Research Korner: Total Knee Replacement Surgery

TOTAL KNEE REPLACEMENT SURGERY   Introduction               People undergo total knee replacement when arthritis or injury erodes the joint's natural cushioning to the point where it's hard to walk even short distances without severe pain.               Knee replacements now cost the NHS more each year than total hip replacements. An ageing population and an increase in obesity-related conditions are placing an increasing strain on NHS resources, with the number of knee replacements performed rising by 15 per cent last year from 59,391 to 68,300. Doctors predict that by 2010, such operations could cost the NHS almost pounds 1 billion per year.               The average age for a total knee replacement is 70. Osteoarthritis, one of the four most common problems linked to obesity, is the major cause of surgery. Overweight and obese people are 24 per cent more likely to require knee surgery. About 68,300 knee replacements were performed in the UK in 2002, costing the NHS in the region of pounds 375 million (2003).               There are more replacement operations performed on the knee than any other joint in the body: more than 600 000 total knee replacements are performed each year globally. The annual total global knee market is estimated to be worth $2 billion ().               Total knee replacement, which is defined as the surgical insertion of a hinged artificial joint, relieves pain and restores motion to a knee which is affected by arthritis or injury. In a standard total knee replacement, the damaged areas of the thighbone, shinbone and kneecap are removed and replaced with prostheses.   The diseased bone surfaces are removed and a two-piece metallic hinge is cemented into the cavities of the upper and lower leg bones (femur and tibia). After surgery, the knee is held in position, usually with a plaster cast. The ends of the remaining bones are smoothed and reshaped to accommodate the prostheses. Pieces of the artificial knee are typically held in place with bone cement or plaster cast. Physical therapy includes exercise and whirlpool baths. The mobility and range of motion of the joint increase slowly.             It is healing of the muscle and tendon that causes much of the pain during recovery, as clients must stretch those injured parts in order to regain knee motion. Despite excruciating pain and decreased mobility, many people with knees damaged by arthritis put off joint-replacement surgery out of fear and uncertainty.   Body   The largest joint in the body, the knee joint is formed where the lower part of the thighbone (femur) joins the upper part of the shinbone (tibia) and the kneecap (patella). Shock-absorbing cartilage covers the surfaces where these three bones touch ( 2000). In a normal knee, the bone surfaces that come together at the joint-thighbone, shinbone and kneecap--are smooth and hard. A cushioning layer of tissue (cartilage) prevents direct contact between these bones. When the cartilage is damaged, these bones rub together, causing friction, pain and, eventually, deterioration of the bone surfaces (2004). As it is the largest joint in the body, it is also prone to pain and loss of function and stability, which therefore requires surgery to be done.                         Remedies included not using the affected joint but more recently researchers have found some substances such as glucosamine and chondroitin, as well as apple pectin which have in some cases been able to stimulate regeneration of the cartilage. But often the recommendation consists of losing weight, use of pain killers from aspirin to ibuprophen, and the cox 2 inhibitors, one of which (Vioxx) got into trouble recently because they found it enhanced heart problems. Injecting a gel substitute into the knees has helped but often the relief lasts for only about six months.   The ultimate remedy by the doctors is total knee replacement. What this means is that they open up the knee, cut off or shave the ends of the leg bone and the thigh bone and cap them with a metal and hard plastic that allows articulation of the knees. The main benefit is the removal of pain.   There are actually three reasons the doctor (an orthopedic surgeon) will recommend an artificial knee. These are: 1) to relieve pain 2) to restore function and 3) to achieve stability. As the arthritic knee becomes more painful, the patient will use it less. Function, therefore, is lost. As the arthritic knee continues to deform, the patient will feel that the joint is wobbly or unstable.               The most common indication for total knee replacement is osteoarthritis, or degenerative joint disease. The end stage of osteoarthritis is wearing out of cartilage (smooth, gliding bone ends) resulting in bone-to-bone contact in diseased joints. It is progressive and becomes increasingly painful as the cartilage erodes. Younger people who get knee replacements have damaged their joints by trauma (accidents that destroy joint surfaces), infection, cancer or tumor, and inflammatory conditions such as rheumatoid arthritis.               Painful knees are the most common manifestation of osteoarthritis, while osteoarthritis in turn is the most common of the different kinds of arthritis. About 60 percent or more of arthritis sufferers have this form. But this is not the most difficult. Rheumatoid arthritis is often deforming and most painful of the hundred or so forms of arthritis.   