KNEE REPLACEMENT DIAGNOSIS PREPARATION

knee replacement diagnosis preparation
Patient history
The first part of a diagnostic interview for knee pain is the careful taking of the patient’s history. The doctor will ask not only for a general medical history, but also about the patient’s occupation, exercise habits, past injuries to the knee, and any gait-related problems. The doctor will also ask detailed questions about the patient's ability to move or flex the knee; whether specific movements or activities make the pain worse; whether the pain is sharp or dull; its location in the knee; whether the knee ever buckles or catches; and whether there are clicking or popping sounds inside the joint.

Diagnostic tests
PHYSICAL EXAMINATION OF THE KNEE.
Following the history, the doctor will examine the knee itself. The knee will be checked for swelling, reddening, bruises, breaks in the skin, lumps, or other unusual features while the patient is standing. The doctor will also make note of the patient’s posture, including whether the patient is bowlegged or knock-kneed. The patient may be asked to walk back and forth so that the doctor can check for gait abnormalities.

In the second part of the physical examination, the patient lies on an examining table while the doctor palpates (feels) the structures of the knee and evaluates the strength or tightness of the tendons and ligaments. The patient may be asked to flex one knee and straighten the leg or turn the knee inward and outward so that the doctor can measure the range of motion in the joint. The doctor will also ask the patient to lie still while he or she moves the knee in different directions.

IMAGING STUDIES.
The doctor will order one or more imaging studies in order to narrow the diagnosis. A radiograph or x ray is the most common, but is chiefly useful in showing fractures or other damage to bony structures. X-ray studies are usually supplemented by other imaging techniques in diagnosing knee disorders. A computed tomography, or CAT scan, which is a specialized type of x ray that uses computers to generate three-dimensional images of the knee joint, is often helpful in evaluating malformations of the joint. Magnetic resonance imaging (MRI) uses a large magnet, radio waves, and a computer to generate images of the knee joint. The advantage of an MRI is that it reveals injuries to ligaments, tendons, and menisci as well as damage to bony structures.

ASPIRATION.
Aspiration is a procedure in which fluid is withdrawn from the knee joint by a needle and sent to a laboratory for analysis. It is done to check for infection in the joint and to draw off fluid that is causing pain. Aspiration is most commonly done when the knee has swelled up suddenly, but may be performed at any time. Blood in the fluid usually indicates a fracture or torn ligament; the presence of bacteria indicates infection; the presence of uric acid crystals indicates gout. Clear, straw-colored fluid suggests osteoarthritis.

ARTHROSCOPY.
Arthroscopy can be used to treat knee problems as well as diagnose them. An arthroscope consists of a miniature camera and light source mounted on a flexible fiberoptic tube. It allows the surgeon to look into the knee joint. To perform an arthroscopy, the surgeon will make two to four small incisions known as ports. One port is used to insert the arthroscope; the second port allows insertion of miniaturized surgical instruments; the other ports drain fluid from the knee. Sterile saline fluid is pumped into the knee to enlarge the joint space and make it easier for the surgeon to view the knee structures and to cut, smooth, or repair damaged tissue.

Preoperative preparation
Knee replacement surgery requires extensive and detailed preparation on the patient’s part because it affects so many aspects of life.

LEGAL AND FINANCIAL CONSIDERATIONS.
In the United States, physicians and hospitals are required to verify the patient’s insurance benefits before surgery and to obtain precertification from the patient’s insurer or from Medicare. Without health insurance, the total cost of a knee replacement as of early 2003 can run as high as $38,000. In addition to insurance documentation, patients are legally required to sign an informed consent form prior to surgery. Informed consent signifies that the patient is a knowledgeable participant in making healthcare decisions. The doctor will discuss all of the following with the patient before he or she signs the form: the nature of the surgery; reasonable alternatives to the surgery; and the risks, benefits, and uncertainties of each option. Informed consent also requires the doctor to make sure that the patient understands the information that has been given.

MEDICAL CONSIDERATIONS.
Patients are asked to do the following in preparation for knee replacement surgery:
• Get in shape physically by doing exercises to strengthen or increase flexibility in the knee joint. Specific exercises are described in the books listed below. Many clinics and hospitals also distribute illustrated pamphlets of preoperation exercises.
• Lose weight if the surgeon recommends it.
• Quit smoking. Smoking weakens the cardiovascular system and increases the risks that the patient will have breathing difficulties under anesthesia.
• Make donations of one’s own blood for storage in case a transfusion is necessary during surgery. This procedure is known as autologous blood donation; it has the advantage of avoiding the risk of transfusion reactions or transmission of diseases from infected blood donors.
• Check the skin of the knee and lower leg for external infection or irritation, and check the lower leg for signs of swelling. If either is noted, the surgeon should be contacted for instructions about preparing the skin for the operation.
• Have necessary dental work completed before the operation. This precaution is necessary because small numbers of bacteria enter the bloodstream whenever a dentist performs any procedure that causes the gums to bleed. Bacteria from the mouth can be carried to the knee area and cause an infection.
• Discontinue taking birth control pills and any anti-inflammatory medications (aspirin or NSAIDs) two weeks before surgery. Most doctors also recommend discontinuing any alternative herbal preparations at this time, as some of them interact with anesthetics and pain medications.

LIFESTYLE CHANGES.
Knee replacement surgery requires a long period of recovery at home after leaving the hospital. Since the patient’s physical mobility will be limited, he or she should do the following before the operation:
• Arrange for leave from work, help at home, help with driving, and similar tasks and commitments.
• Obtain a handicapped parking permit.
• Check the house or apartment thoroughly for needed adjustments to furniture, appliances, lighting, and personal conveniences. People recovering from knee replacement surgery must avoid kneeling, and minimize bending, squatting, and any risk of falling. There are several good guides available that describe household safety and comfort considerations in detail.
• Stock up on nonperishable groceries, cleaning supplies, and similar items in order to minimize shopping.
• Have a supply of easy - care clothing with elastic waistbands and simple fasteners in front rather than complicated ties or buttons in the back. Women may find knit dresses that pull on over the head or wraparound skirts easier to put on than slacks or skirts that must be pulled up over the knees. Shoes should be slip-ons or fastened with Velcro.

Many hospitals and clinics now have preop classes for patients scheduled for knee replacement surgery. These classes answer questions about the operation and what to expect during recovery, but in addition they provide an opportunity for patients to share concerns and experiences. Studies indicate that patients who have attended preop classes are less anxious before surgery and generally recover more rapidly.