A knee X-ray gives a quick picture of the bones of the joint. Here is what it can and cannot show, when it is usually not the first step, and how referral works for a private X-ray.
Search X-ray providers near youKnee pain is common, and an X-ray is one of the oldest and simplest ways to look at the joint. It takes only a few minutes and shows the bones of the thigh, shin and kneecap where they meet. It is often used when a doctor wants to check for a broken bone after an injury, or to look at the joint when arthritis is suspected.
FindScan is a directory and enquiry service, not a healthcare provider. We do not scan anyone or give medical advice. You can compare private clinics that offer knee X-rays, see each clinic's own listed price, and send an enquiry to the clinic you choose.
The NHS describes X-rays as a way to check your bones for a fracture after an accident, and to find out whether symptoms could be caused by a particular condition. For the knee, that usually means looking at the shape and alignment of the bones, the space between them, and any obvious break.
An X-ray is good at showing bone. It is not the usual test for the soft structures inside the knee, such as ligaments, cartilage and the menisci. If your doctor or physiotherapist suspects a soft tissue injury, they may suggest an MRI instead. Our knee MRI scan page and our guide to what a knee MRI shows explain the difference in more detail.
A clinician may request a knee X-ray for reasons such as:
The NHS says osteoarthritis most often causes problems in the knees, hips and small joints of the hands. It also says a GP can usually diagnose osteoarthritis by asking about your symptoms and examining your joints, and that further tests such as X-rays or blood tests are not usually necessary, but may be used to rule out other possible causes, such as rheumatoid arthritis or a fractured bone.
Many knee problems are assessed first by a GP or physiotherapist, without imaging. The NHS knee pain page suggests resting the knee, using an ice pack wrapped in a tea towel for up to 20 minutes every 2 to 3 hours, and taking painkillers such as paracetamol or ibuprofen. It advises seeing a GP if knee pain does not improve within a few weeks.
Most sprains and strains can be treated at home without seeing a GP, according to the NHS. If you are unsure whether you need imaging at all, our guide on seeing a GP before a scan may help.
A private X-ray is not the right route for a serious or obvious injury. The NHS knee pain page advises contacting NHS 111 if:
The NHS sprains and strains page says to go to A&E or call 999 if you heard a crack when you were injured, if the injured part has changed shape or is pointing at an odd angle, if it is numb, tingling or has pins and needles, or if the skin looks blue or grey or feels cold. It also notes that an X-ray can sometimes be done at an urgent treatment centre. If you think you have broken a bone, use urgent NHS care rather than waiting for a private appointment.
X-rays use ionising radiation, so they are covered by the Ionising Radiation (Medical Exposure) Regulations 2017, known as IR(ME)R. Under these regulations every exposure must be requested by a referrer, who supplies the relevant medical information, and must be justified and authorised by a practitioner as showing a sufficient net benefit. That justification must weigh up the benefits against the risks and consider alternative techniques that involve less or no ionising radiation.
In practice, this means you cannot simply ask for an X-ray without a clinical reason. A referral may come from your GP, a physiotherapist, a consultant or another suitable clinician. Some private clinics arrange the referral through their own doctor or a clinical review of your symptoms. Each clinic sets out how it handles this, so check when you enquire. Our guide to getting an X-ray without a GP referral explains the options.
The NHS advises not wearing anything that has metal in it, such as jewellery or clothes with zips or poppers, and you may be asked to change into a gown. For a knee X-ray it can help to wear shorts or loose trousers. Tell the clinic beforehand if you are pregnant or might be pregnant. IR(ME)R also requires staff to ask anyone of childbearing potential whether they are pregnant or breastfeeding, where relevant.
During the X-ray the radiographer positions your leg, and you stay still while each image is taken. The NHS says an X-ray should only take a few minutes and that you will not feel anything when the image is taken. Images may be taken from more than one angle. You can usually leave as soon as the X-ray is done. See our guide on how to prepare for your scan for general tips.
The NHS says X-rays are usually very safe and serious complications are rare, though if you have lots of X-rays there is a very small risk that the radiation could cause cancer. The UK Health Security Agency (UKHSA) publishes typical doses for common examinations. For limbs and joints other than the hip, it lists a typical effective dose of less than 0.01 mSv, equivalent to less than 1.5 days of natural background radiation, with a lifetime additional risk of fatal cancer of 1 in a few million. Read more in our X-ray radiation safety guide.
Your images are reported by an appropriately qualified clinician. The NHS says you should be told when you will get your results. Report times differ between providers, so the clinic will tell you how long its report takes. The report usually goes to whoever referred you, who can explain what it means and discuss next steps. Our guide on how long scan results take has more on this.
Prices vary from clinic to clinic. They can depend on the number of views needed, whether one or both knees are imaged, whether a clinical review or referral is included, and the region. FindScan shows each clinic's own listed price, as set by the clinic, without mark-up. Our guide to private X-ray costs in the UK covers what to ask about.
Search for X-ray clinics near you, compare locations and listed prices, and check how each clinic handles the referral and justification step. When you have found a clinic, send an enquiry through FindScan and we will pass your details to that clinic, which will contact you directly to arrange the next steps. See clinics near you or read more about private X-rays.
An X-ray mainly shows bone. Ligaments, cartilage and the menisci are soft tissues and are not usually assessed by X-ray. If a soft tissue injury is suspected, a clinician may suggest an MRI. See our knee MRI scan page.
Not usually. The NHS says a GP can often diagnose osteoarthritis from your symptoms and an examination, and that X-rays are not usually necessary, but may be used to rule out other possible causes such as rheumatoid arthritis or a fractured bone.
Every X-ray must be requested by a referrer and justified under IR(ME)R 2017. Some private clinics can arrange this through their own doctor or a clinical review, while others ask for a referral from your GP, physiotherapist or consultant. Check each clinic's approach when you enquire.
No. If you heard a crack, cannot put weight on your leg, or the knee has changed shape, the NHS advises getting urgent help. Contact NHS 111, go to an urgent treatment centre, or go to A&E. Call 999 in an emergency.
The NHS says an X-ray should only take a few minutes. Your total visit will be longer once you include checking in and changing, and the clinic can tell you what to expect.
UKHSA lists a typical effective dose of less than 0.01 mSv for X-rays of limbs and joints other than the hip, equivalent to less than 1.5 days of natural background radiation.
FindScan is a directory and enquiry service, not a healthcare provider, and nothing here is medical advice. Speak to a GP or another clinician about your symptoms.