Author: Marsha Owens
3 downloads 0 Views 499KB Size


Knee replacement, or knee arthroplasty, is a surgical procedure to replace the weight-bearing surfaces of the knee joint to relieve the pain and disability of osteoarthritis. It may be performed for other knee diseases such as rheumatoid arthritis and psoriatic arthritis. In patients with severe deformity from advanced rheumatoid arthritis, trauma, or long standing osteoarthritis, the surgery may be more complicated and carry higher risk. Osteoporosis does not typically cause knee pain, deformity, or inflammation and is not a reason to perform knee replacement.

Overview of Total Knee Replacement If your knee is severely damaged by arthritis or injury, it may be hard for you to perform simple activities, such as walking or climbing stairs. You may even begin to feel pain while you are sitting or lying down. If nonsurgical treatments like medications and using walking supports are no longer helpful, you may want to consider total knee replacement surgery. Joint replacement surgery is a safe and effective procedure to relieve pain, correct leg deformity, and help you resume normal activities. Knee replacement surgery was first performed in 1968. Since then, improvements in surgical materials and techniques have greatly increased its effectiveness. Total knee replacements are one of the most successful procedures in all of medicine. According to the Agency for Healthcare Research and Quality, more than 600,000 knee replacements are performed each year in the United States. Whether you have just begun exploring treatment options or have already decided to have total knee replacement surgery, this article will help you understand more about this valuable procedure. Major causes of knee pain include:    

Meniscus tears Cartilage defects Ligament tears Osteoarthritis

Ideal Candidates for Total Knee Replacement The decision to have total knee replacement surgery should be a cooperative one between you, your family, your family physician, and your orthopaedic surgeon. Your physician may refer you to an orthopaedic surgeon for a thorough evaluation to determine if you might benefit from this surgery. There are no absolute age or weight restrictions for total knee replacement surgery. Recommendations for surgery are based on a patient's pain and disability, not age. Most patients who undergo total knee replacement are age 50 to 80, but orthopaedic surgeons evaluate patients individually. Total knee replacements have been performed successfully at all ages, from the young teenager with juvenile arthritis to the elderly patient with degenerative arthritis.

Page 2 of 12

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

When Surgery Is Recommended: 

   

Severe knee pain or stiffness that limits your everyday activities, including walking, climbing stairs, and getting in and out of chairs. You may find it hard to walk more than a few blocks without significant pain and you may need to use a cane or walker. Moderate or severe knee pain while resting, either day or night. Chronic knee inflammation and swelling that does not improve with rest or medications Knee deformity — a bowing in or out of your knee Failure to substantially improve with other treatments such as anti-inflammatory medications, cortisone injections, lubricating injections, physical therapy, or other surgeries

You may submit records, x-rays and your doctor’s recommendation. Our orthopedic surgeon can review them and submit a free online consultation. However, before you travel it is best to determine that you are a candidate for the surgery by visiting your local orthopedic surgeon first. Otherwise it is important for you to submit as much information as possible.

Total Knee Replacement Surgery A knee replacement (also called knee arthroplasty) might be more accurately termed a knee "resurfacing" because only the surface of the bones are actually replaced. There are Four Basic Steps To a Knee Replacement Procedure:    

Prepare the bone. The damaged cartilage surfaces at the ends of the femur and tibia are removed along with a small amount of underlying bone. Position the metal implants. The removed cartilage and bone is replaced with metal components that recreate the surface of the joint. These metal parts may be cemented or "press-fit" into the bone. Resurface the patella. The undersurface of the patella (kneecap) is cut and resurfaced with a plastic button. Some surgeons do not resurface the patella, depending upon the case. Insert a spacer. A medical-grade plastic spacer is inserted between the metal components to create a smooth gliding surface.

Orthopedic Evaluation Your orthopaedic surgeon will review the results of your evaluation with you and discuss whether total knee replacement is the best method to relieve your pain and improve your function. Other treatment options — including medications, injections, physical therapy, or other types of surgery — will also be considered and discussed. In addition, your orthopaedic surgeon will explain the potential risks and complications of total knee replacement, including those related to the surgery itself and those that can occur over time after your surgery. An Evaluation With an Orthopaedic Surgeon Consists of Several Components:    

Page 3 of 12

A medical history. Your orthopaedic surgeon will gather information about your general health and ask you about the extent of your knee pain and your ability to function. A physical examination. This will assess knee motion, stability, strength, and overall leg alignment. X-rays. These images help to determine the extent of damage and deformity in your knee.. Other tests. Occasionally blood tests, or advanced imaging such as a magnetic resonance imaging (MRI) scan, may be needed to determine the condition of the bone and soft tissues of your knee.

