Knee Replacement Information

You Don’t Need to Live with Knee Pain

The knee is a complex collection of bone, cartilage, ligaments, and fluid that lends strength, flexibility, and stability to everyday activities.  Knee pain can happen at any and can affect your general well-being and keep you from enjoying life’s simple pleasures, whether taking a morning walk, enjoying a bike ride, or playing with grandchildren.  If you’re currently suffering from knee pain brought on by arthritis, injury or other causes, Texas Health Center for Diagnostics & Surgery is the right choice for treatment options to get you back to your active lifestyle.

Each of our patients is unique, and whether you require physical therapy, medication, or total knee replacement surgery, our orthopedic team is equipped to recommend and provide the solution that’s best for you.  

These days, patients experience a much shorter recovery time for knee replacement – also known as total knee arthroplasty or TKA.  In fact, it’s not unusual today for patients to be back on their feet the same day as surgery, with one- or two-night hospital stays the norm.  Within weeks following surgery, most of our patients are back to their daily routines – returning to work and enjoying their favorite activities – with little disruption to their lives.

No doubt, knee replacement surgery has come a long way since it was first performed more than 50 years ago.  Since then, improvements in surgical materials and techniques have significantly increased its effectiveness.  Considered one of the most successful procedures in medicine, each year more than 700,000 knee replacement surgeries are performed in the United States according to the Agency for Health Research and Quality.  

What is total knee replacement surgery?

The purpose of knee replacement surgery is to resurface damage parts of the knee joint to relieve pain that can’t be controlled by other treatments.  During surgery, the kneecap is moved out of the way, and the ends of the thigh bone and shinbone are cut to fit the prosthesis.  The underside of the kneecap is also cut to allow room for the artificial joint.  The two parts of the artificial joint – made of metal, plastic or ceramic – are affixed to the bones and kneecap using a special bone cement.

The doctor will choose a knee replacement prosthesis based on weight, activity level, knee dimensions, and general health of the patient.  During surgery, which typically takes about two hours, the knee is placed in a bent position to expose all surfaces of the join.

What is the difference between total knee replacement and partial knee replacement surgery?

Partial knee replacement surgery is a less invasive alternative to total knee replacement.  At times, partial knee replacement is a better option for patients with arthritis pain confined to a limited area.  The procedure moves only the most damaged areas of cartilage in a specific area and replaces these surfaces.  Because partial knee replacement requires a smaller incision than traditional total knee replacement, recovery time is generally a matter of weeks, versus several months required for total knee replacement.

What are the signs I may need knee replacement surgery?

Many of our patients find that it’s a challenge to perform simple activities like walking or climbing stairs.  You may even begin to feel pain when you are sitting or lying down.  If nonsurgical treatments like medications and using walking supports are no longer beneficial, you may want to consider total knee replacement surgery.  It all starts with a consultation with an orthopedic team where your medical history will be taken, followed by a physical exam, and X-ray of the knee before receiving a diagnosis.  

A knee replacement surgeon at Texas Health Center for Diagnostics & Surgery may recommend knee replacement surgery if any or some of the following conditions exist:

• Knee pain fails to respond to medication, injections and physical therapy for six months or longer
• Knee pain becomes debilitating
• Knee discomfort prevents a good night’s sleep
• Arthritis in the knee has substantially damaged the joint
• Arthritis has resulted in decreased knee function
• Some tumors involving the knee 

What can I do to improve my chances for a good knee replacement result?

Although each patient is different, there are several things you can do to enhance the results of your knee replacement surgery.  Think about your recovery at home, and make sure you have a friend or family member to help after you get home – and remember arrange your belongings to reduce tripping hazards as you’re moving from place to place.

If your doctor has suggested you lose weight before surgery, change your diet – but maintain good nutrition both before and after surgery – and be as active as you can.  Ask your doctor about strengthening exercises you can do before surgery to reduce healing time.  If you’re a smoker, quit at least six weeks before your surgery.  Both improper nutrition and smoking can slow down your healing.

Last, if you haven’t seen a dentist in the past two years or have loose or broken teeth, make sure you see a dentist to evaluate your dental health before knee replacement surgery.  A bad tooth is a type of chronic infection.

