BIRMINGHAM HIP* Resurfacing System
An exciting new alternative to total hip replacement is now available in the United States. Used successfully for years around the globe, the BIRMINGHAM HIP Resurfacing System has recently been approved by the Food and Drug Administration for use in the United States. Now, patients suffering from hip pain due to arthritis, dysplasia or avascular necrosis can benefit from its conservative approach to treatment.
Because this technologically advanced surgical procedure resurfaces rather than replaces the end of your femur (thighbone), you may participate in more strenuous physical activity with an implant that is potentially more stable and longer-lasting than traditional total hip replacements. And if future revision surgery is required, it may be a less complex and less traumatic procedure.
In fact, a 1,626-hip study of the effectiveness of the technique found that 99.5-percent of patients responded they were “Pleased” or “Extremely pleased” with the results of their BIRMINGHAM HIP Resurfacing surgery.
Hip resurfacing is intended for young, active adults who are under 60 years of age and in need of a hip replacement. Adults over 60 who are living non-sedentary lifestyles may also be considered for this procedure. However, this can only be further determined by a review of your bone quality.
There are certain causes of hip arthritis that result in extreme deformity of either the head of the femur or the acetabulum (hip socket). These cases are usually not candidates for hip resurfacing.
Talk with your orthopaedic surgeon to determine if hip resurfacing is the right option for you.
There are four primary diseases of the hip that may indicate the need for BIRMINGHAM HIP Resurfacing.
Osteoarthritis of the hip is a disease which wears away the cartilage between the femoral head and the acetabulum, eventually causing the two bones to scrape against each other, raw bone on raw bone. When this happens, the joint becomes pitted, eroded and uneven. The result is pain, stiffness and instability, and in some cases, motion of the leg may be greatly restricted.
Patients with osteoarthritis often develop large bone spurs, or osteophytes, around the joint, further limiting motion.
Osteoarthritis is a common, degenerative disease, and although it most often occurs in patients over the age of 50, it can occur at any age, especially if the joint is in some way damaged.Causes
Osteoarthritis of the hip is a condition commonly referred to as “wear and tear” arthritis. Although the degenerative process may accelerate in persons with a previous hip injury, many cases of osteoarthritis occur when the hip simply wears out. Some experts believe there may exist a genetic predisposition in people who develop osteoarthritis of the hip. Abnormalities of the hip due to previous fractures or childhood disorders may also lead to a degenerative hip. Osteoarthritis of the hip is the most common cause for both total hip replacement and hip resurfacing.Symptoms
The first and most common symptom of osteoarthritis is pain in the hip or groin area during weight bearing activities such as walking. People with hip pain usually compensate by limping, or reducing the force on the arthritic hip. As a result of the cartilage degeneration, the hip loses its flexibility and strength, and may lead to the formation of bone spurs. Finally, as the condition worsens, the pain may be present all the time, even during non weight-bearing activities.Rheumatoid Arthritis
Unlike osteoarthritis, which is a “wear and tear” phenomenon, rheumatoid arthritis is a chronic inflammatory disease that results in joint pain, stiffness and swelling. The disease process leads to severe, and at times rapid, deterioration of multiple joints, resulting in severe pain and loss of function.Causes
Although the exact cause of rheumatoid arthritis is unknown, some experts believe that a virus or bacteria may trigger the disease in people having a genetic predisposition to rheumatoid arthritis. Many doctors think rheumatoid arthritis is an autoimmune disease in which the synovial tissue of the joint is attacked by one’s own immune system. The onset of rheumatoid arthritis occurs most frequently in middle age and is more common among women.Symptoms
The primary symptoms of rheumatoid arthritis are similar to osteoarthritis and include pain, swelling and the loss of motion. In addition, other symptoms may include loss of appetite, fever, energy loss, anemia, and rheumatoid nodules (lumps of tissue under the skin). People suffering with rheumatoid arthritis commonly have periods of exacerbation or “flare ups” where multiple joints may be painful and stiff.Developmental Dysplasia of the Hip
Developmental dysplasia of the hip (DDH), also called hip dysplasia, is a lifelong condition, shared by one in 1,000 people. Because DDH patients are born with an altered hip anatomy, the joint doesn’t develop the normal wear patterns over the years. This leads to “wear and tear” arthritis at a relatively early age.Causes
The most significant risk factor for DDH is a family history of the disorder. Women have a higher rate of DDH, as do first-born children and babies delivered breech.Diagnosis
Developmental dysplasia of the hip often can be diagnosed in the first year of life.
