Chronic Knee Pain: 10 Possible Causes

What is Chronic Knee Pain?

Chronic knee pain occurs in one or both knees and lasts long after the initial injury. It is a long-term pain that is often accompanied by swelling or sensitivity. Many factors contribute to the development of chronic knee pain and can affect people of all ages.

What are the symptoms of chronic knee pain?

The symptoms of chronic knee pain vary from person to person. Some people experience pain directly after an injury, while others may notice a delayed onset of symptoms. Symptoms include sharp pain, a dull non-specific pain that is hard to locate, stiffness, swelling, weakness, and instability.

What causes chronic knee pain?

Unlike acute or temporary knee pain, chronic pain is defined as pain that lasts longer than three months, and it is often caused by tendinitis, arthritis or ligament injuries. Chronic knee pain seldom resolves without treatment, and it can be challenging to determine what caused the pain without a proper medical diagnosis.

Common causes of chronic knee pain

1. Tendinopathy

Tendinopathy is characterised by pain or swelling above or below the kneecap that recurs with specific activities and dissipates with rest.

2. Arthritis

Arthritis usually develops from 'wear and tear'; causing stiffness and pain. The knee joint becomes inflamed and swollen and may be debilitating or long-lasting.[1]30331-X/fulltext)

3. Myofascial pain

Chronic knee pain occurs because of problems with the knee's surrounding muscles, ligaments, and tendons. The muscles sometimes develop trigger points or knots known as myofascial pain, which can be painful and incapacitating.

4. Ligament injuries

Ligament injuries are defined as strains, sprains or tears in the ligaments that support the knee. Many ligament tears are caused by quickly changing direction, twisting, and landing awkwardly from a jump. Sports such as soccer, basketball, rugby, and tennis are common causes of this type of injury.

5. Bursitis

Bursitis causes inflammation, often occuring in the small fluid-filled sacs that cushion the knee cap.

6. Meniscal injuries

The meniscus is the cartilage deep within the knee joint that acts as a shock absorber. Meniscal tears sometimes occur when the knee is forcefully twisted.

7. Chondromalacia patella

This condition is caused by damage or wear and tear of the cartilage under the kneecap.

8. Patellar tendonitis

Patellar tendonitis is cahracterised by pain, swelling or inflammation in the tendon below the knee cap. It is often the result of a kneecap dislocation or an overuse injury.

9. Gout

Gout occurs with a build-up of uric acid, which causes the formation of tiny crystals in the joint. It is often swollen and painful and limits the use of the knee.

10. Bone tumours

While less common, cancers such as osteosarcoma can affect the knee.

Many other factors increase your chances of knee pain and what type of pain you may experience.[3] These include:

• Age - Younger people will likely develop knee pain due to a direct injury to the knee. In comparison, older people may develop knee pain from degeneration or deterioration of the joint.

• Activity level - Active people are more likely to develop ligament, tendinous, or cartilaginous injuries.

• Previous injury of the knee - Previous injuries that were not adequately treated may recur later and cause chronic pain.

• Obesity - A weight-bearing joint, the knee takes significant strain when you gain extra weight. The knee absorbs approximately four additional kilograms for each kilogram you gain.

How is Chronic Knee Pain Diagnosed?

To diagnose chronic knee pain, your physiotherapist or doctor will require a detailed history of the pain and perform a physical exam. The exact nature and cause of the pain will have to be established. The physical exam requires exposing the knee joint (if possible, wear shorts to your appointment) and inspecting the knee for swelling and inflammation. The examiner may also move your knee in different directions to stress the ligaments, tendons, and cartilage to evaluate their integrity.

The physical examination may consist of several assessments including, but not limited to:

• Gait (walking) analysis - Your doctor or physiotherapist is trained to detect any changes in the movement of the knee during the different phases of walking.

• Palpation - The examiner will palpate (or touch) your knee to assess whether different structures are sensitive and assess abnormalities in the structure of the knee.