Osteoarthritis can found in all weight-bearing joints such as the spinal column, the hips, the ankles, and the knees. Osteoarthritis in the knees is basically the loss of cartilage between the bones of the knees (2004). What causes it is still not clear. As the cartilage is eroded in the knees, standing or walking becomes more and more painful as the knee bones grind against each other without a cushion. An accident or high-impact sports like basketball or jogging can trigger the condition but often it is accompanied by overweight in the individual.   According to growth consultants, the rapid graying of Europe's population with related increases in the incidence of musculoskeletal problems (particularly osteoarthritis) is expected to be a key driver for orthopaedic prosthetic implant devices over the long term. At the same time, enhanced clinical outcomes and clinical efficacy are boosting the number of procedures carried out on patients in younger age groups ().             Experts believe the total knee replacement could dramatically cut the recovery time of patients, freeing up hospital beds more quickly and saving money (2003). The operation uses a minimally invasive technique to insert knee implants through an incision half the size of the usual ten to 13 inch wound. This results in much less cutting of the thigh muscles, leading to less pain and faster recovery.             A well-executed total knee replacement can last up to 15 years (95% predicted survival of the implant). Still, the operation and recovery can be grueling. Traditionally, surgeons make a 12-inch incision in the front of the knee, peel back the kneecap, and cut through the quadriceps muscle and a tendon that attaches it. That allows open access to the thigh and shin bones, which are cut to fit the metal-and-plastic joint implant (2004).    Like any surgery, knee joint replacement carries certain life-threatening risks, such as infection, blood clots and complications from anesthesia. Other complications include nerve damage, dislocation of breakage after surgery, and wearing out or loosening of the joint over time ( 2004). After the operation, there can be wound infection and worse, infection of the knee replacement. These may require prolonged antibiotics and possible removal of the implants.             Perioperative complications as defined by the investigator occurred in 5.4 percent of patients and 7.6 percent of knees. Most of these complications were "knee related" or deep venous thrombosis. There were only eight cardiovascular or pulmonary complications reported among nearly 6,000 patients, suggesting that these adverse effects were not fully addressed in the literature (2004).   Post-Operative Care               After the knee replacement surgery, it is expected that the care of the client can become complex as a result of physiological changes that may occur. Another thing is that, the client now has an artificial knee in him and this is something that the client has to get used to.               To assess the client’s condition after the knee replacement surgery, the nurse should apply critical thinking while relying on information from the preoperative nursing assessment, knowledge regarding the surgical procedure performed, and the events that occurred after surgery ( 2004).               The information that the nurse gathered from the client will help the nurse to detect any change and make decisions about client’s care. A variation from the client’s normal signs may indicate the onset of surgically related complications (Potter & Perry, 2004).               The nurse should thoroughly document the assessment, including vital signs, level of consciousness, comfort level, pain, range of motion or mobility among other things. The initial findings are a baseline for comparing changes before and after the surgery.               The nurse also has the responsibility of explaining to the client and his/her family the purpose of post-operative procedures or equipment and the status of the client.   Assessment and Nursing Diagnosis               Two acute needs of the client after total knee replacement surgery are pain and mobility. The physiology of these two are altered after surgery and the nurse needs to be extra attentive to these needs.             The pain after undergoing knee replacement surgery is intense but is still somewhat manageable (2003). In the pain treatment of the patient, the nurse has to first and foremost assess resources for pain management. After this, the healthcare team looking after the patient should develop a collaborative plan.             In assessing the client’s pain, his or her self-report of the pain is the single most reliable indicator of the existence and intensity of the pain experienced and any related discomfort (2004). It is also important to take note that if the client senses that the nurse doubts that the client felt pain, there is a possibility that the client will share little information about their pain. Therefore the nurse should see to it that the client will feel comfortable in discussing whatever he or she feels.             