone spurs in the knee are, how they form, the common causes and symptoms, how they are diagnosed and the best treatment options for knee bone spurs.
Knee bone spurs, also called osteophytes, are small, hard lumps of excess bone that grow and project into the knee joint. They typically develop when there is excessive pressure on the knee bones from a lack of cartilage.
The knee joint is the meeting point between the thigh bone (femur) and the skin bone (tibia). It is a hinge joint that allows you to bend and straighten your leg.
In the middle of the “hinge” is a cushioning material called cartilage that covers the ends of the two bones.
There is also another extra thick layer of cartilage on top of the tibia, known as the meniscus.
The knee cartilage acts like a shock absorber and helps the bones to move smoothly against each other without any friction.
If the knee cartilage gets damaged or is put under too much pressure or friction, then the knee bones get irritated and inflamed as they rub against each other. The knee joint starts laying down new bone, a natural process known as osteogenesis, to try and protect itself and repair the damaged areas. If this goes into overdrive, it causes bone spurs in the knee to form.
Knee bone spur formation goes through a few stages:
Bone spurs in the knee usually grow slowly, forming over a few months or even years. The exact rate of growth can vary significantly among individuals, depending on factors such as the underlying cause, the extent of joint damage and the body’s response to the condition.
Bone growth with knee osteophytosis doesn’t tend to be steady or constant. This means the excess bone doesn’t usually grow at a uniform rate and the progression of knee spurs is often influenced by the underlying cause. There may be periods where the knee osteophytes develop rapidly, or in other cases their growth may slow down or stop altogether. Often, knee spurs reach a certain size and then remain relatively stable without significant further growth for an extended period, maybe even forever.
Bone spurs in the knee usually form in response to stress, pressure or damage to the knee joint cartilage and they are typically caused by:
The most common cause of a bone spur on the knee is osteoarthritis, a type of degenerative joint disease.
Knee osteoarthritis causes wear and tear of the joint over time and the knee cartilage gradually breaks down. As the body tries to repair the damaged cartilage, it creates new bone material which over time builds up, forming knee spurs.
It is worth noting that while osteoarthritis is the most common cause of knee spurs, not all types of arthritis lead to bone spurs in the knee. For example, rheumatoid arthritis is an autoimmune condition where the body's immune system mistakenly attacks its own joints. This leads to joint damage and widespread inflammation throughout the body but isn’t as likely to cause bone spurs on the knee as osteoarthritis.
You can find out all about the causes, symptoms, diagnosis and treatment options in the Knee Arthritis section.
If you have injured your knee in the past, you may be at increased risk of developing bone spurs in the knee in the future. Common knee injuries that increase the risk of knee osteophyte formation include:
Cartilage naturally deteriorates with age, becoming less elastic and less flexible. It loses water content making it less plump, and collagen fibres become less organised. This all causes the cartilage to become stiffer and more brittle, making it more prone to wear and tear and degeneration, increasing the risk of bone spurs forming in the knee.
Certain occupations or activities that involve repetitive stress on the knee joint, such as kneeling, squatting, or running, can increase the likelihood of developing knee spurs. This is common in athletes, manual laborers and military personnel. The continuous pressure and strain on the knee can lead to the formation of bony outgrowths.
A bone spur under the knee is often caused by muscle tightness. The most common example of this is tightness in the quadriceps muscles.
The quads attach to the front of the shin bone at the tibial tuberosity, just below the knee, via the patellar tendon. If there is tightness in the quads muscles, it pulls on the tendon’s attachment point.
This creates a lot of tension on the bone, causing damage and inflammation, resulting in a condition called Osgood Schlatters Disease. Excess bone is laid down, resulting in a hard bump below the knee. Osgood Schlatters is the most common cause of a bone spur in the knee in teenagers, and often develops just after a growth spurt.
