Joint injections for osteoarthritis: what are the different types?

Osteoarthritis is the most common type of arthritis and causes joint pain and stiffness. It occurs with age as the cartilage that covers the ends of the bones inside your joints wears away. It, therefore, usually affects those aged over 50 but can develop earlier, especially if your genetics or lifestyle increases your risk eg if you regularly take part in high-impact sports or have a manual job that strains your joints. 

Joint injections are one of several different treatments to help relieve the symptoms of osteoarthritis and can be applied to any affected joints.

When are joint injections suitable?

Joint injections may be recommended in your treatment journey when your symptoms are significant and painkillers and anti-inflammatory medication are not effective but the arthritic changes are mild to moderate and don’t require major surgery (eg joint replacement).

They can also be used if your osteoarthritis is advanced but joint replacement surgery is not an option, either because you would prefer not to undergo surgery or because your body is not fit enough to go through surgery.

How are joint injections given?

Joint injections are administered using a syringe with a needle. You may first have a local anaesthetic injection or this may be given in combination with your joint injection.

Depending on the size and nature of your joint, imaging technology, such as ultrasound scanning or X-ray fluoroscopy, may also be needed to guide your injection.

Types of joint injections

There are four main types of joint injections for osteoarthritis: steroids, lubricants, blood proteins and hydrogels.

Blood protein and hydrogel injections are newer innovations that aim to provide longer-lasting results, in the order of years, than traditional steroid and lubricant injections, which may only last for several months.

Blood protein and hydrogel injections take longer to have an effect, usually around six weeks. While the effects of steroid and lubricant injections are faster, they can increase your joint pain for a few days afterwards and temporarily suppress your immune system, leading to a theoretical risk of COVID-19 infection for a few days afterwards.

Steroid injections

This is the most common type of joint injection for osteoarthritis. There are different types of steroids with effects that vary in duration and that have different side effects.

The effectiveness of steroid injections varies considerably from one individual to the next. This is not dependent on the severity of your osteoarthritis but how your body in particular responds.

Lubricant injections

These injections are made of synthetic or natural forms of hyaluronic acid. Synthetic forms are more commonly used today as natural forms are sourced from animal cartilage and connective tissue. Synthetic hyaluronic acid also lasts longer than natural forms, so you won’t need to have as many injections.

More recently, injections containing both hyaluronic acid and collagen have shown good results with patients finding relief from their symptoms for up to 12 months.

Blood protein injections

At a cellular level, osteoarthritis causes inflammation in the joints, which causes joint pain and swelling. The inflammatory fluid produced in an arthritic joint contains inflammatory proteins called cytokines and interleukins. The body also produces other interleukins and cytokines that have anti-inflammatory properties.

These anti-inflammatory blood proteins can be collected from your blood, concentrated and injected into your affected joints. This increases the effectiveness of your body’s own anti-inflammatory response, protecting your cartilage and reducing inflammation. This consequently reduces your pain and swelling and slows down the progress of your osteoarthritis.

Hydrogel injections

This involves injecting your affected joints with a synthetic polyacrylamide gel. This gel binds to the soft tissue covering around your joints (synovium) and prevents pro-inflammatory proteins from passing through into your joint, which consequently reduces pain and swelling and improves joint function.