Symptoms include diminished leg movement in the affected hip, shortening of the leg on the affected side, or asymmetry in leg positions. One or both hips may have DDH.Avascular Necrosis
Avascular necrosis (AVN) of the hip results when poor blood circulation starves the bones that form the hip joint. In time, the starved bone dies, and the hip joint collapses.
AVN, sometimes called hip osteonecrosis, is most prevalent in younger or middle-aged adults.Causes
Alcoholism and corticosteroids are by far the leading causes of AVN. In rarer cases, AVN can result from a blockage in blood vessels from sickle cell anemia or fat particles, or from dislocation of the hip due to trauma.Symptoms
Hip pain, especially after standing or walking, is the most common symptom. Hip AVN most commonly afflicts the femoral head, where the femur (or thighbone) attaches to the pelvis (or hip bone). The femoral head may weaken and collapse.
Before deciding on hip resurfacing, your physician may try several non-surgical, conservative measures to relieve the pain and inflammation in your hip.Lifestyle Modification
The first alternative to hip replacement involves such lifestyle modification measures as weight loss, avoiding activities involving long periods of standing or walking, and the use of a cane to decrease the stress on the painful hip.Exercise and Physical Therapy
Exercise and physical therapy may be prescribed to improve the strength and flexibility of your hip and other lower extremity muscles. Your exercise program may include riding a stationary bike, light weight training and flexibility exercises. An aquatic therapy program is especially effective for the treatment of arthritis since it allows mild resistance while removing weight bearing stresses. For an appropriate exercise program, contact an experienced physical therapist.Anti-inflammatory Medications
Arthritis pain is primarily caused by inflammation in the hip joint. Reducing the inflammation of the tissue in the hip can provide temporary relief from pain and may delay surgery.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) may be prescribed to decrease the inflammation associated with arthritis. A new classification of NSAIDs, called Cox-2 inhibitors, are often very effective in decreasing pain.
In a small number of cases, the doctor may prescribe corticosteroids, such as prednisone or cortisone, if NSAIDs are not effective. However, due to the higher rate of side effects associated with corticosteriods, a physician must closely monitor their use.Glucosamine/Chondroitin
Two dietary supplements, Glucosamine and Chondroitin (commonly available in a combined tablet), may decrease the symptoms of hip arthritis. Glucosamine and Chondroitin sulfate are both naturally occurring molecules, and issues associated with both remain under active research. However, it appears that many people taking these nutrition supplements on a regular basis note a decrease in their arthritis symptoms.
There exist a number of non-surgical alternatives to total hip replacement surgery. Such measures as lifestyle modification, exercise and physical therapy, and medication should be implemented before deciding on surgery. If all of these measures have been exhausted and your orthopedist recommends surgical intervention, BIRMINGHAM HIP Resurfacing can be very successful in decreasing pain and greatly improving function.
Until just recently, your orthopedist would likely be recommending total hip replacement surgery at this point of your disease state. While it is clearly a more bone-sacrificing procedure than hip resurfacing, total hip replacement is a safe and effective surgery, and is performed more than 300,000 times per year in the United States.
As you may know, total hip replacement requires the removal of the femoral head and the insertion of a hip stem down the shaft of the femur. Hip resurfacing, on the other hand, preserves the femoral head and the femoral neck. During the procedure, your surgeon will only remove a few centimeters of bone around the femoral head, shaping it to fit tightly inside the BIRMINGHAM HIP Resurfacing implant.
Your surgeon will also prepare the acetabulum for the metal cup that will form the socket portion of the ball-and-socket joint. While the resurfacing component slides over the top of the femoral head like a tooth cap, the acetabular component is pressed into place much like a total hip replacement component would be.
BIRMINGHAM Hip Resurfacing System
Total Hip Replacement
The BIRMINGHAM HIP Resurfacing implant is not brand new. It has been in use around the world since 1997 and has since been implanted more than 60,000 times. It is new to the United States, however, where it was approved for use by the Food and Drug Administration in May 2006.
Although hip resurfacing is not a new concept, the technology behind the ground-breaking BIRMINGHAM HIP was developed by British orthopedic surgeons Mr. Derek McMinn and Mr. Ronan Treacy. The two surgeons now train orthopedists from around the globe on behalf of London-based medical device manufacturer Smith & Nephew. US surgeons given access to this implant may travel to England for specialized training or may train at one of the few US centers capable of hosting these focused sessions.Patient Benefits
The benefits to patients of the BIRMINGHAM HIP Resurfacing technique and implant are clear. The implant’s head size, its bearing surfaces, and its bone-sparing technique make it a preferred choice for young, active patients. While the implant’s rate of survivorship is comparable to standard total hip replacements after five years, these three key advantages set the resurfacing technique and implant apart from its total hip replacement counterparts.
