A common issue with joint replacement is what surgeons refer to as "wear". Any time two moving parts rub against each other repeatedly, friction occurs. This causes scratches which make tiny fragments of material come off over time. This effect - not unlike the action of a fingernail file - is a main reason why joints "fail", and an individual will undergo repeat surgery.

The OXINIUM material has proven to be a superior metal for use in the production of knee and hip implants due to its hardness, smoothness and resistance to scratching and abrasion. The superior strength results in less wear than cobalt chrome (historically the material of choice in knees and hips) and more toughness than ceramic (an alternative material for hips)

Some facts that may interest you:

• The OXINIUM material is 4,900 times more abrasion resistant that cobalt chrome, and reduces wear by 85% in knees and up to 98% in hips.
• The OXINIUM material contains no detectable nickle, the leading cause of negative reactions in patients with the metal allergies.

    

Why Does My Hip Hurt?



In a healthy, normal hip, the movement of bending, straightening, or rotating is absorbed by the cartilage, allowing the ball to move freely in the socket without pain. Over time, however, the cartilage can wear away or get damaged causing the bones to rub and grind together. This causes much of the pain and stiffness patients feel.

Although people frequently associate joint pain with an injury or fracture to the hip, other common causes of a damaged hip include the breakdown of the joint's cartilage (osteoarthritis); inflamed and stiff cartilages (rheumatoid arthritis or gout); and decay of the bone from long-term use of alcohol or steroids (necrosis).

What Is Total Hip Replacement?



In total hip replacement surgery, the painful parts of the damaged hip are replaced with artificial hip parts called a prosthesis, a device that substitutes or supplements a joint. The prosthesis consists of three components: a socket, ball and stem. The outer shell of the socket is usually made of metal and the inner shell consists of plastic, or the entire socket may be plastic. When the metal ball is joined with the socket, the new hip allows for smooth, nearly frictionless movement.

How Will I Know If I Should Have Hip Replacement?

The orthopaedic surgeon will perform a very thorough examination of your hip by performing physical tests and analyzing x-rays, as well as taking your medical history.

The surgeon will ask you to describe your pain and ask questions to determine other joint problems and how past injuries might have affected your current hip. You will also be asked to tell how you've treated your pain in the past, whether it be through physical therapy or by taking medications.

Your joint will be tested for strength and range of motion. At this time, the surgeon will observe how you walk and bend, and watch for any problems in the way you move.

X-rays will provide your surgeon with images of your hip joint to show changes in size, shape, or unusual circumstances to determine if surgery would be the best option. If so, the x-rays will also help in the sizing and fitting of your new hip.

Based on this examination, your surgeon will determine whether you are a candidate for total hip replacement. Although widely practiced, total hip replacement is a major surgical procedure and should only be considered when all other treatment methods have failed. There are more conservative alternatives which you and your surgeon may want to consider. These include medications or injections for pain and inflammation, physical therapy, or other types of surgery.

The final decision about whether or not to have total hip surgery will be yours, so you will want to understand the risks involved. There are potential complications both during and after surgery. Generally, these include infection, blood cots, pneumonia, dislocation, prosthesis loosening, and nerve damage. Your surgeon can answer your specific questions about these risks.

What Is It Like To Have Total Hip Replacement Surgery?



Before Surgery

If you and your surgeon decide that total hip replacement is right for you, a date will be scheduled for your surgery. Several things may be necessary to prepare for surgery. For example, your surgeon might ask you to have a physical examination by your primary care physician.

You should also finish any dental work that may be underway to prevent germs in your mouth from entering the bloodstream and infecting the new joint. If you prefer, or if your surgeon feels it is needed, you may want to donate your own blood ahead of time to reduce the risk of your body reacting to the blood transfusion

During Surgery
On the day of surgery, an intravenous tube will be inserted into your arm to administer necessary medications and fluids during surgery. You will then be taken to the operating room and given anesthesia.

The surgery usually takes two to four hours, although this is dependent upon the severity of the arthritis in your hip. In the operating room, urinary catheter will be inserted and left in place for one or two days. Compression stockings and pneumatic sleeves will be put on both legs.

