Knee arthroscopy is surgery that is done to check for problems, using a tiny camera to see inside your knee. Other medical instruments may also be inserted to repair your knee.
Arthroscopy is surgery that is done using a tiny camera on the end of a tube to check for and treat joint problems.
Rotator cuff repair
This procedure is typically done on the knee, hip, ankle, shoulder, elbow, or wrist.
Three different types of anesthesia (pain management) may be used for arthroscopy surgery:
General anesthesia. You will be unconscious and unable to feel pain.
Painkilling medicine. Your joint may be numbed, and you may be given medicines that relax you. You will stay awake.
Spinal anesthesia. This is also called regional anesthesia. The painkilling medicine is injected into a space in your spine. You will be awake but will not be able to feel anything below your waist.
The area is cleaned and a pressure band (tourniquet) may be applied to restrict blood flow. The health care provider will then make a surgical cut into the joint. Sterile fluid is passed through the joint space to expand the joint and provide a better view.
Next, a tool called an arthroscope is inserted into the area. An arthroscope consists of a tiny tube, a lens, and a light source. It allows the surgeon to look for joint damage or disease.
Images of the inside of the joint are displayed on a monitor. One or two other surgical cuts may be needed so the doctor can use other instruments to remove bits of cartilage or bone, take a tissue biopsy, or perform other minor surgery. In addition, ligament repairs can be done using the arthroscope.
Why the Procedure is Performed
A number of different injuries and diseases may cause joint pain or problems.
Arthroscopy may be needed to:
Diagnose the cause of joint pain after an injury
Perform carpal tunnel surgery
Remove loose bone or cartilage fragments in the joint
Remove the lining of the joint. This lining is called the synovium, and it may become swollen or inflamed from arthritis.
Repair a torn ligament or tendon
Repair damaged cartilage or meniscus (the piece of cartilage that cushions the knee joint area)
The risks from surgery are:
Allergic reactions to medications
Other risks from this surgery include:
Bleeding into the joint
Damage to the cartilage, meniscus, or ligaments in the knee
Infection in the joint
Injury to a blood vessel or nerve
After the procedure, the joint will probably be stiff and sore for a few days. Ice is commonly recommended after arthroscopy to help relieve swelling and pain.
You can resume gentle activities, such as walking, immediately. However, using the joint too much may cause swelling and pain, and may increase the chance of injury. Do not restart normal activity for several days or longer.
You may need to make arrangements for work and other responsibilities. Your doctor may also recommend physical therapy.
Depending on your diagnosis, you may have other resrictions or need to do certain exercises.
Before the Procedure
You will usually have an MRI scan of the joint done before surgery is planned.
Always tell yoru doctor or nurse what drugs you are taking, even drugs, supplements, or herbs you bought without a prescription.
You will be asked to stop taking drugs that make it harder for your blood to clot beginning 2 – 3 weeks before surgery. These drugs include aspirin, ibuprofen (Advil, Motrin), and naproxen (Naprosyn, Aleve).
Ask your doctor which drugs you should still take on the day of your surgery.
You will usually be asked not to eat or drink anything for 6 – 12 hours before the procedure. Always let your doctor know about any cold, flu, fever, herpes breakout, or other illness you may have before your surgery.
You must sign a consent form. Make arrangements for transportation from the hospital after the procedure.
Arthroscopy – hip; Arthroscopy – wrist; Arthroscopy – ankle
Hypermobile joints are joints that move beyond their normal range of motion with little effort from the individual.
Hypermobile joints are joints that move beyond the normal range with little effort. Joints most commonly affected are the elbows, wrists, fingers, and knees.
Children are often more flexible than adults, but those with hypermobile joints can flex and extend their joints beyond what is considered normal. The movement is done without too much force and without discomfort.
Thick bands of tissue called ligaments help hold joints together and keep them from moving too much or too far. In children with hypermobility syndrome, those ligaments are loose or weak. This may lead to:
Arthritis, which may develop over time
Dislocated joints, which is a separation of two bones where they meet at a joint
Sprains and strains
Children with hypermobile joints also often have flat feet.