It is imperative that the nurse set the stage for the relationship that allows for open communication about pain. Simple measures such as sitting when talking to clients about pain lets clients know that the nurse has the time and the interest to assess the pain felt by the client ( 2004).             The kind of pain that the client experiences after surgery is acute pain which everyone experiences some level of during one’s lifetime. It is actually protective and has an identifiable cause, in this case, the surgery itself was the cause of the pain. This kind of pain has limited tissue damage and emotional response.                         Acute knee pain usually follows injury or surgery. Chronic knee pain on the other hand can be related to disease such as osteoarthritis or associated with overuse or untreated injuries to muscles, ligaments, or tendons.   Since acute pain is expected to be healed and the cause can be identified, healthcare teams are usually willing to treat the acute pain experienced by the client. Nurses should be aware that unrelieved acute pain can progress to chronic pain (2004).                                                                        Assessment of the client’s mobility enables the nurse to determine the client’s coordination and balance while walking, bending, and doing usual movements with the knee. The assessment of mobility has three components: range of motion, gait, and exercise ( 2004).             Assessing the range of motion is used to determine the degree of damage or injury to the joint or it could be from recovery. The nurse should ask questions about joint stiffness, swelling, pain, limited movement, and unequal movement. Assessing the client’s gait or the manner and style in walking allows the healthcare professional like the nurse to draw conclusions about balance and posture ( 2004).             Other than that, malignant hypothermia could occur and is a potentially lethal condition that can occur in clients who underwent knee replacement surgery and received general anesthesia. This should be suspected when there is unexpected tachycardia and tachypnea, jaw muscle rigidity, body rigidity of limbs, abdomen and chest, or hyperkalemia (2004).               Clients who have temperature elevations should be assessed and nursing interventions should be planned for a possible infectious process. Postoperative interventions of deep breathing and coughing, early ambulation, and aseptic care of the surgical wound of the knees will decrease the client’s risk of postoperative infections.               Temperature regulation is important after surgery. Clients are often cool after the procedure and should be provided with warmed blankets. It is also important to note that when the client is shivering, it may not be a sign of hypothermia            but rather a side effect of certain anesthetic agents. Meperidine (Demerol) may be given in small increments to decrease shivering as prescribed by the physician ( 2004).   Implementation               The client may be recommended to rest, the use of knee supports, the use of walking aids such as canes and walkers. Physical therapy and appropriate exercises may also be suggested. Occasionally, steroid injections into the knee may decrease pain and inflammation. A variety of drugs for arthritis exists. These range from painkillers aspirin and acetaminophen to NSAIDs (nonsteroidal anti-inflammatory drugs) such as diclofenac, meloxicam, piroxicam, mefenamic acid, ibuprofen, to the latest COX-2 inhibitors (rofecoxib and celecoxib).               Patients whose pain level is reported as tolerable should to be more active and willing to engage in physical therapy. With emphasis being placed on providing quality care while striving for cost-effectiveness, such adverse outcomes need to be targeted for prevention from all possible angles ( 1999).   Summarization and Conclusion             Knee replacement surgery is a safe and cost-effective treatment for persistent knee pain and disability, and increasing numbers of patients are seeking it at an earlier age in order to minimize or eliminate pain and difficulty in moving the knee joint.               Total knee replacement is "highly successful in relieving pain and restoring joint function. In a standard total knee replacement, the damaged areas of the thighbone, shinbone and kneecap are removed and replaced with prostheses. The ends of the remaining bones are smoothed and reshaped to accommodate the prostheses.                         Although knee replacement surgeries are effective in treating osteoarthritis and other knee injuries, there are also post-operative complications which have to be taken cared of by the healthcare team. There are also needs that need to be taken cared of. These are the acute needs for the management of pain and mobility after surgery.               After surgery, the nurse still has many important factors to assess in order to make sure that the client is doing well after the surgery. The nurse should continue assessing the client until the critical factors are on a less intensive basis and the client can then be discharged.

TOTAL KNEE REPLACEMENT SURGERY

TOTAL KNEE REPLACEMENT SURGERY Introduction People undergo total knee replacement when arthritis or injury ...