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Realistic Expectations An important factor in deciding whether to have total knee replacement surgery is understanding what the procedure can and cannot do. More than 90% of people who have total knee replacement surgery experience a dramatic reduction of knee pain and a significant improvement in the ability to perform common activities of daily living. But total knee replacement will not allow you to do more than you could before you developed arthritis. With normal use and activity, every knee replacement implant begins to wear in its plastic spacer. Excessive activity or weight may speed up this normal wear and may cause the knee replacement to loosen and become painful. Therefore, most surgeons advise against high-impact activities such as running, jogging, jumping, or other high-impact sports for the rest of your life after surgery. Realistic activities following total knee replacement include unlimited walking, swimming, golf, driving, light hiking, biking, ballroom dancing, and other low-impact sports. With appropriate activity modification, knee replacements can last for many years.

Preparing for Knee Surgery Medical Evaluation If you decide to have total knee replacement surgery, your orthopaedic surgeon may ask you to schedule a complete physical examination with your family physician several weeks before the operation. This is needed to make sure you are healthy enough to have the surgery and complete the recovery process. Many patients with chronic medical conditions, like heart disease, may also be evaluated by a specialist, such as a cardiologist, before the surgery. Tests Several tests, such as blood and urine samples, and an electrocardiogram, may be needed to help your orthopaedic surgeon plan your surgery. Medication Tell your orthopaedic surgeon about the medications you are taking. He or she will tell you which medications you should stop taking and which you should continue to take before surgery. Dental Evaluation Although the incidence of infection after knee replacement is very low, an infection can occur if bacteria enter your bloodstream. To reduce the risk of infection, major dental procedures (such as tooth extractions and periodontal work) should be completed before your total knee replacement surgery. Urinary Evaluation People with a history of recent or frequent urinary infections should have a urological evaluation before surgery. Older men with prostate disease should consider completing required treatment before undertaking knee replacement surgery. Social Planning Although you will be able to walk on crutches or a walker soon after surgery, you will need help for several weeks with such tasks as cooking, shopping, bathing, and doing laundry. If you live alone, your orthopaedic surgeon's office, a social worker, or a discharge planner at the hospital can help you make advance arrangements to have someone assist you at home. They also can help you arrange for a short stay in an extended care facility during your recovery, if this option works best for you. Page 4 of 12

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Home Planning Several modifications can make your home easier to navigate during your recovery. The following items may help with daily activities:       

Safety bars or a secure handrail in your shower or bath Secure handrails along your stairways A stable chair for your early recovery with a firm seat cushion (and a height of 18 to 20 inches), a firm back, two arms, and a footstool for intermittent leg elevation A toilet seat riser with arms, if you have a low toilet A stable shower bench or chair for bathing Removing all loose carpets and cords A temporary living space on the same floor because walking up or down stairs will be more difficult during your early recovery

Knee Surgery You will be admitted to the hospital on the day of your surgery. Anesthesia After admission, you will be evaluated by a member of the anesthesia team. The most common types of anesthesia are general anesthesia (you are put to sleep) or spinal, epidural, or regional nerve block anesthesia (you are awake but your body is numb from the waist down). The anesthesia team, with your input, will determine which type of anesthesia will be best for you. Procedure The procedure itself takes approximately 1 to 2 hours. Your orthopaedic surgeon will remove the damaged cartilage and bone, and then position the new metal and plastic implants to restore the alignment and function of your knee.

Hospital Stay Your knee replacement package includes 3 – 4 night hospital stay in a private VIP hospital suite that includes wifi internet.

Pain Management After surgery, you will feel some pain, but your surgeon and nurses will provide medication to make you feel as comfortable as possible. Pain management is an important part of your recovery. Walking and knee movement will begin soon after surgery, and when you feel less pain, you can start moving sooner and get your strength back more quickly. Talk with your surgeon if postoperative pain becomes a problem.

Blood Clot Prevention Your orthopaedic surgeon may prescribe one or more measures to prevent blood clots and decrease leg swelling. These may include special support hose, inflatable leg coverings (compression boots), and blood thinners. Foot and ankle movement also is encouraged immediately following surgery to increase blood flow in your leg muscles to help prevent leg swelling and blood clots.