Hypermobile joints often occur in otherwise healthy and normal children. This is called benign hypermobility syndrome.
Rare medical conditions associated with hypermobile joints include:
There is no specific care for this condition. Persons with hypermobile joints have an increased risk for joint dislocation and other problems.
Extra care may be needed to protect the joints. Ask your health care provider for recommendations.
When to Contact a Medical Professional
Call your health care provider if:
A joint suddenly appears misshapen
An arm or leg suddenly does not move properly
Pain occurs when moving a joint
The ability to move a joint suddenly changes or decreases
What to Expect at Your Office Visit
Hypermobile joints often accompany other symptoms that, taken together, define a specific syndrome or condition. A diagnosis is based on a family history, medical history, and a complete physical exam.
Medical history questions that help document hypermobile joints in detail may include:
When did you first notice the problem?
Is it getting worse or more noticeable?
Are there any other symptoms, such as swelling or redness around the joint?
Is there any history of joint dislocation, difficulty walking, or difficulty using the arms?
The physical exam will include detailed examination of the muscles and skeleton. The joints may be moved to determine the direction and extent of mobility.
Further tests will depend on what condition is suspected.
Joint hypermobility; Loose joints; Hypermobility syndrome
Joint pain can affect one or more joints.
Arthritis (inflammation of joints)
Joint pain can be caused by many types of injuries or conditions. No matter what causes it, joint pain can be very bothersome.
Rheumatoid arthritis is an autoimmune disorder that causes stiffness and pain in the joints. Osteoarthritis involves growth of bone spurs and degeneration of cartilage at a joint. It is very common in adults older than 45 and can cause joint pain.
Joint pain may also be caused by bursitis (inflammation of the bursae). The bursae are fluid-filled sacs that cushion and pad bony prominences, allowing muscles and tendons to move freely over the bone.
Autoimmune diseases such as rheumatoid arthritis and lupus
Gout (especially found in the big toe)
Infectious diseases, including
Epstein-Barr viral syndrome
Rubella (German measles)
Injury, including fracture
Unusual exertion or overuse, including strains or sprains
Follow prescribed therapy in treating the underlying cause.
For nonarthritis joint pain, both rest and exercise are important. Warm baths, massage, and stretching exercises should be used as frequently as possible.
Anti-inflammatory medications may help relieve pain and swelling. Consult your health care provider before giving aspirin or NSAIDs such as ibuprofen to children.
When to Contact a Medical Professional
Contact your health care provider if:
You have fever that is not associated with flu symptoms
You have lost 10 pounds or more without trying (unintended weight loss)
Your joint pain lasts for more than 3 days
You have severe, unexplained joint pain, particularly if you have other unexplained symptoms
What to Expect at Your Office Visit
Your health care provider will perform a physical exam and ask you about your medical history. The following questions may help identify the cause of your joint pain:
Which joint hurts? Is the pain on one side or both sides?
How long have you been having this pain? Have you had it before?
Did this pain begin suddenly and severely, or slowly and mildly?
Is the pain constant or does it come and go? Has the pain become more severe?
What started your pain?
Have you injured your joint?
Have you had an illness or fever?
Does resting the joint reduce the pain or make it worse?
Does moving the joint reduce the pain or make it worse?
Are certain positions comfortable? Does keeping the joint elevated help?
Do medications, massage, or applying heat reduce the pain?
What other symptoms do you have?
Is there any numbness?
Can you bend and straighten the joint? Does the joint feel stiff?
Are your joints stiff in the morning? If so, how long does the stiffness last?
What makes the stiffness better?
Tests that may be done include:
CBC or blood differential
Sedimentation rate, a measure of inflammation
Blood tests specific to various autoimmune disorders
Physical therapy for muscle and joint rehabilitation may be recommended. A procedure called arthrocentesis may be needed to remove fluid from the sore joint.
