Knee injections for pain and mobility

Patients experiencing knee issues, such as a loss of mobility and pain, may benefit from treatment that involves injections directly into the knee joint. In this article, a consultant orthopaedic surgeon explains the types of knee injections, and why surgery isn't always the answer.

Common knee issues

The knees are a pair of joints that experience high activity, as we use them to sit, walk, crouch, lift, and many other movements. Because of this, they can be quite susceptible to injury and problems that develop gradually. The knee is comprised of the leg bones (the tibia, fibula, and femur), the kneecap (the patella), and a variety of ligaments, muscles, and tendons.

When the knees stop functioning as they should, they can become swollen, stiff, and movement comes with significant pain and effort. This could be due to:

• Osteoarthritis, a degenerative condition where the cartilage wears away over time, leading to pain, stiffness, and swelling. Inflammatory conditions such as rheumatoid arthritis also cause joint damage through an autoimmune process.
• Trauma, including Injuries such as fractures, ligament tears, or dislocations.
• Overuse and wear-and-tear, such as repetitive strain. This can occur due to involvement in sports and exercise, or as a byproduct of tasks like picking up boxes often or working from the floor. This is more common in athletes and physical labourers.

What are knee injections?

Knee injections are an avenue of treatment for knee issues. When knees first become dysfunctional or painful, it is important to address them sooner rather than later, as the condition is likely to worsen, necessitating more invasive treatment like joint replacement.

As to what the injection actually is, there are several options, and which is used depends on the needs of the patient. There are three main types of injected substances utilised in knee treatments:

• Steroids, used to reduce pain and inflammation. A downside to steroid joint injections is that they can further damage cartilage and tendons with prolonged usage.
• Platelet-rich plasma (PRP) injections, which reduce inflammation and encourage healing with platelets that are acquired from the patient’s own blood (autologous). This works by facilitating cell renewal and can contribute to cartilage, tendon, and ligament repair.
• Hyaluronic acid, which is a naturally occurring lubricant found in the body. It is mainly used to treat pain from osteoarthritis.

The type of knee injection that a patient should receive is dependent on their condition, medical history, and expectations. After the injection has been administered, patients should rest for a day or so to allow the substance to settle. It is not recommended to return to strenuous activities and sports immediately; rather, patients should aim for gentle movements and gradually increase according to their comfort and the knee’s ability.

What happens during and after a knee injection

The process is fairly simple: the injection is administered directly into the knee joint within a clinical setting; most doctors do not even need to utilise imaging scan guidance, though it may be necessary for some cases where the anatomy or injury is complex. This is an outpatient procedure and will take less than 30 minutes.

Knee injections are a non-invasive procedure and are recommended for patients who are not candidates or do not want to undergo knee surgery. When pain and inflammation improve, mobility should consequently improve as well.

Most patients will return within six months, the typical lifespan for the results, for another dose and assessment of their knee. Their treatment plan may change if they have had a negative reaction to the injection, or if their condition has changed for the better or worse.

Are knee injections an alternative to knee surgery?

Knee injections are not a replacement for knee surgery, but they are most effective for mild to moderate knee issues, and can be utilised to delay the need for such surgery.