A routine test procedure, knee X-ray, produces the images of the knee’s anatomy and is helpful in diagnosing the abnormalities of the knee joint. Doctors suggest getting an X-ray to help with the diagnosis of or to monitor a patient’s progress of a knee condition.
Did the doctor recommend a knee X-ray for you or someone you know? Here is everything you need to know about it.
Knee X-ray: Overview
Knee X-ray is an imaging test that gives a black-and-white image of the knee joint and the surrounding area. Parts of the thigh bone (femur), parts of the lower leg bones (tibia and fibula), the kneecap (patella), and some soft tissues are usually visible in this picture. A short burst of radiation is passed through the knee in an X-ray imaging procedure, which allows the lab technician to produce a clear knee joint X-ray. The bones absorb most of this radiation and appear white on the X-ray, whereas the soft tissue—fat and muscle—allows most of the radiation to pass through and appear in various shades of grey. The procedure is generally very quick and painless; however, the patient may experience some pain while setting up for the imaging.
The lab technician will take a picture of your knee in an anteroposterior view or AP (from the front), a lateral view (from the side), or a sunrise view of the kneecap (when the knee is bent).
When is a knee X-ray recommended?
A knee bone X-ray helps in the diagnosis of a health condition affecting the knee and for pre-operative planning. The doctor may order an X-ray, most likely after a physical examination, if the patient is experiencing any of the following symptoms:
- Pain
- Deformity
- Tenderness
- Stiffness
- Inability to walk or use the joint or extreme pain during movement
- Grinding in the knee
The doctor might also recommend a bilateral X-ray, that is, an X-ray of both joints, if they suspect a problem with both knees.
What is observed on the X-ray?
The doctor will look for the following on a knee X-ray:
- Changes in the soft tissue to check for swelling and excess fluid within the knee
- Quality of the bone to detect abnormalities such as bone disorders or thinning of the bone
*A bone density test is used to evaluate bone density.
- Alignment of the knee joint, which can be assessed if the X-ray image is taken while the patient was standing up
- Spaces in the joint between bones
- Early signs of arthritis, including bone spurs (a bony growth on the edge of a bone)
- Trauma or fracture of the joint or nearby bones
In addition, a knee X-ray can detect the following conditions as well:
- Joint dislocation
- Bone cysts or fluid-filled spaces
- Bone cancer
- Bone tumour
- Changes in the bone that occur in certain metabolic disorders such as osteoporosis
How much does a knee X-ray cost?
The cost of a knee X-ray depends on various factors such as the location, number of X-rays required, hospital, and lab. On average, the cost of one knee X-ray ranges from INR 250 to 800. Some government hospitals may provide X-rays for diagnostic purposes at little to no cost. Some insurance providers also cover this cost at their network hospitals.
Preparing for a knee X-ray
There is not much preparation required for a knee X-ray. Wearing comfortable clothes that do not have any metal elements is preferable. Metal objects interfere with a detailed image, so watches, belts, hair pins, and other metallic objects should be avoided. Women who are getting an X-ray are advised to wear a pull-on/sports bra without any metal as the technician will likely ask them to remove it for the X-ray.
For any doubts or questions, it is better to consult with the doctor or the lab technician in advance.
Knee X-ray procedure
After reaching the radiology centre, the patient will be guided the technician to the X-ray imaging room or section. They will ask the patient to remove any jewellery or other metal objects that might interfere with the imaging test. If the patient needs a change of clothes or their clothes are hindering the imaging process, the technician will provide them a hospital gown. The body parts that are not being imaged might be covered with a shield (lead apron) to prevent nonessential radiation exposure.
The technician will then position the patient according to the type of imaging required by the doctor. They will then operate the machine form behind a wall or in an adjoining room. To take a clear picture, the technician will recommend the patient to hold still when taking the picture; it usually takes 2 to 3 seconds. However, they may need to take another picture if the previous one wasn’t clear enough. The whole procedure usually takes about 5 to 10 minutes.
Who cannot get a knee X-ray
Pregnant women are usually not recommended an X-ray for diagnostic or other purposes. If they need an X-ray, adequate precautions are taken to prevent any damage to the foetus from the radiation. If someone is pregnant or planning to conceive, it is better to inform the lab technician in advance.
The doctor might also recommend a magnetic resonance imaging (MRI) scan for pregnant women as it does not use radiation.
What happens after the X-ray?
After the X-ray imaging is done, the results can shared within a few minutes. There is no special care that one needs to take after an X-ray except for the measures recommended by the doctor. Later, the doctor will examine the knee X-ray image and make a diagnosis or recommend more tests. Sometimes, the radiologist at the imaging centre will also analyse the X-ray images and attach a report with the results or send them directly to the concerned doctor.
The doctor will prescribe a suitable care plan after making the diagnosis and ask for follow-up X-rays after a certain period of time if the patient has a fracture or other conditions. These follow-up sessions help monitor the progress or any changes that occur over time.