Knee Replacement Decision, Moving Ahead

A decision to move forward with total knee replacement surgery should not be taken lightly and involves a thoughtful conversation with yourself, your loved ones, and your surgeon.  Ultimately, the decision lies with you based on the effect knee pain is having on your quality of life.  If your symptoms are keeping you from enjoying life to its fullest, total knee replacement surgery may be right for you.

How much is hip pain holding you back from enjoying life? If you decide that hip replacement surgery is the best option for you, the team at Texas Health Center for Diagnostics and Surgery is ready to help.

Answers to common questions about Total Knee Replacement (TKR)

How long does a TKR last?

A common reply to this question is that total joint replacement lasts 15-20 years. A more accurate way to think about longevity is via the annual failure rates. Most current data suggest that both hip and knee replacements have an annual failure rate of 0.5-1.0%. This means that if you have your total joint replaced today, you have a 90-95% chance that your joint will last 10 years, and an 80-85% that it will last 20 years. With improvements in technology, these numbers may improve.

What types of implants are there?

The orthopedic implant industry has developed a number of innovative technologies in an effort to improve the outcomes of TJA. In recent years, these technologies have been marketed directly to patients, which have increased awareness as well as confusion on what these different designs mean. The most important message is that while a certain manufacturer may claim that their design is better, almost all the available registry data (large collections of data from countries that track TJA) show that there is no clear advantage to any of these designs when it comes to improving outcomes.

Here are specific implant design terms:

Gender specific: This refers to a modified implant design that accounts for average anatomic differences between men’s and women’s knees. Most manufacturers have incorporated similar modifications in their newer designs, which allow for more sizing options so that the prosthesis can be more accurately fit the patient’s native anatomy and recreate the natural function of the knee.

Rotating platform: This refers to a plastic bearing that independently rotates on a metal tray on which it is seated. More often, the plastic bearing locks into the metal tray — referred to as a “fixed bearing.” Some theoretical advantages to the rotating platform concept when it was initially designed was that it could reduce the wear of the plastic bearing, reduce the rate of loosening of the metal parts, and better replicate how a patient’s knee works (kinematics). Most current data show that after 5-10 years in use, there does not appear to be any difference between rotating platform and fixed bearing designs in any of these outcomes.

Will my surgeon use a computer, robot, or custom cutting guide in my surgery?

There are many studies attempting to evaluate these emerging technologies and their influence on the success of surgeries. Each of these technologies has a specific goal that has fueled its development (i.e. more accuracy in implant placement, more efficient or faster surgery, etc.). To date, there appears to be both pros and cons to each of these technologies, but more research is required to determine what advantage, if any, these may offer. The best approach is to discuss this topic with your surgeon. You may want to know if they use one of these technologies, why they have chosen to do so, and what their experience has been in using it.

Can a partial knee/unicompartmental knee replacement (UKR) relieve my knee pain?

There are many kinds of arthritic conditions that can affect the human body. Osteoarthritis, or degenerative joint disease, is the most common form of arthritis. The bones in a joint are covered with a tough, lubricating tissue called cartilage (the cushion in the joints) to help provide smooth, pain-free motion to the joint. As the layer of cartilage wears away, bone begins to rub against bone (“bone-on-bone”), causing the irritation, swelling, stiffness, and discomfort commonly associated with arthritis.

In some patients, only one part of the knee is damaged, while the remaining parts are completely healthy. In these cases, it is possible to replace only the damaged part of the knee with a metal and plastic implant. With a partial knee, only the damaged cartilage of the knee is replaced. The healthy parts are preserved.

In the past decade, there has been a major increase in the use of unicompartmental knee replacement (UKR/partial knee replacement) as surgical techniques have been refined. UKR has shown to be a reliable operation for isolated unicompartmental arthritis. UKRs now account for 8% to 10% of knee replacement procedures. Recent studies have suggested excellent medium- and long-term results of UKR.

Overall, results have shown 85% to 90% survivorship at 10 years, with as many as 90% of patients reporting that they are very satisfied with the procedure and they have reported excellent subjective and objective outcomes. Recent studies suggest that unicompartmental replacement allows a high percentage of patients to return to pre-surgical sport and activity participation.