Knee Replacement FAQ
It’s important to understand the reasoning, procedure, and options behind a knee replacement. Here are some of the most frequent questions that patients ask.
Is knee arthroplasty different from knee replacement?
No. The terms can be used interchangeably. Total knee replacement is also called total knee arthroplasty. Similarly, a partial knee replacement is called uni-compartmental knee arthroplasty.
Is knee replacement surgery a fairly routine operation?
Yes. Hundreds of thousands of knees are replaced each year in the U.S., and world demand for knee replacements is increasing as people live longer and want more out of their lives.
Most orthopedic surgeons perform hundreds of knee replacements each year. While routine, knee replacement is still serious surgery. Each patient is unique, and each person’s anatomy demands careful attention to detail and precise steps during surgery.
Will a new knee joint be a perfect substitute for the real knee?
No, and you should be skeptical of any doctor or advertisement telling you otherwise. Those advertisements are designed to make a sale, rather than educate and enlighten consumers.
Normal human knee movement consists of gliding, rotation, sliding, and other complex movements. A synthetic joint can only approximate the intricacy and complexity of the knee joint that you were born with. No artificial knee joint, regardless of manufacturer’s advertising claims, or surgeon claims, has ever duplicated the complexity and intricate movements of the natural human knee.
The human knee joint has major ligaments and other soft tissue supports; these have fine nerve endings that send sensory, positional, and perceptual feedback to the brain from the knee. An artificial knee is simply metal and plastic. For severely diseased knees, modern total knee replacements provide excellent pain relief and function, but they are never a perfect substitute for the real thing.
What does an artificial knee feel like, if it does not feel natural?
Replacing your natural knee joint is a bit like replacing your natural teeth with dentures. Your own teeth are more than mechanical devices; they play a complex role in biting, chewing, hot-cold sensation, positional sense, vibration, and even taste.
Dentures are not natural or normal; they lack nerve endings and cannot feel vibration, heat, cold, touch, or any of the things we take for granted with our natural teeth. That is why dentures are useful only for patients whose own teeth are decayed or destroyed. Similarly, knee replacements are useful for patients with severe cartilage destruction, who have no other options, and who have thoroughly explored the possibilities.
How can I increase my chances of a successful knee replacement?
The success of knee surgery depends on your participation and how your body heals. Any operation on the human body has some uncertainty with respect to the outcome, despite the best of care.
Healing is a complex process, and each person heals differently. Knowledge and a strong partnership with your medical team leads to greater success, and makes it easier to work through any unexpected outcomes. The purpose of this website is to bridge the information gap and help you understand what questions to ask.
Can arthritis occur in a knee that is replaced?
No. Since cartilage is replaced by metal and plastic during knee replacement, there is no cartilage left in the knee to deteriorate. However, arthritis is a complex disease that frequently affects surrounding tissues, such as muscles, nerves, ligaments, and the synovial lining of the joint. This is one reason why despite a successful knee replacement, some pain, stiffness, and swelling may persist for many months.
In some patients, arthritis in other joints, such as the back and hip, can contribute to continuing symptoms after surgery. This is an important point to understand. Not all knee pain is from the knee; some may be coming from a diseased hip or spine, or other systemic illness like fibromyalgia or rheumatoid arthritis.
Stiff muscles, tendons, and ligaments can take many months to return to normal, even after healing from a knee replacement.
How long is the recovery after a total knee replacement?
Most patients are happy, mobile, and about 70 to 80 percent recovered by one month. Individual medical conditions such as diabetes, smoking, advanced age, obesity, neuropathy, heart and lung disease, Parkinson’s disease, and related variables can change recovery time drastically.
About 80 to 90 percent of the recovery is complete by six to eight weeks, but some aches and stiffness can persist for many months. The last 5 percent to 10 percent of soreness, achiness, and stiffness can take a year or two to subside completely.
For most patients, the most significant part of the recovery takes place during the first month. But keep in mind that patient variability is great; there is no value in comparing yourself with anyone else. Each person has a unique recovery.
Is recovery from knee surgery faster for younger patients?
No, and you should know about this paradox. Experience shows that the best recovery from knee replacement is in older patients, who have severe arthritis, and who have tried all reasonable conservative means of treating pain before surgery.
Younger patients, especially those of male gender and muscular physique, generally tend to have a noticeably slower recovery and higher level of pain from any knee surgery. This may reflect different expectations, different pain tolerances, body image, hypersensitivity of younger tissues, and other variables, but it is a fact that the younger patient should approach knee replacement surgery with added caution.
What is the best age for knee replacement surgery?
The optimal range is late 50s to late 70s. Most knee arthritis affects this age group, and a properly implanted total knee replacement should last the rest of life in such patients.
Should I get a second opinion before knee surgery?
Yes. If you have unanswered questions or doubts, additional opinions are always a good idea. A wealth of information exists on reputable websites. You can also learn a lot from orthopaedic implant companies as well as from friends, family, and others who have had knee surgery.
It is best to explore all your options and make your decision accordingly. Treat all information with a healthy dose of skepticism; any credible resource should be able to answer your questions to your satisfaction, no matter how authoritative or influential that resource holds itself to be.
A surgeon replaced my knee, and it did not work well. Can anything be done?
Usually, yes. Knee replacement surgery can be complicated by subtle infection, implant mal-positioning, and other unexpected outcomes that can leave patients unhappy. If this is the case, you should always seek a second opinion, even if a doctor has told you that nothing can be done. A variety of complex factors can compromise the results of knee replacements; fortunately, most such problems can be resolved.