Knee Education

Knee Joint Health

Knee Education

The knee is the largest and strongest joint in the body that is made up of the lower end of the femur (thighbone), the upper end of the tibia (shinbone) and the patella (kneecap). The ends where the three bones connect are covered with articular cartilage, a smooth and slippery substance that protects and cushions the bones. The meniscus (two wedge-shaped cartilages) act as the ‘shock absorbers’ between the thighbone and shinbone; it is tough and rubbery, helping to cushion the joint and keep it stable. The knee joint is surrounded by a thin lining called the synovial membrane that releases a fluid, lubricating the cartilage and reducing friction.

Collateral ligaments on the sides of the knee control sideway motions and brace it against any unusual movements. The medial collateral ligament is on the inside, and lateral collateral ligament is on the outside. On the inside of the knee joint there are cruciate ligaments that cross each other to form an “X” with the anterior cruciate ligament in front and the posterior cruciate ligament in the back. The cruciate ligaments control the back and forth motions.

What you need to know:
Arthritis

Arthritis is inflammation of one or more of the joints, with the primary symptoms such as pain, swelling and stiffness. Any joint in the body may be affected by arthritis, but it is particularly common in the knee, making it hard to do many everyday activities like walking or climbing stairs. There are more than 100 different forms of arthritis, with the most common ones are osteoarthritis and rheumatoid arthritis. While it is mainly an adult disease, some forms affect children as well. Although there is no cure for arthritis, there are many treatment options that are available to help manage the pain and help people stay active.

Causes
Osteoarthritis commonly happens over time, as a degenerative ‘wear-and-tear’ disease that occurs to older patients. Rheumatoid arthritis on the other hand, is an autoimmune disease, which means that the immune system attacks its own tissues, damaging normal tissues, cartilage and ligaments, and softens the bones, causing lots of pain in the joints. Post-traumatic arthritis is another form of arthritis that develops after an injury to the knee.

Symptoms
A knee joint that is affected by arthritis may be painful and inflamed. Generally, the pain develops gradually over time, although sudden onset is also possible. Other symptoms include:

  • Stiff and swollen joints, making it difficult to bend or straighten the knee
  • Pain and swelling that becomes worse in the morning, or after sitting or resting
  • Pain that flares up after vigorous activities
  • Knees may ‘lock’ or ‘stick’ during movement; it may creak, click, snap or make a grinding noise (crepitus) due to loose fragments of cartilage and other tissues that interfere with the smooth motion of the joints
  • Pain that causes a feeling of weakness or ‘buckling’ in the knee
  • Increased joint pain during rainy or colder weather
  • Knee deformity that indicates severe forms of arthritis

Diagnosis
The doctor will first talk about your symptoms and medical history, and then conduct a physical examination and possibly order diagnostic tests such as X-rays or blood tests.

During physical examination, the doctor will look for the following problems:

  • Joint swelling, warmth, or any redness
  • Tenderness around the knee
  • Range of passive (assisted) and active (self-directed) motion
  • Any joint instability
  • Crepitus (a grating sensation inside the joint) with movement
  • Any knee pain when weight is placed
  • Any problems in the way you walk
  • Any other signs of injury to the muscles, tendons and ligaments surrounding the knee
  • Any involvement of other joint arthritis (indication of rheumatoid arthritis)

Imaging tests such as X-rays create detailed pictures of dense structures, like bones. They can help to distinguish among the various forms of arthritis. An arthritic knee may show a narrowing of joint space, changes in the bone and formation of bone spurs (osteophytes).

Other imagine tests such as MRI scans, CT scans or a bone scan may be ordered to determine the condition of bone and soft tissues of the knee. Blood tests may also be recommended to determine the type of arthritis.

Types of Arthritis?
The major types of arthritis that affect the knee are osteoarthritis, rheumatoid arthritis and post-traumatic arthritis.