The procedure is performed through an incision over the side of the hip. The ball-end of the thighbone (femur) is cut and replaced with the new metal ball and stem component. It may be stabilized with or without cement. The damaged surface of the socket is smoothed in preparation for the insertion of the new socket. The ball and socket are then joined. When the surgeon is satisfied with the fit and function, the incision will be closed and covered with dressings. You will also find small drainage tubes coming out of the hip to drain fluid from the wound.

After Surgery
You will be sent to the recovery room and as the anesthesia wears off you will slowly regain consciousness. A nurse will be both with you, and may encourage you to cough or breath deeply to help clear your lungs. You will also be given pain medication and will find a foam wedge or pillows placed between your legs to help hold your joint in place. When you are fully conscious, you will be taken back to your hospital room.

What Can I Expect After Surgery?



When you are back in your hospital room, you will begin a gentle rehabilitation program to help strengthen the muscles around your new hip and regain your range of motion. On the day of surgery you may be asked to sit on the edge of the bed and dangle your feet. You will also learn how to protect your new hip while doing daily activities.

As soon as possible, usually within the next 24 hours, your physical therapist will help you start walking a few steps at a time. As you heal you will progress from walker to crutches and then a cane. Before you are dismissed from the hospital, an occupation therapist will also show you how to perform daily tasks at home with your new hip. For example, he or she will instruct you on how to go to the bathroom, how to dress yourself, how to sit or stand, how to pick up objects and many others.

After about two to four days, or when your surgeon determines that you have recovered sufficiently, you will be discharged. You may be transferred to a nursing facility for a few more days, as determined by your surgeon. Upon returning to your home, you will need to continue taking your regular medications and continue exercising as directed by your surgeon or physical therapist. Walking, remaining active and practicing the required exercise are the quickest ways to full recovery. Within six weeks, you will revisit your surgeon at the hospital to check up on the progress of your recovery.

In most cases, succesful total hip replacement will relieve your pain and stiffness, and allow you to resume many of your normal daily activities.But even after you have fully recovered from your surgery, you will still have some restrictions. Normal daily activities do not include contact sports or activities that put excessive strain on your hips. Although your artificial hip can be replaced, a second implant may not be as effective, and your activities would likely be even more restricted. Questions about your specific situation are best discussed with your surgeon.

Why Does My Knee Hurt?



Your knee joint is made up of three bones. Your thigh bone (femur) sits on top of your shin bone (tibia). When you bend or straighten your knee, the rounded end of your thigh bone rolls and glides across the relatively flat upper surface of your shin bone. The third bone is often called the kneecap (patella), which is attached to the muscles that allow you to straighten your knee. Your kneecap provides leverage that reduces strain on these muscles.

In a normal, healthy knee, the bone surfaces that come together at the joint are smooth and hard. A cushioning layer of tissue, called cartilage, prevents direct contact among these bones. This tough layer of tissue allows the three bones to move without creating friction or wear on the bone surfaces.



However, when this cartilage is damaged or worn away, your bones rub together causing friction, pain and, eventually, deterioration of the bone surfaces. The most common causes of damage to your cartilage are the various types of arthritis. There is no medication or treatment that will make damaged cartilage grow back.

What Is Total Knee Replacement?



In total knee replacement surgery, the parts of the bones that rub together are resurfaced with metal and plastic implants. Using special, precision instruments, your surgeon will typically remove the damaged surfaces of all three bones. The replacement surfaces will then be fixed into place.

The surface of the upper bone is replaced with a rounded metal component that comes very close to matching the curve of your natural bone. The surface of the lower bone is replaced with a flat metal component with a slab of ultra-high-molecular-weight polyethylene plastic to serve as the cartilage. The undersurface of the kneecap may also be replaced with a round disc made of the same polyethylene plastic.

How Will I Know If I Should Have Knee Replacement?

Your orthopaedic surgeon will perform a very thorough examination of your knee. This will include a test of your range of motion-how far you can bend and extend your knee. Your surgeon will also look deformities in your legs which may show up as conditions commonly called bowlegged or knock-kneed. You will be asked to walk, sit and perhaps go up and down a few steps.