Page 5 of 12

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Physical Therapy Most patients begin exercising their knee the day after surgery. A physical therapist will teach you specific exercises to strengthen your leg and restore knee movement to allow walking and other normal daily activities soon after your surgery. To restore movement in your knee and leg, your surgeon may use a knee support that slowly moves your knee while you are in bed. The device, called a continuous passive motion (CPM) exercise machine, decreases leg swelling by elevating your leg and improves your blood circulation by moving the muscles of your leg.

Preventing Pneumonia It is common for patients to have shallow breathing in the early postoperative period. This is usually due to the effects of anesthesia, pain medications, and increased time spent in bed. This shallow breathing can lead to a partial collapse of the lungs (termed "atelectasis") which can make patients susceptible to pneumonia. To help prevent this, it is important to take frequent deep breaths. Your nurse may provide a simple breathing apparatus called a spirometer to encourage you to take deep breaths.

Recovery The success of your surgery will depend largely on how well you follow your orthopaedic surgeon's instructions at home during the first few weeks after surgery.

Wound Care You will have stitches or staples running along your wound or a suture beneath your skin on the front of your knee. The stitches or staples will be removed several weeks after surgery. A suture beneath your skin will not require removal. Avoid soaking the wound in water until it has thoroughly sealed and dried. You may continue to bandage the wound to prevent irritation from clothing or support stockings.

Diet Some loss of appetite is common for several weeks after surgery. A balanced diet, often with an iron supplement, is important to help your wound heal and to restore muscle strength.

Activity Exercise is a critical component of home care, particularly during the first few weeks after surgery. You should be able to resume most normal activities of daily living within 3 to 6 weeks following surgery. Some pain with activity and at night is common for several weeks after surgery. Your activity program should include:   

A graduated walking program to slowly increase your mobility, initially in your home and later outside Resuming other normal household activities, such as sitting, standing, and climbing stairs Specific exercises several times a day to restore movement and strengthen your knee. You probably will be able to perform the exercises without help, but you may have a physical therapist help you at home or in a therapy center the first few weeks after surgery.

You will most likely be able to resume driving when your knee bends enough that you can enter and sit comfortably in your car, and when your muscle control provides adequate reaction time for braking and acceleration. Most people resume driving approximately 4 to 6 weeks after surgery.

Page 6 of 12

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Knee Replacement Outcome Improvement of knee motion is a goal of total knee replacement, but restoration of full motion is uncommon. The motion of your knee replacement after surgery can be predicted by the range of motion you have in your knee before surgery. Most patients can expect to be able to almost fully straighten the replaced knee and to bend the knee sufficiently to climb stairs and get in and out of a car. Kneeling is sometimes uncomfortable, but it is not harmful. Most people feel some numbness in the skin around your incision. You also may feel some stiffness, particularly with excessive bending activities. Most people also feel or hear some clicking of the metal and plastic with knee bending or walking. This is a normal. These differences often diminish with time and most patients find them to be tolerable when compared with the pain and limited function they experienced prior to surgery. Your new knee may activate metal detectors required for security in airports and some buildings. Tell the security agent about your knee replacement if the alarm is activated.

Protecting Your Knee Replacement After surgery, make sure you also do the following:    

Participate in regular light exercise programs to maintain proper strength and mobility of your new knee Take special precautions to avoid falls and injuries. If you break a bone in your leg, you may require more surgery Make sure your dentist knows that you have a knee replacement. You should be given antibiotics before all dental surgery for the rest of your life See your orthopaedic surgeon periodically for a routine follow-up examination and x-rays, usually once a year

Extending the Life of Your Knee Implant Currently, more than 90% of modern total knee replacements are still functioning well 15 years after the surgery. Following your orthopaedic surgeon's instructions after surgery and taking care to protect your knee replacement and your general health are important ways you can contribute to the final success of your surgery.