• Strength - The examiner will assess your knee for weakness and assess whether muscular weakness or muscle imbalances are causing pain in your knee.

• Range of motion (ROM) - The ROM determines how far the knee can bend or straighten. Special instruments may be used to measure if there are limitations in the movement of the knee, which will help direct the treatment.

• Special tests - These are manoeuvres performed around the knee that strain particular ligaments, tendons, and cartilage to help identify which structure is causing the knee pain.

Sometimes further investigation may be required, including X-rays, CT scans, ultrasound scans, Magnetic Resonance Imaging (MRI), and even blood tests. The nature of the injury and accompanying symptoms will determine which test will be required.

Treating Chronic Knee Pain

Once the diagnosis has been confirmed, treatment can begin. Treatment often involves using medications or injections to alleviate the pain, physiotherapy, and in more severe cases, surgery.

Conservative treatment, such as physiotherapy, is always a good place to start with treating chronic knee pain. Physiotherapy management for chronic knee pain aims to relieve pain, restoring range of motion and strength.[2] Common interventions for the treatment of chronic knee pain include:

• RICE - Rest, Ice, Compress, and Elevate the knee if it is very swollen and painful (although this treatment is usually directly after an injury has occurred).

• Manual therapy - Mobilising the knee joint and releasing any tightness in the surrounding muscles.

• Strengthening - Particularly the quadriceps (or thigh) and gluteal (buttock) muscles to help stabilise the knee and keep it aligned.

• Taping - Prevents the kneecap from rubbing on the underlying femur (thigh bone).

• Orthotics - (or shoe inserts) Help with the positioning of the foot during walking and running.

• Electrotherapy - Aims to stimulate muscles that may increase the stability of the joint.

The goal of physiotherapy is always to restore pain-free functional mobility. However, the long-term management of chronic knee pain involves preventing flare-ups, reducing the irritation to the knee, and managing the pain effectively.

How to Prevent Chronic Knee Pain

As mentioned previously, knee pain is caused by a variety of factors. Some types of knee pain are challenging to prevent, but there are ways to minimise your chances of sustaining a knee injury.

• Stay slim or lose weight: The forces placed on your knee increase with weight gain. Keeping your weight in a healthy range will reduce the number of ligament and tendon injuries you experience.

• Stretch and strengthen your muscles regularly: Tight or imbalanced musculature often causes knee misalignment, resulting in pain. Regular stretching and strengthening ensure that your muscles provide the proper support for your knee.

• Exercise wisely: Chronic knee pain often responds poorly to exercises that involve pounding and twisting activities such as tennis, running, or squash. Consider exercises like swimming or cycling that take the weight off your knees. Always listen to your body, and if you are in pain, change what you are doing.

• Use the correct equipment when exercising: This may include using knee pads for protection when playing certain sports or replacing your running shoes to ensure they provide the proper support and cushioning. It may also involve using shoe inserts or orthotics to treat foot problems that may be contributing to the pain.

Anatomy

A weight-bearing joint, your knee is the largest joint in your body and one of the most complex. It is made up of the tibia (shinbone) and the lower end of the femur (thighbone) and covered in the front by the patella (kneecap). These bones are connected by ligaments (ACL, PCL, lateral and medial ligaments) and a tendon in the front known as the patella tendon. All the joints' surfaces are covered by cartilage, which helps the bones glide smoothly past one another.

Outlook

Chronic knee pain affects a large percentage of the population but varies from person to person. Many factors cause knee pain, including arthritis, ligament, tendon, cartilage injuries, bursitis, muscular tightness, gout, and bone tumours.

Chronic knee pain is diagnosed through a detailed examination or other investigative modalities. If conservative management fails, treatment may involve medications or injections to relieve pain, physiotherapy, and surgery.

The goal of treatment is to restore full pain-free mobility and prevent further injury.