The most noticeable aspect of this implant is its size. While it closely matches the size of your natural femoral head, it is substantially larger than the femoral head of a total hip replacement. This increased size translates to greater stability in your new joint, and it decreases the chance of dislocation of your implant after surgery.
Dislocation is a leading cause of implant failure in total hip replacement. While total hip implants dislocate at a rate of one to three-percent over the lifetime of the implant, a study of 2,385 BIRMINGHAM HIP Resurfacing patients found that dislocation occurred in only 0.3-percent of cases five years after surgery.Healthy Hip > BHR Implant > Total Hip
BIRMINGHAM HIP Resurfacing takes advantage of one of the orthopaedic medical industry’s most technologically advanced bearing surfaces. That means that the surfaces of the ball and the socket are made from materials that dramatically reduce joint wear when compared to traditional hip implant materials.
In this case, both the ball and socket are made from tough, smooth cobalt chrome metal. Traditionally, only the ball is made from cobalt chrome, and the socket is lined with a plastic cup. While this plastic cup has some design advantages, it does wear out over the course of many years since it rubs against the metal ball at a rate of nearly two million footsteps per year in physically active adults.
The plastic particles released into the area around the joint as a result of this plastic wear can lead to a condition called osteolysis, which causes the bone around the implant to soften, become unstable, and ultimately a corrective surgery and new implant are required.
However, when both surfaces of a hip implant are made from cobalt chrome, wear particles are reduced by 97-percent1, thus potentially extending the life of the implant.
There may be risks associated with metal-on-metal hip implants, though. While no evidence has been established on the subject, some are concerned that the increased level of metal ions found in the blood of metal-on-metal hip recipients may have negative effects on the human body. For this reason, some surgeons may not implant such a device in a patient with kidney disease (since healthy kidneys filter ions from your body) or in women who are or may become pregnant.Bone Conservation
Perhaps the greatest benefit of the BIRMINGHAM HIP Resurfacing implant is the fact that it conserves substantially more bone than a total hip replacement. This is important for two key reasons.
First, unlike a total hip replacement, the BIRMINGHAM HIP Resurfacing preserves your natural femoral neck. It is this neck length and angle that determines the natural length of your leg, and since it is not removed and replaced with an artificial device during a resurfacing procedure, concerns regarding leg length discrepancy are virtually non-existent.
Second, if your surgeon should determine you need to have your BIRMINGHAM HIP implant replaced at some point in the future, you may undergo a regular total hip replacement surgery. If you had originally undergone total hip replacement instead of hip resurfacing, you would be dealing with a more traumatic and complex procedure and you would be receiving a more invasive implant.BHR Cuts > Total Hip Cuts
Once you and your orthopedic surgeon decide that hip resurfacing is right for you, the days and weeks leading up to surgery, as well as the day of surgery, require preparation. The following is a description of what you may expect.Pre-operative Procedure
You and your orthopedic surgeon may participate in an initial surgical consultation. This appointment may include pre-operative X-rays, a complete medical and surgical history, physical examination, and a comprehensive list of medications and allergies. During this visit, your orthopedic surgeon will likely review the procedure and answer any questions.
Your orthopedic surgeon may require that you have a complete physical examination by your internist or family physician, as you will need to be cleared medically before undergoing this procedure. Your surgeon may suggest that you consider donating your own blood to save in case you require it during surgery or in the event of a post-operative blood transfusion.Preparation for the Hospital You may want to bring the following items to the hospital:
- Clothing underwear, socks, t-shirts, exercise shorts for rehabilitation
- Footwear walking or tennis shoes for rehab, slippers for hospital room
- Walking aids walker, cane, wheelchair, or crutches if used prior to surgery
- Insurance information
- You should follow your regular diet on the day before your surgery.
- DO NOT EAT OR DRINK AFTER MIDNIGHT the night before surgery. On the morning of surgery, you may brush your teeth and rinse your mouth, but do not swallow any water.
- Follow your doctor's instructions regarding use of medication in the days leading to surgery. In some cases, a blood thinner may be ordered a few days before surgery. Generally, aspirin and non-steroidal anti-inflammatory medications should not be taken seven days prior to surgery.
