Total Knee Replacement

by Dr. Scott Stanislaw

Joint replacement has been one of the most beneficial and significant orthopedic technologies developed over the past few decades. Since being first performed in the late 1960’s, advances in knee replacement technology have been tremendous. These advancements have been instrumental in alleviating pain, restoring function, and correcting deformity. To those who need joint replacement, an artificial joint can greatly improve the quality of life. More than 500,000 Americans undergo knee replacement each year in the United States. The recipients of these knee replacements experience great improvements in pain relief, activity, and function.

The knee, the largest joint in the body, is essential to many everyday activities such as walking, climbing stairs, and getting into a car. The knee is composed of many complex interacting structures. The bones of the knee interact to form a joint that acts like a hinge. The lower end of the thigh bone, called the femur, rotates upon the upper end of the shin, called the tibia. The kneecap, called the patella, slides in a groove on the front of the thighbone. The joint surfaces of these bones are covered with articular cartilage. Soft tissue structures such as cruciate ligaments and meniscus cartilage are also key in the normal function of the knee. The synovial lining provides the lubrication for the joint to allow smooth and nearly frictionless motion. Injury or arthritis can disrupt the knee joint and result in pain, swelling, and dysfunction.

There are many causes of chronic knee pain and dysfunction, the most prevalent of which is arthritis. There are many forms of arthritis including osteoarthritis, rheumatoid arthritis, and traumatic arthritis. Osteoarthritis, usually affecting people over 50 years of age, is the most common form of arthritis. Rheumatoid arthritis, the result of an autoimmune condition that creates joint destruction, is the second most common form. Traumatic arthritis, often following a serious injury such as a fracture or an untreated ligament injury, is another common form of arthritis. Using examination, x-rays and blood tests, a physician can evaluate the type of arthritis and determine the extent of deterioration.

The form of arthritis, the degree of deterioration, and the extent of symptoms are considered in forming a treatment plan. Many nonsurgical treatments exist but when these treatments fail, joint replacement should be considered. The decision to undergo total knee replacement surgery should be a cooperative decision made by the patient, the physician, and family members. The decision making process should include a discussion about alternative surgical treatments such as arthroscopy, cartilage transplantation, unicompartmental knee replacement, and minimally invasive knee replacement. An orthopedic surgeon can review total knee replacement and alternative surgical treatments that may also be of benefit.

The orthopedic evaluation has many components. The general health and medical history is evaluated to assess pre-qualification for joint replacement surgery. Physical examination is completed to assess knee motion, stability, and strength. Xray studies are necessary to determine the extent of deterioration and the degree of knee deformity. Additional testing, such as blood tests, MRI scanning, and bone scanning may be needed to assess other factors important for the procedure. The orthopedic surgeon can review the results and discuss the best surgical method to relieve pain and restore function.

Once a decision to proceed with total knee replacement has been made, the surgeon will explain the necessary preparations prior to surgery. The orthopedic surgeon may request a preoperative medical evaluation by a family physician or cardiologist in order to identify any conditions that could interfere with joint replacement surgery. Additionally, preoperative testing including chest x-ray, EKG, and blood tests may be necessary to aid in the planning for surgery. Prior to surgery, the orthopedic surgeon will review the patient’s current medication list and give instructions as to which medications should be stopped before surgery.

There are many other considerations to evaluate before joint replacement. Strong consideration should be given to having all necessary dental and periodontal work completed before joint replacement surgery. Also, anyone having chronic urinary symptoms or infections should consider undergoing urologic treatment prior to knee replacement. In addition, a case manager or social worker can help to evaluate and make advanced arrangements for any at home postoperative needs. Equipment needs such as a walker, elevated seat, and shower chair can be assessed. Additional needs or considerations may be discussed with the orthopedic surgeon.

Once planning and arrangements have been completed, the knee replacement process may start. Admission to the hospital is usually done on the day of surgery. After admission, the anesthesia team meets with the patient and family to discuss anesthesia options. The most common forms of anesthesia are general, spinal, and epidural anesthesia. Under general anesthesia the patient is asleep throughout the procedure. When undergoing spinal or epidural anesthesia, the patient is awake or sedate and the legs are numb or anesthetized.

Total knee replacement surgery takes approximately 60-90 minutes to be completed. During the surgery, the orthopedic surgeon removes the deteriorated cartilage, bone spurs, and thin sections of arthritic bone. The severely worn articular cartilage is replaced with metal joint replacement components. A special spacer, made of a polyethylene type plastic, is inserted between the metal replacement parts and provides a low friction surface. The kneecap is also resurfaced with a specialized plastic component. The numerous different designs and available sizes of knee replacement parts allow the orthopedic surgeon to choose the most appropriate type for each unique patient.

After the procedure is completed, the patient usually remains in the recovery room for one to two hours prior to being transported to a hospital room. The length of the hospital stay is usually two to three days. Depending on postoperative needs and mobility, various forms of physical therapy and rehabilitation are initiated and utilized. In the event that additional rehabilitation time is needed prior to going home, other extended stay options are available.

Most patients opt for a home recovery program, which is reviewed prior to surgery and again during the hospital stay. Exercise and physical therapy is essential for successful and functional knee replacement. A patient who follows this program and gives full effort can expect to be able to return to normal household activities within three to six weeks. Driving can typically be resumed in four to six weeks if the appropriate criteria are fulfilled. Once fully recovered, activities such as swimming, golfing, light hiking, biking and dancing can be enjoyed. Activities such as running, jumping, and high impact sports should be avoided as these activities can have detrimental effects on the joint replacement. Taking proper activity precautions and maintaining good health should lead to a joint replacement that lasts ten to twenty years.

Dr. Scott Stanislaw is an orthopedic surgeon with Fondren Orthopedic Group LLP. Dr. Stanislaw practices in the Kingwood, Atascocita and Fall Creek locations. He graduated from Albright College in Reading, Pennsylvania, where he received a degree in biochemistry. He received his medical degree from the Medical College of Pennsylvania in Philadelphia, and was elected to the Alpha Omega Alpha medical honor society. Dr. Stanislaw went on to complete his internship and residency in orthopedic surgery at Geisinger Medical Center, a Level 1 Trauma Center in Danville, Pennsylvania. He also completed training in pediatric orthopedics at A I duPont Institute in Wilmington, Delaware. He is board certified by the American Board of Orthopedic Surgeons.