Knee Replacement

Knee Replacement

Knee Replacement
Painful knees are a common problem - often the result of wear-and-tear from sports injuries or obesity, which leads to a degenerative form of arthritis called osteoarthritis. Pain relievers and other treatments can help. When knee damage is severe, a total knee replacement can relieve the pain and allow you to be more active again. Learn more about knee replacement surgery from out experts.

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  • 1 Answer
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    A Orthopedic Surgery, answered on behalf of
    Many elderly people have other complicating medical conditions that must be understood and, if possible, improved prior to joint replacement surgery and then managed postoperatively. This often requires the person's doctor or a specialist working as part of the team.

    A great hospital with a proven track record, which provides designated teams specializing in the care of people with hip and knee replacement, also is a must. Because elderly people often have other serious conditions and/or significant past medical histories, caring for them in a hospital with full medical services, including intensive care units (ICUs) and 24-hour-a-day, in-house intensivist care, is extremely important.

    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.
  • 1 Answer
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    A Orthopedic Surgery, answered on behalf of
    If a total knee replacement (TKR) has failed, a review of the surgeon’s operative report is important. This report could give clues regarding specific difficulties or peculiarities that were encountered during the operation.

    The surgeon also needs to review the “implant record.” Like the operative report, the implant record is also a permanent part of the medical record and contains labels provided by the manufacturer naming the company that manufactured the implant, the implant brand name, size, U.S. Food and Drug Administration (FDA) number and expiration date.

    This information becomes critical if more surgery is being considered, and also might give a clue as to why the knee is not performing satisfactorily. Particular brands or types of implants may have known problems and a poorer track record than others.

    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.
  • 1 Answer
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    A Orthopedic Surgery, answered on behalf of
    For a failed total knee replacement (TKR), the surgeon might suggest aspirating the knee to look for evidence of infection. Joint infection is often a difficult diagnosis to make.

    A test has become available called the Synovasur test. Synovial fluid is aspirated and sent to a special laboratory where specific tests are performed. These include measuring a biomarker called alpha defensins. Biomarkers are proteins that act as the body’s natural antibiotics and are present when the body is fighting infection but not present in other conditions that can mimic infection.

    The Synovasure test has greatly improved doctors' ability to diagnose infection, as it helps differentiate inflammation and other causes of knee pain from infection.

    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.
  • 1 Answer
    A
    A Orthopedic Surgery, answered on behalf of
    If a total knee replacement (TKR) has failed, good quality x-rays are important. These include an x-ray taken with you standing (which physiologically loads to the joint) and occasionally also a full-length x-ray that includes the hip and ankle.

    These x-ray images give important information regarding component alignment, sizing and if the joint appears stable or loose. X-rays also reveal what type of method was used to fix the components to the bone. The types of information revealed by x-ray images include the following:
    • Were the components cemented or press-fit with the hope that stability would be achieved with bone ingrowth?
    • Do the interfaces where the bone contacts either the cement or prosthesis appear acceptable or is there a suggestion of loosening or osteolysis (bone destruction)? Accessing the equality of the inside and outside prosthetic joint space might give clues regarding soft tissue balance.
    • Does the patella appear to be tracking centrally or is it pulled to one side?
    • Are there residual bone spurs, which could be causing irritation or inhibit motion?
    A review of the x-rays that were taken prior to TKR also gives clues regarding the knee’s preoperative deformity, appearance and underlying anatomy.

    At this point, many times the surgeon will have a pretty good idea of what is causing the problem. Further x-rays might be necessary as well as other studies such as blood work, including an erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP).

    Occasionally, the surgeon will request a bone scan, radioactive white blood cells (WBC) labeled scan, or metal artifact reduction sequences (MARS) magnetic resonance imaging (MRI). In special circumstances computed tomography (CT) is ordered to help better understand component positioning.

    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.
  • 1 Answer
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    A Orthopedic Surgery, answered on behalf of
    It is essential that your doctor examine your knee after a failed total knee replacement (TKR). Your doctor will want to answer a number of questions during the physical exam:
    • Is knee alignment acceptable?
    • Did the incision heal satisfactorily?
    • Does the skin overlying the knee appear red and hot?
    • Is the knee tender? If so, where?
    • Is there any drainage?
    • Does the knee appear swollen?
    • Is there an effusion (fluid in the joint)?
    • Does the knee fully extend?
    • Can you actively maintain that extended position?
    • How much does it flex?
    • Is this range of motion associated with pain or is it painful only in a particular position?
    • Is the kneecap tracking or does it slide off to the side during flexion?
    • When stressing the knee, is there more laxity on one side compared to the other?
    It is important to test for stability with the knee in extension and various degrees of flexion. The anterior/posterior (front/back) stability also needs to be established. Other conditions that can cause knee pain must also be considered and ruled out, such as spinal disease and hip disease with referred pain to the knee.

    This is just a sampling of information that the physical exam can provide, giving clues as to why the result is not acceptable and to help determine the next steps to correct the problem or problems.