Blood Clot Prevention Follow your orthopaedic surgeon's instructions carefully to reduce the risk of blood clots developing during the first several weeks of your recovery. He or she may recommend that you continue taking the blood thinning medication you started in the hospital. Notify your doctor immediately if you develop any of the following warning signs. Warning signs of blood clots. The warning signs of possible blood clots in your leg include:   

Increasing pain in your calf Tenderness or redness above or below your knee Increasing swelling in your calf, ankle, and foot

Warning signs of pulmonary embolism. The warning signs that a blood clot has traveled to your lung include:   

Page 7 of 12

Sudden shortness of breath Sudden onset of chest pain Localized chest pain with coughing

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Preventing Infection A common cause of infection following total knee replacement surgery is from bacteria that enter the bloodstream during dental procedures, urinary tract infections, or skin infections. These bacteria can lodge around your knee replacement and cause an infection. After your knee replacement, you must take preventive antibiotics before dental or surgical procedures that could allow bacteria to enter your bloodstream. Warning signs of infection. Notify your doctor immediately if you develop any of the following signs of a possible knee replacement infection:     

Persistent fever (higher than 100°F orally) Shaking chills Increasing redness, tenderness, or swelling of the knee wound Drainage from the knee wound Increasing knee pain with both activity and rest

Avoiding Falls A fall during the first few weeks after surgery can damage your new knee and may result in a need for further surgery. Stairs are a particular hazard until your knee is strong and mobile. You should use a cane, crutches, a walker, hand rails, or have someone to help you until you have improved your balance, flexibility, and strength. Your surgeon and physical therapist will help you decide what assistive aides will be required following surgery and when those aides can safely be discontinued.

Words To Know The following are health and medical definitions of terms that appear in the Knee Joint Replacement article. Antibiotic: A drug used to treat infections caused by bacteria and other microorganisms. Originally, an antibiotic was a substance produced by one microorganism that selectively inhibits the growth of another. Synthetic antibiotics, usually chemically related to natural antibiotics, have since been produced that accomplish comparable tasks. Artery: A vessel that carries blood high in oxygen content away from the heart to the farthest reaches of the body. Since blood in arteries is usually full of oxygen, the hemoglobin in the red blood cells is oxygenated. The resultant form of hemoglobin (oxyhemoglobin) is what makes arterial blood look bright red. Arthritis: Inflammation of a joint. When joints are inflamed they can develop stiffness, warmth, swelling, redness and pain. There are over 100 types of arthritis. Arthrocentesis: Joint aspiration, a procedure whereby a sterile needle and syringe are used to drain fluid from a joint. This is usually done as an office procedure or at the bedside in the hospital. Bacteria: Single-celled microorganisms which can exist either as independent (free-living) organisms or as parasites (dependent upon another organism for life). Blood clot: Blood that has been converted from a liquid to a solid state. Also called a thrombus. Blood clots: Blood that has been converted from a liquid to a solid state. Also called a thrombus. Chronic: This important term in medicine comes from the Greek chronos, time and means lasting a long time. Page 8 of 12

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Deep vein thrombosis: A blood clot (thrombus) in a deep vein in the thigh or leg. The clot can break off as an embolus and make its way to the lung, where it can cause respiratory distress and respiratory failure. Diagnosis: 1 The nature of a disease; the identification of an illness. 2 A conclusion or decision reached by diagnosis. The diagnosis is rabies. 3 The identification of any problem. The diagnosis was a plugged IV. Doppler ultrasound: A form of ultrasound that can detect and measure blood flow. Doppler ultrasound depends on the Doppler effect, a change in the frequency of a wave resulting here from the motion of a reflector, the red blood cell. Embolism: The obstruction of a blood vessel by a foreign substance or a blood clot blocking the vessel. Something travels through the bloodstream, lodges in a vessel and plugs it. Emergency department: The department of a hospital responsible for the provision of medical and surgical care to patients arriving at the hospital in need of immediate care. Emergency department personnel may also respond to certain situations within the hospital such cardiac arrests. Enoxaparin: A low-molecular-weight version of heparin which acts like heparin as an anticoagulant (anti-clotting) medication. Enoxaparin is used to prevent thromboembolic complications (clots that travel from their site of origin through the blood stream to clog up another vessel). Enoxaparin is also used in the early treatment of blood clots in the lungs (pulmonary embolisms). Femur: The femur is the bone in the leg that extends from the hip to the knee. Fever: Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.). Fracture: A break in bone or cartilage. Although usually the result of trauma, a fracture can be caused by an acquired disease of bone such as osteoporosis or by abnormal formation of bone in a disease such as osteogenesis imperfecta ("brittle bone disease"). Fractures are classified according to their character and location as, for example, a greenstick fracture of the radius. Gait: A manner of walking. Observation of the gait can provide clues to a number of diagnoses including Parkinson disease, cerebral palsy, congenital dislocation of the hip, and stroke. Heparin: An anticoagulant (anti-clotting) medication. Heparin is useful in preventing thromboembolic complications (clots that travel from their site of origin through the blood stream to clog up another vessel). Heparin is also used in the early treatment of blood clots in the lungs (pulmonary embolisms). Infection: The growth of a parasitic organism within the body. (A parasitic organism is one that lives on or in another organism and draws its nourishment therefrom.) A person with an infection has another organism (a "germ") growing within him, drawing its nourishment from the person. Injury: Harm or hurt. The term "injury" may be applied in medicine to damage inflicted upon oneself as in a hamstring injury or by an external agent on as in a cold injury. The injury may be accidental or deliberate, as with a needlestick injury. The term "injury" may be synonymous (depending on the context) with a wound or with trauma. Joint: A joint is the area where two bones are attached for the purpose of motion of body parts. A joint is usually formed of fibrous connective tissue and cartilage. An articulation or an arthrosis is the same as a joint. Knee: The knee is a joint which has three parts. The thigh bone (the femur) meets the large shin bone (the tibia) to form the main knee joint. This joint has an inner (medial) and an outer (lateral) compartment. The kneecap (the patella) joins the femur to form a third joint, called the patellofemoral joint. The patella protects the front of the knee joint.