- Try to get long, restful nights of sleep. A sleeping medication may be ordered the evening before surgery.
On the morning of surgery, once you are admitted to the hospital, you will be taken to the appropriate pre-surgical area where the nursing staff will take your vital signs, start intravenous (IV) fluids, and administer medications as needed. You will be asked to empty your bladder just prior to surgery, and to remove all jewelry, contacts, etc. (Rings not removed will be taped.) Once you change into a hospital gown, you will be placed on a stretcher, and transported to the operating room. The anesthesiologist will meet you and review the medications and procedures to be used during surgery.Surgery and Recovery
When surgery is completed, you will be taken to the recovery room for a period of close observation. Your blood pressure, heart rate, respiration, and body temperature will be closely monitored by the recovery room staff. Special attention will be given to your circulation and sensation in your feet and legs. When you awaken and your condition is stabilized, you will be transferred to your room.Although the protocols may vary from hospital to hospital, you may awaken to some or all of the following:
- A large dressing may have been applied to the surgical area.
- You may see a hemovac suction container with tubes leading directly into the surgical area. This device allows the nurses to measure and record the amount of drainage from the wound following surgery.
- An IV will continue post-operatively in order to provide adequate fluids. The IV may also be used for administration of antibiotics or other medications.
- A catheter may have been inserted into your bladder as the side effects of medication often make it difficult to urinate.
- An elastic hose may be applied to decrease the risk of deep vein thrombosis (DVT). A compression device may also be applied to your feet to further prevent DVT.
- A patient-controlled analgesia (PCA) device may be connected to your IV, allowing you to control the relative amount and frequency of pain medication. To prevent overdose, the unit is programmed to deliver a pre-defined amount of pain medication anytime you press the button of the machine.
One of the critical success factors for a positive outcome is following the physical rehabilitation process. In order to help achieve the goals for a successful hip resurfacing procedure, you must actively participate in the rehab process and work diligently on your own, as well as with the physical therapists, to achieve optimal results.Early Rehabilitation
Your recovery program usually begins the day after surgery. The rehabilitation team will work together to provide the care and encouragement needed during the first few days after surgery.
You may be given a device called an incentive spirometer that you inhale and exhale into. It measures your lung capacity and assists you in taking deep breaths. These exercises reduce the collection of fluid in the lungs after surgery, preventing the risk of pneumonia. Coughing is an effective tool for loosening any congestion that may build in the lungs following surgery.
The physical therapist will begin as early as 1-2 days after surgery. They will teach you some simple exercises to be done in bed that will strengthen the muscles in the hip and lower extremity. These exercises may include:
- Gluteal Sets Tighten and relax the buttock muscles
- Quadricep Sets Tighten and relax the thigh muscles
- Ankle Pumps Flex and extend the ankles
Your physical therapist will also teach you proper techniques to perform such simple tasks as:
- Moving up and down in bed
- Going from lying to sitting
- Going from sitting to standing
- Going from standing to sitting
- Going from sitting to lying
Although these are simple activities, you must learn to do them safely so that the hip does not dislocate or suffer other injury.
Another important goal for early physical therapy is for you to learn to walk safely with an appropriate assistive device (usually a walker or crutches). Your surgeon will determine how much weight you can bear on your new hip, and your therapist will teach you the proper techniques for walking on level surfaces and stairs with the assistive device. Improper use of the assistive device raises the chance for accident or injury.
The occupational therapist will also visit with you to teach you how to perform activities of daily living safely. They will provide you with a list of hip precautions which are designed to protect your new hip during the first 8-12 weeks following surgery.Precautions
- Do not bend forward to reach your feet. You must maintain a 90 degree angle between your torso and legs.
- Do not lift your knee higher than your hip on the operated side.
- Do not cross your legs.
- Do not allow your legs to internally rotate (feet turned in).
- Do not twist while lying or standing.
- Sleep on your back with a pillow between your knees to prevent crossing.
- Strictly observe your weight bearing precautions during standing or walking.
Also, the occupational therapist will instruct you in the proper use of various long-handled devices for activities of daily living. These devices may include the following:
- A reacher to dress and pick things up from the floor.
- A sock-aid that will assist in putting on socks.
- A long-handled sponge to wash your legs and feet.
- A leg-lifting device to move the operated leg in and out of the car or bed.
- An elevated toilet seat so that you don’t violate your hip precautions when using the bathroom.
- An elevated bathtub chair to fit in the shower or tub.