This test is an x-ray of a knee, shoulder, hip, wrist, ankle, or other joint.
How the Test is Performed
The test is done in a hospital radiology department or in the health care provider’s office. The x-ray technologist will help you position the joint to be x-rayed on the table. Once in place, pictures are taken. The joint may be repositioned for different views.
How to Prepare for the Test
Inform the health care provider if you are pregnant. Remove all jewelry.
How the Test Will Feel
The x-ray is not uncomfortable, except possibly from positioning the area being x-rayed.
Why the Test is Performed
The x-ray is used to detect fractures, tumors, or degenerative conditions of the joint.
What Abnormal Results Mean
The x-ray may reveal arthritis, fractures, bone tumors, degenerative bone conditions, and osteomyelitis (inflammation of the bone caused by an infection).
The test may also be performed to investigate the following conditions:
Acute gouty arthritis (gout)
Adult still’s disease
Chronic gouty arthritis
Congenital dislocation of the hip
Non-gonococcal (septic) bacterial arthritis
There is low radiation exposure. X-rays are monitored and regulated to provide the smallest amount of radiation exposure needed to produce the image. Most experts feel that the risk is low compared with the benefits. Pregnant women and children are more sensitive to the risks of the x-ray.
X-ray – joint; Arthrography; Arthrogram
Changes in posture and gait (walking pattern) are as universally associated with aging as changes in the skin and hair.
The skeleton provides support and structure to the body. Joints are the areas where bones come together. They allow the skeleton to be flexible for movement. In a joint, bones do not directly contact each other. Instead, they are cushioned by cartilage in the joint, synovial membranes around the joint, and fluid.
Muscles provide the force and strength to move the body. Coordination is directed by the brain but is affected by changes in the muscles and joints. Changes in the muscles, joints, and bones affect the posture and gait, and lead to weakness and slowed movement.
Bone mass or density is lost as people age, especially in women after menopause. The bones lose calcium and other minerals.
The spine is made up of bones called vertebrae. Between each bone is a gel-like cushion (intervertebral disk). The trunk becomes shorter as the disks gradually lose fluid and become thinner.
In addition, vertebrae lose some of their mineral content, making each bone thinner. The spinal column becomes curved and compressed (packed together). Bone spurs, caused by aging and overall use of the spine, may also form on the vertebrae.
The foot arches become less pronounced, contributing to a slight loss of height.
The long bones of the arms and legs, although more brittle because of mineral loss, do not change length. This makes the arms and legs look longer when compared with the shortened trunk.
The joints become stiffer and less flexible. Fluid in the joints may decrease, and the cartilage may begin to rub together and erode. Minerals may deposit in and around some joints (calcification). This is common in the shoulder.
Hip and knee joints may begin to lose joint cartilage (degenerative changes). The finger joints lose cartilage and the bones thicken slightly. Finger joint changes are more common in women and may be hereditary.
Some joints, such as the ankle, typically change very little with aging.
Lean body mass decreases, caused in part by loss of muscle tissue (atrophy). The rate and extent of muscle changes seem to be genetically determined. Muscle changes often begin in the 20s in men and the 40s in women.
Lipofuscin (an age-related pigment) and fat are deposited in muscle tissue. The muscle fibers shrink. Muscle tissue is replaced more slowly, and lost muscle tissue may be replaced with a tough fibrous tissue. This is most noticeable in the hands, which may appear thin and bony.
Changes in the muscle tissue, combined with normal aging changes in the nervous system, cause muscles to have less tone and ability to contract. Muscles may become rigid with age and may lose tone, even with regular exercise.
EFFECT OF CHANGES
Bones become more brittle and may break more easily. Overall height decreases, mainly because of shortening of the trunk and spine.
Inflammation, pain, stiffness, and deformity may result from breakdown of the joint structures. Almost all elderly people are affected by joint changes, ranging from minor stiffness to severe arthritis.
The posture may become more stooped (bent) and the knees and hips more flexed. The neck may become tilted, and the shoulders may narrow while the pelvis becomes wider.