Page 9 of 12

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Knee joint: The knee joint has three parts. The thigh bone (the femur) meets the large shin bone (the tibia) to form the main knee joint. This joint has an inner (medial) and an outer (lateral) compartment. The kneecap (the patella) joins the femur to form a third joint, called the patellofemoral joint. The patella protects the front of the knee joint. Leg: In popular usage, the leg extends from the top of the thigh down to the foot. However, in medical terminology, the leg refers to the portion of the lower extremity from the knee to the ankle. Lower leg: The lower leg is the bottom segment of the leg: the part below the knee. Numb: Numb, or numbness is a loss of the sensation of feeling in an area of the body. Numbness results from damage to, or impaired function of, the nerves that supply the affected area. The function of the nerves may be impaired by numerous causes including some chronic diseases (diabetes mellitus, thyroid disease, migraine), trauma, toxins, decreased blood supply due to atherosclerosis or other conditions, electrolyte imbalances, and pressure on the spinal nerves from herniated discs or other diseases of the spine. Orthopedist: An orthopaedic surgeon, orthopaedics being the branch of surgery broadly concerned with the skeletal system (bones). Orthopedics is how this field of surgery is listed under Physicians & Surgeons in the telephone Yellow Pages in Jacksonville, Florida. This spelling is quite common today. But it is incorrect, erroneous, flat out wrong. Orthopedics would relate the term to the foot because in Latin pedis means foot. Orthopaedics is not merely old-fashioned. It is the correct spelling. What was meant by the term orthopaedics when it was devised goes back to its roots: ortho-, straight + the Greek paes, child = the practice, literally, of straightening the child. If the child had a crooked spine (scoliosis), it was the job of the orthopaedist to straighten the child, not just the child's foot. That is why there is no American Academy of Orthopedic Surgery but there is an American Academy of Orthopaedic Surgery. And that is also why orthopaedists look after broken bones. Osteoarthritis: A type of arthritis caused by inflammation, breakdown, and eventual loss of cartilage in the joints. Also known as degenerative arthritis. Pain: An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation. Pain may be contained to a discrete area, as in an injury, or it can be more diffuse, as in disorders like fibromyalgia. Pain is mediated by specific nerve fibers that carry the pain impulses to the brain where their conscious appreciation may be modified by many factors. Paresis: 1 Incomplete paralysis. 2 A form of neurosyphilis (syphilis affecting the central nervous system -- the brain and spinal cord). Also known as general paresis, neurolues, acute syphilitic meningitis, meningovascular syphilis, tabes dorsalis, and the great pox. First recognized in Europe as a distinct epidemic in Naples in the late 1400s coincident with the invasion of Naples by the French. The dispersal of the debauched French mercenary army throughout Western Europe led to the frighteningly fast spread of the new disease. Paresthesia: An abnormal sensation of the skin, such as numbness, tingling, pricking, burning, or creeping on the skin that has no objective cause. Paresthesia is the usual American spelling and paraesthesia the preferred English spelling. Physical therapy: A branch of rehabilitative health that uses specially designed exercises and equipment to help patients regain or improve their physical abilities. Physical therapists work with many types of patients, from infants born with musculoskeletal birth defects, to adults suffering from sciatica or the after- effects of injury, to elderly post-stroke patients. Popliteal: Refers to the back of the knee. Prosthetic: Referring to a prosthesis, an artificial substitute or replacement of a part of the body such as a tooth, eye, a facial bone, the palate, a hip, a knee or another joint, the leg, an arm, etc. A prosthesis is designed for functional or cosmetic reasons or both. Page 10 of 12