    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.
  • 1 Answer
    A
    A Orthopedic Surgery, answered on behalf of
    If you're not happy with your total knee replacement (TKR), a surgeon will begin with a careful history that will include many questions. Be prepared to discuss with him or her the answers to the following:
    • Why are you not happy with your TKR?
    • How disabling was your condition before surgery? Were you barely able to get up from a seated position and walk or did you have just a little discomfort after 54 holes of golf, for example?
    • Were there any problems with the incision after surgery or any need for further surgery (which might increase the suspicion of an underlying infection)? Were antibiotics extended after surgery or initiated after discharge? Many infections are subtle and difficult to diagnose.
    • What is the main complaint? Pain, stiffness, poor range of motion or feeling like the knee is not stable and that you can’t trust the new knee? Some people have subtler complaints, such as the new knee simply is not comfortable or doesn’t feel natural.
    • If you're experiencing pain, is the pain only with activity such as walking, or is it present all the time, even at rest? Does the discomfort awaken you from sleep? Can you do something that improves or relieves the pain such as assuming a particular position with the leg, using ice or taking medication for pain?
    • Was there ever a period when you seemed to be doing well or at least improving, and then the circumstances changed? Are your symptoms now slowly improving, stable or worsening? Are the complaints tolerable or are they bad enough that you want more tests, hoping to learn the specific etiology and would even consider more surgery if the condition could potentially be improved?
    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.
  • 1 Answer
    A
    A Orthopedic Surgery, answered on behalf of
    Defining success for total knee replacement (TKR) surgery begins prior to surgery, during a frank discussion between you and your surgeon. The conversation should include what your goals are and if the surgeon thinks those goals are achievable and appropriate. Some goals simply are not reasonable, such as long-distance running or team soccer, particularly if the new joint is to enjoy longevity.

    Unfortunately, there are a significant number of people who have undergone TKR and are not happy with the result. Some studies estimate 20% or more fall into this category. Defining success or a satisfactory result can mean two very different things to an individual who had the total knee versus the surgeon who implanted it. At the end of the day, it’s most important that the person who had the TKR is happy.

    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.
  • 1 Answer
    A
    A Orthopedic Surgery, answered on behalf of
    The goals of total knee replacements (TKR) are to help assure a stable, pain-free knee with which the patient is happy. These goals include the following:
    • Recreating limb alignment and a neutral mechanical axis so that weight-bearing forces are nearly equalized between the inner and outer compartments of the knee. This also has the effect of straightening any pre-TKR bowlegged or knock-kneed angulation.
    • Balancing the soft tissue sleeve that surrounds the knee so that as the knee moves from extension to flexion, equal and physiologic tensions or pressures are experienced in the medial and lateral ligaments.
    • Creating normal knee movement (kinematics) as the knee ranges from extension into flexion and then back to extension. Normally, as the knee flexes, the tibia internally rotates and the femur pivots on the inner or medial compartment. During extension, this normal rotation or pivot reverses and the tibia externally rotates. The cruciate ligaments as well as other soft tissues and the shape of the bones help to control this normal complex movement.
    The components implanted during TKR do a wonderful job of re-surfacing the end of the bones that make up the knee and this prevents the bones from rubbing. Bone-on-bone pain is one of the main reasons why arthritic knees are painful and a major trigger for people deciding it’s time to choose knee replacement. For the result to be optimal after TKR, these three conditions need to be met. This can prove very difficult to accomplish consistently, especially with some people’s particular deformities or underlying conditions.

    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.
  • 1 Answer
    A
    A Orthopedic Surgery, answered on behalf of
    Some patients develop a hypersensitivity to one or more of the heavy metals used in total knee replacement surgery and develop symptoms. Most total knee prostheses used in total knee replacements are made with cobalt and chromium. Nickel might also be a constituent metal.

    Symptoms can manifest themselves locally (in the knee) or systemically (throughout the body). Unfortunately, preoperative skin and serum (blood) testing for heavy metals has not translated into a strong and reliable predictor for these hypersensitivities and reactions.

    Historically, an individual with multiple allergies and/or the inability to wear costume jewelry may be susceptible. This relationship is not absolute.

    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.
  • 1 Answer
    A
    A Orthopedic Surgery, answered on behalf of
    A proper workup for a painful total knee replacement (TKR) focuses on three critical conditions that must be combined to recreate a stable, pain-free TKR with a good result. The mechanical axis must be restored, the soft tissues must be balanced throughout the range of motion and normal knee kinematics recreated. However, it is very difficult to accomplish these conditions consistently, particularly with some pathology and deformities.

    Orthopedic surgeons address these goals by using two different computer systems, which have vastly improved the consistency and results people achieve after TKR. These computers provide data and measurements that are more accurate and reproducible, as well as improve decision-making during surgery. By using these computer systems, surgeons are much more aware of how subtle changes in implant position, boney resection and the loading pressures experienced by the surrounding ligamentous sleeve vastly affect the knee’s final balance and kinematics. This greatly enhances the final result.

    Typically, surgeons attempt to optimally rotate the tibial component to match the femoral component by the “looking and feeling” method of sizing up the anatomic features or landmarks on the bone. Many times, the precise location of these landmarks is difficult to define or feel, especially in a deformed and arthritic knee, and this leads to a less-than-desired accuracy. Patella tracking also is majorly affected by femoral rotation.

    DISCLAIMER: Trinity Health recognizes that people seek medical information on a variety of topics for a variety of reasons. Trinity Health does not condone or support all practices covered in this site. As a Catholic health care organization, Trinity Health acts in accordance with the Catholic tradition.

    Please note, the information contained on this website is provided to supplement the care provided by your physician. It is not intended to be a substitute for professional medical advice. Always seek the advice of a qualified health care provider if you have questions regarding your medical condition or before starting any new treatment. In the event of a medical emergency always call 911 or proceed to your nearest emergency care facility.