Following surgery, a physical therapist may help you with your rehabilitation protocol. In addition to the exercises done with the therapist, you should continue to work on the hip exercises in your free time. It is also important to continue to walk on a regular basis to further strengthen your hip muscles. An exercise and walking program helps to enhance your recovery from surgery and helps make activities of daily living easier to manage.
While at home, you will continue to walk with the assistive device unless directed by your surgeon to discontinue use. You must also remember to strictly follow the hip precautions and weight bearing instructions during the first few months following surgery. It is recommended that you not drive unless you have been approved by your doctor.Life After Hip Resurfacing Surgery
After you have completed your hip rehabilitation, you should experience improved range of motion and have strength in your hip to return to most everyday activities. Below are a few warnings to keep in mind after your hip resurfacing surgery. Remember to listen to what your body tells you. If you begin to have pain or swelling, contact your physician for advice.
Take care to protect your new hip from too much stress and follow your surgeon’s instructions regarding activity level.
Do not perform high impact activities such as running and jumping during the first year following your surgery to allow your hip bones to heal properly. While that same study of 2,385 BIRMINGHAM HIP resurfacing patients found that less than one-half of one-percent of patients experienced a femoral neck fracture in the first five years after surgery, the average time this fracture took place was just two and a half months after their surgery. Other studies have shown a fracture rate of up to 1.4-percent.
Early device failure, such as breakage or loosening, may occur if you do not follow your surgeon’s limitations on activity level. Early failure may occur if you do not protect your hip from overloading due to activity level or fail to control your body weight. Accidents such as falls may also cause early device failure.
As with any major surgical procedure, post-operative complications can occur following hip resurfacing surgery. Below is a list of some of the more common complications that can occur after hip resurfacing surgery. This list is not meant to be all-inclusive.Thromboembolism
This condition, which includes two interrelated conditions—deep vein thrombosis and pulmonary embolism—occurs when blood clots are formed in the large veins of the legs. In some cases, these clots can become dislodged from the veins, travel through the circulatory system, and become stuck in the critical arteries of the lungs. This scenario, called a pulmonary embolism, is a serious medical condition.
The following steps may be taken by you and your physician to avoid or prevent thrombois:
- Blood-thinning medication (anticoagulants, aspirin)
- Elastic stockings (TED hose)
- Foot elevation to prevent swelling
- Foot and ankle exercises to optimize blood flow.
- Pneumatic devices placed on the feet to improve circulation.
IMPORTANT: If you develop swelling, redness, pain and/or tenderness in the calf muscle, report these symptoms immediately to your physician.Infection
Infections occur in a small percentage of patients undergoing hip resurfacing surgery. Unfortunately, infections can occur even when every effort is made to prevent them.
The following steps may help to minimize the risk of post-operative infections:
- Closely monitor the incision and immediately report signs of redness, swelling, tenderness, drainage, foul odor, increasing pain or persistent fever.
- Always wash your hands before and after handling your incision site, especially when the sutures are still in place.
A possible side effect of surgery is the development of pneumonia.
The following steps may help minimize this risk:
- Deep breathing exercises A simple analogy to illustrate proper deep breathing is to: “smell the roses...and blow out the candles.” In other words, inhale slowly and deeply through your nose, and exhale slowly through your mouth at a slow and controlled rate. A simple rule of thumb may be to perform these deep breathing exercises 8-10 times every waking hour.
- Coughing This activity helps to loosen the secretions in your lungs and excrete them from your pulmonary system.
- Incentive spirometer This simple device provides visual feedback while performing deep breathing exercises. Your nurse or respiratory therapist will demonstrate the proper technique.
Since the BIRMINGHAM HIP Resurfacing implant is new in the United States, is it clinically proven?
While the BIRMINGHAM HIP Resurfacing implant is new to the United States, it is not a new implant or technique. It has been in use worldwide since 1997, and the US Food and Drug Administration reviewed a tremendous amount of resulting clinical data before approving it for use in this country.
Who is a candidate for the BIRMINGHAM HIP Resurfacing System?
The typical patient will be physically active, under 60 years of age, and suffering from hip arthritis, hip dysplasia or avascular necrosis of the hip. The implant can be used in patients over 60 whose bone quality is strong enough to support the implant. Your surgeon will make the determination if you are a candidate for hip resurfacing.
How long will the BIRMINGHAM HIP Resurfacing implant last?