Movement slows and may become limited. The walking pattern (gait) becomes slower and shorter. Walking may become unsteady, and there is less arm swinging. Older people become tired more easily, and have less energy.
Strength and endurance change. Loss of muscle mass reduces strength. However, endurance may be enhanced somewhat by changes in the muscle fibers. Aging athletes with healthy hearts and lungs may find that performance improves in events that require endurance, and decreases in events that require short bursts of high-speed performance.
Osteoporosis is a common problem, especially for older women. Bones break more easily, and compression fractures of the vertebrae can cause pain and reduce mobility.
Muscle weakness contributes to fatigue, weakness, and reduced activity tolerance. Joint problems are extremely common. This may be anything from mild stiffness to debilitating arthritis (see osteoarthritis).
The risk of injury increases because gait changes, instability, and loss of balance may lead to falls.
Some elderly people have reduced reflexes. This is most often caused by changes in the muscles and tendons, rather than changes in the nerves. Decreased knee jerk or ankle jerk can occur. Some changes, such as a positive Babinski’s reflex, are not a normal part of aging.
Involuntary movements (muscle tremors and fine movements called fasciculations) are more common in the elderly. Inactive or immobile elderly people may experience weakness or abnormal sensations (paresthesias).
Muscle contractures may occur in people who are unable to move on their own or have their muscles stretched through exercise.
Exercise is one of the best ways to slow or prevent problems with the muscles, joints, and bones. A moderate exercise program can help you maintain strength and flexibility. Exercise helps the bones stay strong.
Consult with your health care provider before beginning a new exercise program.
A well-balanced diet with adequate amounts of calcium is important. Women need to be especially careful to get enough calcium and vitamin D as they age. Postmenopausal women, and men over age 65, need 1,200 – 1,500 mg of calcium and 400 – 800 international units of vitamin D per day. If you have osteoporosis, talk to your doctor about prescription treatments.
When a joint does not move fully and easily in its normal manner it is considered to have a limited range of motion. Motion may be limited by a mechanical problem within the joint, swelling of tissue around the joint, spasticity of the muscles, pain or disease.
Limited range of motion is a reduction in the normal distance and direction through which a joint can move.
Range of motion is the distance and direction of movement of a joint. Limited range of motion is a term meaning that a specific joint or body part cannot move through its normal range of motion.
Motion may be limited by a mechanical problem within the joint, by swelling of tissue around the joint, by stiffness of the muscles, or by pain.
Diseases that prevent a joint from fully extending may, over time, produce contracture deformities, causing permanent inability to extend the joint beyond a certain fixed position.
- Ankylosing spondylitis
- Cerebral palsy
- Congenital torticollis
- Dislocation (of most joints)
- Fracture of elbow
- Fractures through most joints
- Juvenile rheumatoid arthritis
- Legg-Calve-Perthes disease
- Nursemaid’s elbow, an injury to the elbow joint — extremely common
- Rheumatoid arthritis
- Septic joint (especially septic hip)
Your health care provider may recommend range of motion exercises, designed to increase muscle strength and flexibility. Continue these exercises at home.
When to Contact a Medical Professional
Visit your health care provider if a joint does not move fully and easily in its normal way. If a joint develops (new) changes in its ability to move, the affected part should be examined to determine the cause.
What to Expect at Your Office Visit
The health care provider will perform a physical examination and will ask you about your medical history. Questions may include:
- When did your symptoms start?
- How bad is it?
- What body part is affected?
- Does the limited range of motion affect more than one body area?
- Do you also have pain?
- What other symptoms do you have?
Note: Limited range of motion may be discovered by the health care provider during an examination for other conditions, and the affected person may or may not have been aware of its presence.
The muscular system, nervous system, and skeleton may be examined in detail. Depending on the cause, joint x-rays and spine x-rays may be needed. Other tests may also be done.
Physical therapy may be recommended.