Your surgeon will also ask you many questions to determine your medical history. You will be asked about injuries, infections and other disorders you have experienced in your life. Your surgeon will want to know what medications are you taking. And, of course, you will be asked to describe the pain in your knee.

Finally, your surgeon will take x-rays which will be used to further assess the condition of your knee joint. If you decide on total knee replacement surgery, these x-rays will also be used to help your surgeon select the best type and size of artificial knee.

Based on this examination, your surgeon will determine whether you are a candidate for total knee replacement. Although widely practiced, total knee replacement is a major surgical procedure and should only be considered when all other treatment methods have failed. There are more conservative alternatives which you and your surgeon may want to consider. These include medications or injections for pain and inflammation, physical therapy, or other types of surgery.

The final decision about whether or not to have total knee surgery will be yours, so you will want to understand the risks involved. There are potential complications both during and after surgery. Generally, these include infection, blood cots, pneumonia, prosthesis loosening, and nerve damage. Your surgeon can answer your specific questions about the risks.

What Is It Like To Have Knee Replacement Surgery?

Before Surgery
If you and your surgeon decide that total knee replacement is right for you, a date will be scheduled for your surgery. Several things may be necessary to prepare for surgery. For example, your surgeon might ask you to have a physical examination by an internist or your regular doctor.



Because blood transfusions are likely to be needed during your surgery, you may want to donate one unit of your own blood, or possibly two units if your surgeon feels it is needed. You can donate one unit per week before your surgery.

During Surgery
On the day of surgery, a small tube (intravenous line) will be inserted into your arm. This tube will be used to administer antibiotics and other medication during your surgery. You will be taken to the operating room and given anesthesia. After the anesthesia takes effect, your knee will be scrubbed and sterelized with a special solution.

The surgery will begin with an incision over the knee that will expose the joint. When the bones are fully visible to the surgeon, special, precision guides and instruments are used to remove the damaged surfaces and shape the ends of the bones to accept the implant.

The implants are then secured to the bones. It might also be necessary to adjust the ligaments that surround the knee in order to achieve the best possible knee function. When the surgeon is satisfied with the fit and function of the implants, the incision will be closed.

A special drain may be inserted into the wound to drain the fluids that naturally develop at the surgical site. A sterile bandage will then be applied, and you will be taken to the recovery room, where you will be closely monitored. Your surgery will likely take between one and three hours, depending on your individual circumstances.

After Surgery
As your anesthesia wears off, you will slowly regain consciousness. A nurse will be with you, and may encourage you to cough or breath deeply to help clear your lungs. You will also be given pain medication. When you are fully awake, you will be taken to your hospital room. Your knee will remain swollen and tender for a few days.

What Can I Expect After Surgery?

When you are back in your hospital room, you will begin a rehabilitation program that will help you regain strength, balance, and range of movement in your knee. This program will be designed specifically for you. It may include a machine, called a continous passive motion machine, that automatically moves your leg to help reduce stiffness.

Your physical therapist will help your perform appropriate exercises. About 24 hours after surgery, you will probably be asked to stand. Within the next 24 hours, you will begin to walk a few steps with the help of a walker.

You will be discharged as soon as your surgeon determines that you have recovered sufficiently. You can expect to stay in the hospital for about three days after your surgery. You may or may not be transferred to a nursing facility for a few more days, as determined by your surgeon. Your bandages and sutures will usuallybe removed before you leave the hospital.

At home, you will need to continue your exercises. Your physical therapist will instruct you about proper home care, and may continue to work with you.

Within six weeks after surgery, most patients are able to walk with a cane. You will probably feel well enough to drive car within seven to eight weeks after surgery.

In most cases, successful total knee replacement will relieve your pain and stiffness, and allow you to resume many of your normal daily activities. But even after you have fully recovered from your surgery, you will still have some restrictions. Normal daily activities do not include contact sports or activities that put excessive strain on your knees. Although your artificial knee can be replaced, a second implant is seldom as effective as the first.

        

Why is CAS, and how is it different from conventional procedures. What are the unique characteristics of CAS.