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Pulmonary: Having to do with the lungs. (The word comes from the Latin pulmo for lung). Pulmonary embolism: The obstruction of the pulmonary artery or a branch of it leading to the lungs by a blood clot, usually from the leg, or foreign material causing sudden closure of the vessel. (Embolus is from the Greek "embolos" meaning plug.) Range of motion: The range through which a joint can be moved, usually its range of flexion and extension. Due to an injury, the knee may for example lack 10 degrees of full extension. Rehabilitation: The process of restoration of skills by a person who has had an illness or injury so as to regain maximum selfsufficiency and function in a normal or as near normal manner as possible. For example, rehabilitation after a stroke may help the patient walk again and speak clearly again. Rheumatoid arthritis: An autoimmune disease which causes chronic inflammation of the joints, the tissue around the joints, as well as other organs in the body. Autoimmune diseases occur when the body tissues are mistakenly attacked by its own immune system. The immune system is a complex organization of cells and antibodies designed normally to "seek and destroy" invaders of the body, particularly infections. Patients with these diseases have antibodies in their blood which target their own body tissues, where they can be associated with inflammation. Because it can affect multiple other organs of the body, rheumatoid arthritis is referred to as a systemic illness and is sometimes called rheumatoid disease. While rheumatoid arthritis is a chronic illness (meaning it can last for years) patients may experience long periods without symptoms. Surgery: The word "surgery" has multiple meanings. It is the branch of medicine concerned with diseases and conditions which require or are amenable to operative procedures. Surgery is the work done by a surgeon. By analogy, the work of an editor wielding his pen as a scalpel is s form of surgery. A surgery in England (and some other countries) is a physician's or dentist's office. Syringe: A device used in medicine to inject fluid into or withdraw fluid from the body. Medical syringes consist of a needle attached to a hollow cylinder that is fitted with a sliding plunger. The downward movement of the plunger injects fluid; upward movement withdraws fluid. Temple: An area just behind and to the side of the forehead and the eye, above the side of the check bone (the zygomatic arch) and in front of the ear. Therapy: The treatment of disease. Thigh: The thigh extends from the hip to the knee. The thigh has only one bone, the femur which is the largest bone in the human body. Thigh bone: The thigh bone in anatomy is called the "femur." Whichever term you care to use -- thigh bone or femur, it is the bone in the leg that extends from the hip to the knee. Thrombosis: The formation or presence of a blood clot in a blood vessel. The vessel may be any vein or artery as, for example, in a deep vein thrombosis or a coronary (artery) thrombosis. The clot itself is termed a thrombus. If the clot breaks loose and travels through the bloodstream, it is a thromboembolism. Thrombosis, thrombus, and the prefix thrombo- all come from the Greek thrombos meaning a lump or clump, or a curd or clot of milk. See entries also to: Cavernous sinus thrombosis; Renal vein thrombosis. And see: Deep Vein Thrombosis and Pulmonary Embolism. Total knee replacement: A surgical procedure in which damaged parts of the knee joint are replaced with artifical parts.

Page 11 of 12

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Ultrasound: High-frequency sound waves. Ultrasound waves can be bounced off of tissues using special devices. The echoes are then converted into a picture called a sonogram. Ultrasound imaging, referred to as ultrasonography, allows physicians and patients to get an inside view of soft tissues and body cavities, without using invasive techniques. Ultrasound is often used to examine a fetus during pregnancy. There is no convincing evidence for any danger from ultrasound during pregnancy. Vein: A blood vessel that carries blood low in oxygen content from the body back to the heart. The deoxygenated form of hemoglobin (deoxyhemoglobin) in venous blood makes it appear dark. Veins are part of the afferent wing of the circulatory system which returns blood to the heart. X-ray: 1. High-energy radiation with waves shorter than those of visible light. X-rays possess the properties of penetrating most substances (to varying extents), of acting on a photographic film or plate (permitting radiography), and of causing a fluorescent screen to give off light (permitting fluoroscopy). In low doses X-rays are used for making images that help to diagnose disease, and in high doses to treat cancer. Formerly called a Roentgen ray. 2. An image obtained by means of X-rays.

Page 12 of 12

Total Knee Replacement Surgery Overview

ThaiMed International LTD.

Suggest Documents