Knee injections for pain and arthritis

Knee pain from osteoarthritis or an inflammatory flare-up can stall rehabilitation before it starts. A guided knee injection is one option for quietening things down enough to move properly again. Here's how the two injection options compare, what to expect, and what it costs.

When a knee injection is considered

Guided knee injections are most commonly used for:

Knee osteoarthritis — wear-related joint pain, often worse with load and at the end of the day
Inflammatory flare-ups — a knee that's become acutely swollen, hot, or unusually painful

Not every knee problem is helped by an injection. Ligament injuries, meniscus tears, and referred pain from the hip or back all need a different approach, which is exactly why every appointment starts with a full assessment rather than going straight to a needle.

In short: a knee injection is landmark-guided (delivered using anatomical landmarks, not a scanner) and settles pain and inflammation. It doesn't rebuild the strength around the joint that keeps knee pain from coming back, which is why it's paired with a rehabilitation plan rather than used alone.

Two options for the knee

Cortisone (steroid)

Reduces inflammation and pain relatively quickly. Usually the first choice for an acute flare-up or a knee that's become hot and swollen.

Sodium hyaluronate (Ostenil)

Supplements the knee's natural joint fluid rather than reducing inflammation directly. Often considered for osteoarthritis-related pain, particularly where repeated steroid use isn't desirable.

Which one fits depends on how irritable the joint is, how much wear is involved, and what you're hoping to achieve — decided together after assessment, not before it.

What happens at your appointment

Assessment. History and examination to confirm the knee (not the hip, back, or something else) is the source of the problem, and that an injection is appropriate.
Consent. Anatomical landmarks are identified by palpation; risks, alternatives, and which injection type fits best are explained properly.
The injection. Skin is cleaned and the injection delivered using precise anatomical landmarks. Most take under a minute.
Aftercare and the rehab plan. Clear aftercare guidance, a written report, and a programme to build the strength and control that protects the knee going forward — with full access to Suggs Gym's equipment for 1:1 guided rehab.

Risks and side effects

Both injection types are well-established and generally safe, but neither is risk-free. Common, temporary effects for cortisone injections include a post-injection pain flare for a day or two, facial flushing, and occasional skin changes at the injection site. People with diabetes may see a temporary rise in blood sugar. Infection is rare for either injection type. Repeated steroid injections into the same joint are used cautiously, one more reason an injection is paired with rehabilitation rather than repeated indefinitely.

What does it cost?

£195 Guided knee injection includes the assessment, the injection itself, and a written report. Self-funded; no GP referral required.

An injection buys you a window, rehab is what you do with it

The honest version: a knee injection is a bridge, not a fix. Its value is the window of reduced pain it opens for the quad, hip, and calf strengthening that actually protects the joint long-term. At this clinic the injection and the rehabilitation plan come from the same clinician, in a gym environment built for exactly that kind of progressive loading work, so nothing gets lost in a handover between different providers.

Frequently asked questions

Does a knee injection hurt?

Most people describe brief discomfort similar to any injection. A local anaesthetic is usually mixed in, so the knee often feels numb for a few hours afterwards. Some people notice a short flare of soreness in the first 24–48 hours before the steroid takes effect.

How long does a knee injection last?

A cortisone injection typically settles pain and inflammation for several weeks to a few months, which is usually enough time to make real progress with rehabilitation. Sodium hyaluronate (Ostenil) tends to take effect more gradually and is often used for longer-term osteoarthritis management.

Can I have a knee injection if I have arthritis?

Yes, knee osteoarthritis is one of the most common reasons for a guided knee injection. Which injection type suits you best depends on how irritable the joint is and what you're hoping to achieve, which is why every injection starts with a full assessment.

Do I need a GP referral for a knee injection?

No. You can self-refer directly. Every injection appointment starts with a full assessment, and an injection only goes ahead if it's clinically appropriate for your knee.

Is a knee injection better than physiotherapy alone?

They do different jobs, not competing ones. An injection can quieten pain and inflammation quickly; physiotherapy addresses the strength, movement, and load issues that got the knee into trouble in the first place. Most people do best with both, sequenced together rather than choosing one. (See our physiotherapy vs injection therapy guide for more on how that decision gets made.)

This guide is general information written by a physiotherapist, not a substitute for individual assessment. Knee pain has many causes. If yours isn't improving, get it assessed properly.