Knee injuries: a guide

The knees are the body’s largest joints that are put under a lot of stress daily, meaning that they are particularly susceptible to injury. In this article, a consultant orthopaedic surgeon shares the most common injuries to the knees, and how they can be treated.

The knee is located at the junction of the thigh bone (femur) and the tibia (shin bone), which are topped by the kneecap (patella) and surrounded an assortment of muscles, ligaments (like the anterior cruciate ligament, commonly referred to as the ACL), and cartilage (such as the meniscus).

The knees are a fundamental structure for human movement. They enable walking, sitting, crouching, dancing, jumping, cycling… knees are used constantly in daily life. They support a lot of the body’s weight, and help maintain balance. Intense activity and overuse can lead to the wearing down of cartilage and tendon damage, or sudden movements and impact can cause trauma.

The signs that something may be wrong with the knee are:

• Knee pain, typically quite suddenly
• Knee swelling
• Difficulty putting weight and pressure on the knee
• A loud popping or tearing sound
• Bruising
• Sensitivity

What are the kinds of knee injuries?

Knee injuries are not uncommon among professional athletes and sports hobbyists, but the average person who does only a moderate amount of physical activity could still suffer from a fall or a sprain. The ligaments and tendons are the most delicate part of the knees and are most likely to become damaged.

Some of the many kinds of knee injuries or pain that can occur due to excessive strain from sports include:

• Ligament tears, e.g. an ACL tear, which can occur when the knee twists or bends abnormally, such as sideways. Fracture,
• Runner’s knee, which is an inflammation of the patellar tendon, or Jumper’s knee, which is small tears in the patellar tendon. Both are common in athletes.
• Bursitis, which is inflammation of fluid-filled sacs near the joint that become inflamed due to constant strain and repetitive movement on the knees.
• Meniscus tears, where the meniscus cartilage that cushions the knees tears and causes the ends of the tibia and the femur to rub together. This can either suddenly occur or over time with wear and tear.
• Fractures, which are damage to the bone, most commonly the patella but the femur or the tibia can also be fractured.
• Dislocations, which are when the bones slip out of place or alignment. Both dislocations and fractures can happen due to a sudden impact, accident, or fall.

How are knee injuries treated?

Some injuries can be looked after at home, such as minor sprains. For more serious conditions or issues, there are surgical and non-surgical options that can be explored – however, this depends on the exact nature of the injury.

To treat knee injuries at home, one of the best things the patient can do is follow the RICE method:

• Rest
• Ice the area
• Compress to help with managing swelling and blood flow
• Elevate the knee above the level of the heart

Even if the injury is more serious, the above steps will be key in minimising pain and protecting the injury until medical intervention can be acquired.

To manage a knee injury non-surgically, methods include knee braces that can be used to support the knee and keep it in alignment whilst healing occurs or just to maintain the correct form, and physical therapy to strengthen the knee and the surrounding structures and restore stability and the range of mobility. Painkillers may be prescribed to manage pain while the patient rests and recovers.

Surgery is only recommended for extreme damage that requires urgent action, and when other methods have not been fruitful. Ligament and tendon tears will take longer to heal, and fractures and dislocations will need the bones to be reset properly so that there is no future deformity that restricts mobility.

An arthroscopy is one of the most common procedures for the knees, with a variety of applications, from a diagnostic tool to a reparative procedure. Using a few small incisions around the knee, a surgeon can access the internal structures with instruments and insert a tool that has a camera and light on the end called an arthroscope. With it, they can assess and address the damage to the knee. Arthroscopy can be used to address many of the knee injuries that occur in athletes and during sports, such as fractures, torn meniscus, or tendonitis. Grafts to replace ruined tissue can also be performed during arthroscopies, where donated tissue is used to repair damage – for example, an ACL repair.

For very severe damage to the knee, there is the option of a knee replacement, where bone components of the joint are replaced with artificial implants made of plastic, silicone, and metal. The worn or faulty tops of the leg bones tend to be what is replaced, where they are cut off and implanted with the prosthesis and the kneecap is put back in place.