Joints, particularly hinge joints like the elbow and the knee, are complex structures made up of bone, muscles, synovium, cartilage, and ligaments that are designed to bear weight and move the body through space. The knee consists of the femur (thigh bone) above, and the tibia (shin bone) and fibula below. The kneecap (patella) glides through a shallow groove on the front part of the lower thigh bone. Ligaments and tendons connect the three bones of the knee, which are contained in the joint capsule (synovium) and are cushioned by cartilage.
Joint swelling is the buildup of fluid in the soft tissue surrounding the joint.
Joint swelling may occur along with joint pain. The swelling may cause the joint to appear larger or abnormally shaped.
Joint swelling can cause pain or stiffness. After an injury, swelling of the joint may mean you have a broken bone or a tear in the muscle tendon or ligament.
Many different types of arthritis may cause swelling, redness, or warmth around the joint.
An infection in the joint can cause swelling, pain, and fever.
Joint swelling may be caused many different things, including:
- Ankylosing spondylitis
- Psoriatic arthritis
- Reactive arthritis
- Rheumatoid arthritis
- Septic arthritis
- Systemic lupus erythematosus
If the joint swelling occurs after an injury, apply ice packs to reduce pain and swelling. Raise the swollen joint so that it is higher than your heart, if possible. For example, if your ankle is swollen, lay down with pillows comfortably placed underneath your foot so that your ankle and leg is slightly raised.
For those with arthritis, your doctor’s treatment plan should be followed carefully.
When to Contact a Medical Professional
Call your health care provider immediately if you have joint pain and swelling with a fever.
Also call your health provider if you have:
- Unexplained joint swelling
- Joint swelling after an injury
A joint is where two or more bones come together, like the knee, hip, elbow or shoulder. Joints can be damaged by many types of injuries or diseases. Arthritis or simply years of use may cause a joint to wear away. This can cause pain, stiffness and swelling. Over time, a swollen joint can become severely damaged.
Treatment of joint problems depends on the cause. If you have a sports injury, treatment often begins with the RICE (Rest, Ice, Compression and Elevation) method to relieve pain, reduce swelling and speed healing. Other possible treatments include pain relievers, keeping the injured area from moving, rehabilitation, and sometimes surgery. For arthritis, injuries, or other diseases, you may need joint replacement surgery to remove the damaged joint and put in a new one.
NIH: National Institute of Arthritis and Musculoskeletal and Skin Diseases
What are the limitations of arthrography?
The limitations of arthrography include:
- Partial tears of the rotator cuff may not be detected with conventional arthrography.
- Some joint injuries cannot be detected with conventional (x-ray) arthrography including tears of the cartilage which can be found inside and along the edges of some joints, bruising of neighboring bones and injuries to ligaments outside the joint.
- MR arthrography images the interior of the joint well, but is not as effective as standard MRI in detecting abnormalities of bone and surrounding tissues.
What are the benefits vs. risks?
- Arthrography is particularly effective for detecting tears or lesions of the structures and ligaments of the joints, especially the knee, wrist and elbow, as well as rotator cuff tears or damage from a shoulder dislocation.
Exams involving x-ray imaging:
- No radiation remains in a patient’s body after an x-ray examination.
- X-rays usually have no side effects in the diagnostic range.
Exams involving MR imaging:
- MRI is a noninvasive imaging technique that does not involve exposure to ionizing radiation.
- MRI enables the discovery of abnormalities that might be obscured by bone with other imaging methods.
- The contrast material used in MRI exams is less likely to produce an allergic reaction than the iodine-based contrast materials used for conventional x-rays and CT scanning.
- Any procedure where the skin is penetrated carries a risk of infection. The chance of infection requiring antibiotic treatment appears to be less than one in 1,000.
Exams involving x-ray imaging:
- There is always a slight chance of cancer from excessive exposure to radiation. However, the benefit of an accurate diagnosis far outweighs the risk.