  • Osteoarthritis
    Osteoarthritis is the most common form or arthritis in the knee, it is a degenerative ‘wear-and-tear’ type of arthritis that mostly occur in people 50 years old or older, but may also occur in younger patients. With osteoarthritis, the cartilage in the knee joint gradually wears away, it becomes rough and thus the protective space between the bones decreases, resulting in bone rubbing on bone, causing painful bone spurs.

    Osteoarthritis develops gradually over time, and the pain it causes worsens with age.
  • Rheumatoid arthritis
    Rheumatoid arthritis is a chronic disease that attacks multiple joints throughout the body, including the knee joint. It usually affects the same joint on both sides of the body. With rheumatoid arthritis, the synovial membrane that covers the knee joint begins to swell, resulting in knee pain and stiffness. Rheumatoid arthritis is an autoimmune disease, meaning that the immune system attacks its own tissues, damaging normal tissues, cartilage and ligaments, and softens the bones.

Post-traumatic arthritis
Post-traumatic arthritis develops after an injury to the knee; a broken bone may damage the joint surface, leading to arthritis years after the injury. Meniscal tears and ligament injuries can cause instability and additional wear on the knee joint, which then causes arthritis over time.

Treatments
There is no cure for arthritis, but a number of treatments are available to help relieve the pain and disabilities. As with other arthritic conditions, initial treatment of knee arthritis is non-surgical, and a range of treatment options such as physical therapy, assistive devices, medications and lifestyle modification help patients alleviate the amount of pain on the knee joints.

The doctor may recommend surgical treatments if the arthritis pain causes severe disability and is not able to be relieved by non-surgical methods.

Recovery
Post-surgery and rehabilitation plays a vital role in getting you back in shape for your daily activities. physical therapy and strengthening programme will be recommended to further protect your joints from future injuries.

Anterior Cruciate Ligament (ACL) Injuries

ACL injuries are common in athletes who participate in high-demand sports like soccer, football and basketball. It is a sprain or tear in the anterior cruciate ligament. About half of ACL injuries occur along with damage to other structures in the knee, such as articular cartilage, meniscus or other ligaments. An ACL injury may require surgical treatment to fully regain knee function, and it is dependent on the severity of the injury and the patient’s activity level.

Causes
The anterior cruciate ligament can be injured in several ways:

  • Rapid change in direction
  • Sudden stopping
  • Slowing down while running
  • Incorrect jump landing
  • Direct contact or collision, such as a football tackle

Several studies showed that female athletes have a higher incidence of ACL injuries than male athletes, proposedly due to differences in physical conditioning, muscular strength and neuromuscular control. Other suggested causes include differences in pelvis and lower extremity leg alignment, increased looseness of ligaments, and the effects of estrogen on ligament properties.

Symptoms
When the ACL is injured, there might be a ‘popping’ noise and the knee may feel like it is giving out from underneath. Other typical symptoms include:

  • Pain with swelling within 24 hours of injury. If this symptom is ignored, the swelling and pain may resolve on its own. However, if return to sports during this ‘self-recovery’ period, the knee will probably be unstable, causing risk of further damage to the cushioning cartilage (meniscus) of the knee
  • Loss of full range of motion
  • Tenderness along the joint line
  • Discomfort while walking

Diagnosis
During the first visit, the doctor will talk about any symptoms or medical history. A physical examination will be performed to check all the structures of the injured knee, and a comparison to the non-injured knee will be done. Most ligament injuries can be diagnosed via a thorough physical knee examination.

Imaging tests such as X-rays and MRI scans will be ordered as well. X-rays can show whether the injury is associated with a broken bone, while MRI scans – although usually not required to make a diagnosis – create better images of soft tissues.

Types of ACL Injuries?
ACL injuries are considered ‘sprains’, and are graded on a severity scale

  • Grade 1 Sprain
    Under this grade, the ligament is considered to be mildly damaged; it has been slightly stretched, but is still able to help keep the knee joint stable.
  • Grade 2 Sprain
    A Grade 2 Sprain stretches the ligament to the point where it becomes loose, often referred to as a partial tear of the ligament
  • Grade 3 Sprain
    This type of sprain is most commonly referred to as a complete tear of the ligament, and it has been split into two pieces, causing the knee joint to be unstable. Partial tears of the ACL are rare as most ACL injuries are complete or near complete tears.