There are a few other things that can cause bone spurs in the knee to form such as
In many cases, knee osteophytes are small and don’t actually cause any symptoms (asymptomatic) - people are often completely unaware they have bone spurs in their knees until they show up on an x-ray. But if the knee spur gets large enough that it starts encroaching on other structures, then it can cause problems.
Bone spur knee symptoms typically include:
Knee bone spurs can increase the risk of developing other knee problems such as:
The diagnosis of knee bone spurs is usually made by your doctor and typically involves a combination of taking a thorough medical history, a physical examination, and imaging studies.
Early diagnosis of bone spurs in the knee is crucial for being able to effectively manage symptoms, prevent disease progression and minimise additional cartilage and joint damage.
Treatment for knee bone spurs aims to relieve symptoms, improve joint function, and address the underlying causes of the knee spurs. The specific treatment approach will vary depending on the severity of symptoms and individual circumstances.
Knee bone spurs treatment is only necessary if you are experiencing symptoms such as pain or restricted mobility.
In many cases, bones spurs in the knee can be treated without the need for surgery, known as conservative treatment. Common bone spur knee treatment includes:
Over-the-counter painkillers, e.g. paracetamol/Acetaminophen and non-steroidal anti-inflammatory drugs (NSAIDs) e.g. ibuprofen/Advil can help reduce the pain and inflammation associated with knee bone spurs. Your doctor may prescribe stronger pain medications if necessary - always check with your doctor before starting any new medications.
Physical therapy is an important part of bone spur knee treatment and can help to not only relieve pain and improve range of motion, but can also slow down the progression of cartilage damage and knee spur growth.
Your doctor may advise trying knee injections as part of your knee bone spur treatment to reduce pain and inflammation. There are two options for knee injections:
Corticosteroid Injections: Injecting a mixture of anaesthetic and steroid directly into the knee joint can provide temporary relief from pain and inflammation. The effects may be felt for anything from a few days, to weeks or even months in some cases.
Hyaluronic Acid Injections: These injections, also known as visco-supplementation, involve injecting a gel-like substance into the knee joint to improve lubrication and reduce friction. Synvisc is a common brand used.
The use of assistive devices like knee braces, orthotics, or shoe inserts can really help alleviate pressure on the affected knee joint and provide support during activities to reduce pain from spurs on the knee and improve function
Maintaining a healthy weight, adopting low-impact exercises e.g. cycling or swimming rather than running, and avoiding activities that exacerbate symptoms can help manage knee bone spur-related discomfort.
If your bone spurs in the knee are linked with osteoarthritis, there are a lot of other treatments that can help including acupuncture, natural remedies, walking aids, knee pads and rehab programs. You can find out all about them in the knee arthritis treatment section.
In some cases, bone spur knee surgery may be advised if you have failed to respond to non-surgical treatment or if the knee spurs are causing significant disability.
There are a two options when it comes to bone spur in knee surgery, depending on the extent of the joint damage:
Arthroscopic knee bone spur removal surgery, aka keyhole or minimally invasive surgery, may be performed to remove or trim the bone spurs and smooth out damaged cartilage. A knee arthroscopy is the most common type of bone spur knee surgery performed and has good success rates.
In severe cases where the joint damage is extensive, joint replacement surgery may be considered, with the damaged joint being replaced with an artificial joint.
Knee joint replacements are typically recommended for knee bones spurs associated with severe knee arthritis that has failed to respond to other treatment methods.
Depending on how much of the knee is damaged you may need one or both sides of the knee replacing. You can find out all about the different types of knee replacements, what happens and the recovery process in the knee replacement section.
The choice of bone spur knee treatment depends on factors such as the severity of symptoms, the impact on daily activities, overall health, and individual preferences.
Knee bone spurs are a common problem, where excess bone grows, forming hard lumps, usually due to cartilage damage.
In many cases, bone spurs on the knee do not cause any obvious symptoms and often go undetected.
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Page Last Updated: 06/02/24
Next Review Due: 06/02/26