The Computer Aided Surgery (CAS) is an advance medical navigation technology that enchances surgical processes and outcomes. Its marked improvement of surgical precision has been clinically proven in the fields of neurosurgery, ENT surgery and spinal surgery. The orthopedic surgical community is rapidly recognizing the many benifits of CAS for patients, doctors and hospitals.
After registration, patient specific and precise anatomical information (the complete knee joint structure) can be obtained without CT scan in a small incision for every individual surgery through BrainLAB advance bone morphing technology. The bone cut accuracy can be up to 0.1mm to 0.1degree. With the information provided by the computer, surgeons can make the decision without the assessment if inner bone structure and exactly where to cut the bones.
Provide extra information that can't be given with conventioanl tools.

Applications

• Total Knee Replacement Surgery.
• Total Hip Replacement Surgery.
• Hip Resurfing Surgery and many more.

What is my benefits in using CAS, and how does it help me.

• Accuracy and reduced revision rate.

The succsess of a total knee surgery highly depends on the accurate bone cut and prosthesis position. Research shows that only 3mm displacement from accurate position will lead to drastically increase the ligament tension by 240% i.e. increase leg tension.

-Navigation helps to determine the most accurate bone cit position, predict surgical outcome before surgery and have the best surgical solution.

-Accurate bone cute contributing to longer implant life cycle and reducing the revision rate.

Enhance Minimally Invasive Surgery (MIS).



Navigation's accuracy further enhances the MIS. MIS is a form of surgery that allows a smaller wound and incision for the surgery, minimizing trauma to the soft tissue. With MIS the patient experiences.

-Less post-operative pain as there are no large incisions.

-Minimal scarring thus better cosmetic results.

-Faster recovery and able to return earlier to normal activities.

Less bleeding.

Intra-medullary rod is used to determine the bone cut position in conventional total knee replacement surgery by inserting the into the femur. This may increase the bleeding and chance of fat embolism. Fat embolism is a serious condition that occurs when fat droplet, usually from the bone marrow, enter the blood stream affter femoraltrauma by the intra-medullary rod.

With navigation, there is no need to insert the Intra-medullary rod into the femur anymore which means

-Less bleeding.

-Less chance of fat embolism.

• Documentation of surgical result after surgery as your personal life long medical record.

What are the potential complications and risk caused by using CAS?

• None

What are the pre/post-operative preparations required?

• Same as conventional surgery

Zimmer NexGen® Complete Knee Solution

If you are among the approximately 30 million Malaysians who suffer from osteoarthritis, severe knee pain may be an everyday reality. Climbing stairs, kneeling to pray, gardening, golfing, bowling, or even just getting a full night's sleep are activities you may no longer be able to do without experiencing pain.

Many people who are candidates for knee replacement surgery may be reluctant to take that step, fearing that further limitations on knee flexibility often following surgery may limit daily activities. Today, two high flex total knee replacement implants are available for patients with the ability and desire to perform deep knee bending activities.

The Zimmer NexGen® Complete Knee Solution LPS-Flex Fixed Bearing Knee and the CR-Flex Fixed Bearing Knee are high flex fixed knee implants for people who want to continue their replacement. They are specifically designed to safely accommodate deep flexion of up to 155 degrees.

Flexion is the action of bending a joint, such as your knee or elbow. The opposite motion is extension, which is the straightening of joint. Generally traditional knee replacements accommodate flexion up to 125 degrees. Many daily activities require a higher range of motion:

1. Climbing stairs - 75-140 degrees of bending
2. Sittiing in a chair - 90-130 degrees of bending

Gardening, golfing or activities such as kneeling for prayer and sitting cross-legged can demand up to 130-150 degress of bending.


With early diagnosis and good preoperative flexion, NexGen high flex fixed knees can help appropriate patients maintain their desired quality of life and activity level.

System Checklist

If you answer yes to any of the following questions associated with the osteoarthritis, talk to your doctor.

1. Do you experience aching in your knee(s) followed by periods of relative relief?
2. Do you experience pain after extensive use of the knee(s)?
3. Are you experiencing loss of mobility in your knee(s)?
4. Do you experience knee joint stiffness that tends to follow periods of activity such as sleeping or sitting?
5. Does your knee pain seem to increase in humid weather?