It is impossible to say how long your implant will last because so many factors play into the lifespan of an implant. In the case of resurfacing, for instance, the metal-on-metal bearing surfaces of your new joint may extend its life longer than that of a traditional total hip replacement, but failure to comply with your physical rehabilitation regime may cause your implant to fail within months. A clinical study showed the BIRMINGHAM HIP Resurfacing implant had a survivorship of 98.4-percent at the five-year mark, which is comparable with the survivorship of a traditional total hip replacement in the under-60 age group.
How long will my scar be?
Your surgeon will use an incision of between six and eight inches in length. While some surgeons may use a slightly smaller incision, most will fall in that range.
What are my physical limitations after surgery?
Most surgeons will tell you that after the first year, you can return to whatever physical activity you enjoyed before hip pain limited your mobility. For instance, unlike total hip replacement, you will be able to return to jogging or singles tennis after your first year after surgery. During your first year, more conservative, low-impact activities like walking, swimming and bicycling are recommended for strengthening your femoral neck and the muscles around your resurfaced joint.
How can I receive more information about hip resurfacing and the BIRMINGHAM HIP implant?
Ask your surgeon for BIRMINGHAM HIP Resurfacing System patient information, or visit www.BirminghamHipResurfacing.com.
For more information about the BHR Sysem, visit www.BirminghamHipResurfacing.com.
VERILAST™ Knee Technology
The brightest minds at orthopedic medical technology company Smith & Nephew have worked for years to minimize concerns about a leading cause of knee replacement failure—implant wear. While scientific literature indicates knee replacements should be expected to last 10 to 15 years before wear becomes an issue, Smith & Nephew has always thought they could do better for physically active patients.
So they invented VERILAST™ Knee Technology — a combination of remarkable materials that were tested to simulate 30 years of wear performance. That’s more than twice the length of testing of knee replacements made from traditional materials, cobalt chrome metal and high density plastic.
So while they cannot say they've eliminated a leading cause of implant failure, Smith & Nephew believes their 20 years of dedicated research are paying off for patients who would like to redicover their active life after surgery.About Knee Replacement Surgery
There are potential risks with knee replacement surgery such as loosening, fracture, dislocation, wear and infection that may result in the need for additional surgery. Do not perform high impact activities such as running and jumping unless your surgeon tells you the bone has healed and these activities are acceptable. Early device failure, breakage or loosening may occur if you do not follow your surgeon’s limitations on activity level. Early failure can happen if you do not guard your knee joint from overloading due to activity level, failure to control body weight or accidents such as falls. Knee replacement surgery is intended to relieve knee pain and improve knee functions. Talk to your doctor to determine what treatment may be best for you. Additional information is available at www.RediscoverYourGo.com
Remember, VERILAST™ Knee Technology is exclusive to medical device maker Smith & Nephew—and not every surgeon has been trained to use Smith & Nephew knee implants. I have received that training and look forward to discussing the VERILAST◊ Technology option with you.Technology
VERILAST™ Knee Technology builds on the decade of success of an advanced implant material called OXINIUM◊ (Oxidized Zirconium), joining this lightweight, low-friction metal with a special kind of "highly cross-linked" plastic that is also resistant to common implant wear. When these two surfaces work together in the joint, they do amazing and unprecedented things:
- In rigorous lab testing, Smith & Nephew’s LEGION◊ CR knee replacements made from exclusive VERILAST◊ Technology were subjected to 45 million simulated "steps." That's equal to around 30 years of physical activity under typical conditions.
- The testing showed that after 5 million steps, LEGION◊ CR knees made with VERILAST◊ Knee Technology reduced 98% of the wear experienced by knees made with traditional implant materials. And when the knees made with VERILAST™ Technology kept "walking" out to 45 million cycles, it reduce 82% of the wear experienced by the traditional material knee implant that was stopped after the first 5 million cycles.
Based on laboratory wear simulation testing, the LEGION◊ Primary Knee System with VERILAST◊ Knee Technology is expected to provide wear performance sufficient for 30 years of actual use under typical conditions.
The results of laboratory wear simulation testing have not been proven to predict actual joint durability and performance in people. A reduction in wear alone may not result in improved joint durability and performance because other factors, such as bone structure, can affect joint durability and performance and cause medical conditions that may result in the need for additional surgery. These other factors were not studied as part of the testing. So while they cannot say they’ve eliminated a leading cause of implant failure, Smith & Nephew believes their 20 years of dedicated research are paying off for patients who would like to rediscover their active life after surgery.
* Trademark of Smith & Nephew.