- Patients who have known allergies to iodine may have an adverse reaction to the contrast material. Because the contrast material is put in a joint and not a vein, allergic reactions are very rare, although in some cases, mild nausea to severe cardiovascular complications may result.
- Women should always inform their physician or x-ray technologist if there is any possibility that they are pregnant. See the Safety page for more information about pregnancy and x-rays.
- The effective radiation dose for this procedure varies. See the Safety page for more information about radiation dose.
Exams involving MR imaging:
- The MRI examination poses almost no risk to the average patient when appropriate safety guidelines are followed.
- If sedation is used there are risks of excessive sedation. The technologist or nurse monitors your vital signs to minimize this risk.
- Although the strong magnetic field is not harmful in itself, implanted medical devices that contain metal may malfunction or cause problems during an MRI exam.
- There is a very slight risk of an allergic reaction if contrast material is injected. Such reactions usually are mild and easily controlled by medication. If you experience allergic symptoms, a radiologist or other physician will be available for immediate assistance.
- Nephrogenic systemic fibrosis is currently a recognized, but rare, complication of MRI believed to be caused by the injection of high doses of gadolinium contrast material in patients with very poor kidney function.
A Word About Minimizing Radiation Exposure
Special care is taken during x-ray examinations to use the lowest radiation dose possible while producing the best images for evaluation. National and international radiology protection councils continually review and update the technique standards used by radiology professionals.
State-of-the-art x-ray systems have tightly controlled x-ray beams with significant filtration and dose control methods to minimize stray or scatter radiation. This ensures that those parts of a patient’s body not being imaged receive minimal radiation exposure.
Who interprets the results and how do I get them?
A radiologist, a physician specifically trained to supervise and interpret radiology examinations, will analyze the images and send a signed report to your primary care or referring physician, who will discuss the results with you.
Follow-up examinations are often necessary, and your doctor will explain the exact reason why another exam is requested. Sometimes a follow-up exam is done because a suspicious or questionable finding needs clarification with additional views or a special imaging technique. A follow-up examination may be necessary so that any change in a known abnormality can be detected over time. Follow-up examinations are sometimes the best way to see if treatment is working or if an abnormality is stable over time.
What will I experience during and after the procedure?
You will experience a slight pinprick and may feel a momentary burning if a local anesthesia is used to numb the joint area.
You may feel a fullness as the joint is filled and hear gurgling when the joint is moved.
If your arthrography exam involves MR imaging:
It is normal for the area of your body being imaged to feel slightly warm, but if it bothers you, notify the radiologist or technologist. It is important that you remain perfectly still while the images are being recorded, which is typically only a few seconds to a few minutes at a time. For some types of exams, you may be asked to hold your breath. You will know when images are being recorded because you will hear tapping or thumping sounds when the coils that generate the radiofrequency pulses are activated. You will be able to relax between imaging sequences, but will be asked to maintain your position without movement as much as possible.
You will usually be alone in the exam room during the MRI procedure. However, the technologist will be able to see, hear and speak with you at all times using a two-way intercom. Many MRI centers allow a friend or parent to stay in the room as long as they are also screened for safety in the magnetic environment.
You may be offered or you may request earplugs to reduce the noise of the MRI scanner, which produces loud thumping and humming noises during imaging. Children will be given appropriately sized earplugs or headphones during the exam. MRI scanners are air-conditioned and well-lit. Some scanners have music to help you pass the time.
When the contrast material is injected, it is normal to feel coolness and a flushing sensation for a minute or two. The intravenous needle may cause you some discomfort when it is inserted and once it is removed, you may experience some bruising. There is also a very small chance of irritation of your skin at the site of the IV tube insertion. Some patients may sense a metallic taste in their mouth after the contrast injection.
If you have not been sedated, no recovery period is necessary. You may resume your usual activities and normal diet immediately after the exam. A few patients experience side effects from the contrast material, including nausea and local pain. Very rarely, patients are allergic to the contrast material and experience hives, itchy eyes or other reactions. If you experience allergic symptoms, notify the technologist. A radiologist or other physician will be available for immediate assistance.