What Is Osteoarthritis?

The most common form of arthritis, osteoarthritis is a degenerative joint disease that causes deterioration of the cartilage between bones. Factors that may cause the development and progression of the disease include aging, genetics, obesity, and joint injuries from sports, work or accidents. Knee osteoarthritis usually affects the weight bearing sections of the knee, which include the junction of the lower leg bone (tibia) with the upper leg bone (femur), and beneath the kneecap (patella).

A healthy knee is designed to move and endure the forces of everyday activities. Cartilage that covers the ends of our bones acts like a cushion or shock absorber to prevent joints from coming into direct contact. For those who suffer from osteoarthritis of the knee, the cartilage of the affected joint is roughened and becomes worn down, causing pain when the bones grind against each other. Indivduals with osteoarthritis may experience aching, stiffness and eventual loss of mobility within the knee joint. Inflammation may or may not be present.

While anti-inflammatory drugs, cortisone injections, and physical therapy are short-term solutions to manage the pain, many people eventually require knee replacement surgery.



Healthy knee



Knee with osteoarthritis

How Do I Know If I Am A Candidate For A NexGen High Flex Knee?

A common view among orthopaedic surgeons is that patients with good flexion before surgery tend to get better range of motion results after surgery. Candidacy for NexGen high flex knee is based on a number of factors, including:

1. A need and desire to perform high-flexion activities
2. Capability of 110 - 120 degrees of knee flexion prior to surgery
3. Willingness to undergo the rehabilitation necessary to regain flexion
4. Weight and activity level

You should discuss this question with your orthopaedic surgeon to assess whether the high flex knee is the best option for you.

What Test Will Confirm The Diagnosis of Knee Osteoarthritis?

Osteoarthritis is often visible on X-rays. Cartilage loss is indicated if the normal space between the bones is narrowed, if there is an abnormal increase in bone density or if bony projections or erosions are evident. A blood test is often taken to rule out rheumatoid arthritis. Your surgeon will conduct an examination of your knee, including range of motion and detection of deformities such as "knock-kneed" or "bow-legged". You will be asked to describe the pain in your knee.

Your physician also will record your medical history, often asking you a series of questions about injuries, infections, ailments you have experienced and any medications you are taking.

What Happen During High Flex Fixed Knee Replacement Surgery?

Surgery for a NexGen high flex knee is similar to other total knee replacements.

After anesthesia, your knee is sterilized, flexed about 90 degrees, and securely held in place during surgery. An incision is made that typically extends from just above the knee to just below the knee. The incision is gradually made deeper through muscle and other tissue until the bone surfaces are exposed.

The surgeon the removes the bone surfaces and cartilage damaged by osteoarthritis. Damaged bone surfaces are removed and the bone is shaped so the implants will fit properly. The amount of bone that is removed depends on the amount that has been damaged.

The implants are attached using a special kind of cement for bones. If necessary, the surgeon may adjust the ligaments that surround the knee function. NexGen high flex implants are designed so that the knee joint will move in a way that is similar to the way it moved when healthy.

When all implants are in place and the ligaments are properly adjusted, the surgeon restores tissue layers to their proper position and closes the area with stitches. A plastivc tube may be inserted into the wound to allow liquids to drain from the site during the first few hours after surgery. The knee is wrapped in a sterile bandage and the patient is taken to the recovery room.

Are These Special Pre-Operative Exercises I Should Do Before A Total Knee Replacement With A NexGen Knee?

Your doctor may recommend that you try and do some exercises in the weeks before surgery to help condition your muscles to support knee flexion when the new joint is implanted.

What Kind of Rehabilitation Program Should I Expect?

Since rehabilitation is crucial to a successful outcome, your doctor will likely recommend an early and aggressive rehabilitation regimen after surgery and after you leave the hospital. After discharge, your physician will refer you to a physical therapist who will work with you to help you regain your strength, balance, and range of motion. Your commitment to following proper prescribed home exercises and additional rehabilitation is essential to regain your ability to perform deep knee bending activities.