Treatments
Treatments for ACL injuries and tears vary depending on the severity of the injury and upon patient’s individual needs. A young athlete involved in agility sports will most likely require surgery to safely return to the field. Less active, usually older patients may be able to return to a quieter lifestyle without invasive surgery.

A completely torn ACL injury will not heal without surgery. Non-surgical treatment may be effective for elderly patients or those with low activity level. If the overall stability of the knee is intact, the doctor may recommend simpler, non-surgical options such as bracing, assistive devices and physical therapy to strengthen leg muscles and support.

Surgical treatments such as ligament reconstruction and grafts may be considered to replace the torn ligament.

Recovery
Rehabilitation plays a vital role regardless of the involvement of non-surgical or surgical treatments to regain function of the knee joint. A customised physical therapy programme will help to regain knee strength and motion, focusing on returning motion to the joint and surrounding muscles, followed by a strengthening programme to protect new ligaments.

Meniscus Tears

Meniscus tears are among the most common knee injuries, especially athletes who play contact sports, have an increased risk for meniscus tears. It is most commonly referred to as a torn cartilage in the knee, and can happen to anyone at any age.

Causes
Sudden meniscus tears often happen during sports, players may squat incorrectly and twist the knee, causing it to tear. Direct contact like in a tackle, sometimes causes the tear. In older people, meniscus tears are mostly degenerative, the cartilage weakens and wears thin over time as aged and worn tissues are more prone to tears. Just an awkward twist when getting up from a chair may be enough to cause a tear, if the menisci have weakened with age.

Symptoms
When a meniscus is torn, there might be a ‘popping’ sensation, most people can still walk on that injured knees, and many athletes keep on playing with a tear. However, the knee will gradually become more stiff and swollen after 2 or 3 days. Without proper treatment, a piece of meniscus may become loose and drift into the joint, causing the knee to slip, pop or lock altogether.

Other common symptoms of meniscus tears are:

  • Pain, with stiffness and swelling
  • Catching or ‘locking’ of the knee
  • The sensation of the knees ‘giving away’
  • Not able to move the knee through its full range of motion

Diagnosis
A physical examination will be performed after a check on symptoms and medical history. The doctor will check for tenderness along the joint line where the meniscus sits, which often signals that a tear is present. One of the main tests for meniscus tears is the McMurray test – the doctor will bend the knee, then straighten it, and rotate it. These motions put tension on a torn meniscus, and if a tear is present, a clicking sound will be heard.

Imagine tests such as X-rays and MRI scans may also be performed to confirm the diagnosis.

Types of Meniscus Tears?
Menisci can tear in various ways, and are noted by how they ‘look’, as well as where the tear occurs in the meniscus. Common tears include bucket handle tear, flap tear, radial tear, and degenerative tear.


(Left) Bucket handle tear. (Right) Flap tear.


(Left) Radial tear. (Right) Degenerative tear.

Treatments
The type of treatment proposed depends on the type of tear that is diagnosed, its size and the location of tear. A meniscus tear on the outside may usually heal on its own. A tear on the inside however, may require surgical methods.

Any treatment that the doctor recommends will also factor in the patient’s age, activity level, and any other related injuries. If symptoms persist even after non-surgical treatments such as the RICE method (Rest – Ice – Compression – Elevation) and non-steroidal anti-inflammatory medications are recommended, a knee arthroscopy may be suggested.

Recovery
Rehabilitation exercises that can be carried out at home will be recommended after non-surgical and surgical treatments of to heal the menisci. Recovery usually takes approximately 3 weeks to 3 months, depending on the treatment performed. With proper treatment and post-treatment care, patients often return to their pre-injury abilities.