If you experience allergic symptoms, a radiologist or other physician will be available for immediate assistance.
After the examination, you may experience swelling and discomfort. You may apply ice to the joint to reduce swelling if it is bothersome. A mild over-the-counter analgesic can be taken for pain. These symptoms usually disappear after 48 hours. Contact your doctor if they persist after two days.
Vigorous exercise is not recommended for 12 hours after the exam.
How is the procedure performed?
This examination is usually done on an outpatient basis.
The patient is positioned on the examination table and x-rays are taken of the joint to be compared later with the arthrograms. If recent x-rays are available, the physician may choose to use these for reference.
Next, the skin around the joint is cleansed with antiseptic and a local anesthetic is injected into the area.
Your physician will numb the area with a local anesthetic.
The area where the needle is to be inserted will be sterilized and covered with a surgical drape.
A needle is then inserted into the joint. The radiologist, a physician specifically trained to supervise and interpret radiology examinations, will use a syringe to drain the joint fluid, which may be sent to a laboratory for analysis. Aspiration is typically performed when an infection is suspected.
The contrast material and sometimes air are injected into the joint space and the needle is removed. Air will not be used if the patient is undergoing MR arthrography. The patient will be asked to move the affected joint to distribute the contrast material throughout the space.
The conventional arthrography exam is usually completed within 30 minutes. Exams involving MRI may take more than one hour.
How does the procedure work?
X-rays are a form of radiation like light or radio waves. X-rays pass through most objects, including the body. Once it is carefully aimed at the part of the body being examined, an x-ray machine produces a small burst of radiation that passes through the body, recording an image on photographic film or a special digital image recording plate.
Different parts of the body absorb the x-rays in varying degrees. Dense bone absorbs much of the radiation while soft tissue, such as muscle, fat and organs, allow more of the x-rays to pass through them. As a result, bones appear white on the x-ray, soft tissue shows up in shades of gray and air appears black.
Until recently, x-ray images were maintained as hard film copy (much like a photographic negative). Today, most images are digital files that are stored electronically. These stored images are easily accessible and are frequently compared to current x-ray images for diagnosis and disease management.
Fluoroscopy uses a continuous or pulsed x-ray beam to create a sequence of images that are projected onto a fluorescent screen, or television-like monitor. When used with a contrast material, which clearly defines the area being examined by making it appear bright white, this special x-ray technique makes it possible for the physician to view joints or internal organs in motion. Still images are also captured and stored either on film or electronically on a computer.
Unlike conventional x-ray examinations and computed tomography (CT) scans, MRI does not depend on ionizing radiation. Instead, while in the magnet, radio waves redirect the axes of spinning protons, which are the nuclei of hydrogen atoms, in a strong magnetic field.
The magnetic field is produced by passing an electric current through wire coils in most MRI units. Other coils, located in the machine and in some cases, placed around the part of the body being imaged, send and receive radio waves, producing signals that are detected by the coils.
A computer then processes the signals and generates a series of images each of which shows a thin slice of the body. The images can then be studied from different angles by the interpreting radiologist.
Frequently, the differentiation of abnormal (diseased) tissue from normal tissues is better with MRI than with other imaging modalities such as x-ray, CT and ultrasound.
What does the equipment look like?
The equipment typically used for this examination consists of a radiographic table, an x-ray tube and a television-like monitor that is located in the examining room. Fluoroscopy, which converts x-rays into video images, is used to watch and guide progress of the procedure. The video is produced by the x-ray machine and an image intensifier that is suspended over a table on which the patient lies.
The traditional MRI unit is a large cylinder-shaped tube surrounded by a circular magnet. You will lie on a moveable examination table that slides into the center of the magnet.
Some MRI units, called short-bore systems, are designed so that the magnet does not completely surround you; others are open on the sides (open MRI). These units are especially helpful for examining patients who are fearful of being in a closed space and for those who are very obese. Newer open MRI units provide very high quality images for many types of exams; however, open MRI units with older magnets may not provide this same image quality. Certain types of exams cannot be performed using open MRI. For more information, consult your radiologist.
The computer workstation that processes the imaging information is located in a separate room from the scanner.
Other equipment necessary for performing arthrography include a variety of needles, syringes and a water-soluble contrast material.
How should I prepare?
No special preparation is necessary before arthrography. Food and fluid intake do not need to be restricted, unless a sedative will be given.
You should inform your physician of any medications you are taking and if you have any kidney problems or allergies, especially to iodinated contrast materials. Also inform your doctor about recent illnesses or other medical conditions.
Some MRI examinations may require the patient to receive an injection of contrast into the bloodstream. The radiologist or technologist may ask if you have allergies of any kind, such as allergy to iodine or x-ray contrast material, drugs, food, the environment, or asthma. However, the contrast material used for an MRI exam, called gadolinium, does not contain iodine and is less likely to cause side effects or an allergic reaction.
The radiologist should also know if you have any serious health problems or if you have recently had surgery. Some conditions, such as severe kidney disease, may prevent you from being given contrast material for having an MRI.
If you are scheduled to have MR or CT arthrography and have claustrophobia (fear of enclosed spaces) or anxiety, you may want to ask your physician about being sedated prior to the scheduled examination.
Jewelry and other accessories should be left at home if possible, or removed prior to the MRI scan. Because they can interfere with the magnetic field of the MRI unit, metal and electronic objects are not allowed in the exam room. These items include:
jewelry, watches, credit cards and hearing aids, all of which can be damaged.
pins, hairpins, metal zippers and similar metallic items, which can distort MRI images.
removable dental work.
pens, pocketknives and eyeglasses.
In most cases, an MRI exam is safe for patients with metal implants, except for a few types. People with the following implants cannot be scanned and should not enter the MRI scanning area unless explicitly instructed to do so by a radiologist or technologist who is aware of the presence of any of the following:
internal (implanted) defibrillator or pacemaker
cochlear (ear) implant
some types of clips used on brain aneurysms
some types of metal coils placed within blood vessels
You should tell the technologist if you have medical or electronic devices in your body, because they may interfere with the exam or potentially pose a risk, depending on their nature and the strength of the MRI magnet. Examples include but are not limited to:
artificial heart valves
implanted drug infusion ports
implanted electronic device, including a cardiac pacemaker
artificial limbs or metallic joint prostheses
implanted nerve stimulators
metal pins, screws, plates, stents or surgical staples
In general, metal objects used in orthopedic surgery pose no risk during MRI. However, a recently placed artificial joint may require the use of another imaging procedure. If there is any question of their presence, an x-ray may be taken to detect the presence of and identify any metal objects.
Patients who might have metal objects in certain parts of their bodies may also require an x-ray prior to an MRI. You should notify the technologist or radiologist of any shrapnel, bullets, or other pieces of metal which may be present in your body due to accidents. Dyes used in tattoos may contain iron and could heat up during MRI, but this is rarely a problem. Tooth fillings and braces usually are not affected by the magnetic field but they may distort images of the facial area or brain, so the radiologist should be aware of them.
You may be asked to remove some or all of your clothes and to wear a gown during the exam. You may also be asked to remove jewelry, removable dental appliances, eye glasses and any metal objects or clothing that might interfere with the x-ray images.
Women should always inform their physician and x-ray technologist if there is any possibility that they are pregnant. Many imaging tests are not performed during pregnancy so as not to expose the fetus to radiation. If an x-ray is necessary, precautions will be taken to minimize radiation exposure to the baby. See the Safety page for more information about pregnancy and x-rays.
Though MRI does not use ionizing radiation, women should still inform their physician and technologist if they may be pregnant.
Children younger than teenagers may need to be sedated in order to hold still for the procedure. Parents should ask about this beforehand and be made aware of food and drink restrictions that may be needed prior to sedation.
You should plan to have a relative or friend drive you home after your procedure.