There are more than 100 different kinds of arthritic conditions that can affect the human body. Osteoarthritis, or degenerative joint disease, is the most common form of arthritis. Osteoarthritis causes the cartilage to wear away, eventually resulting in painful bone-on-bone contact.

The bones in a joint are covered with a tough, lubricating tissue called cartilage to help provide smooth, pain-free motion to the joint. As the layer of cartilage wears away, bone begins to rub against bone, causing the irritation, swelling, stiffness, and discomfort commonly associated with arthritis.

Total knee replacement replaces damaged cartilage and bone with an artificial surface. The replacement implants include a metal alloy on the end of the femur (thighbone) and polyethylene (plastic) on the tibia (shinbone) and patella (kneecap). The implants create a new, smoothly functioning joint that prevents painful bone-on-bone contact.

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. This can usually be done through a smaller incision and you may recover more quickly. Your surgeon will determine if this is the best option for you.

With a partial knee, only the damaged cartilage of the knee is replaced. The healthy parts are preserved. The benefits of this procedure include a smaller incision (3-4 inches, compared to 6-8 inches for total knee replacement, a quicker recovery, and less bone removal. Other advantages of partial knee replacement include faster recovery*1, lower cost*15, fewer and less severe complications when compared to total knee replacement*16-17

All implants have a limited life expectancy depending on an individual's age, weight, activity level, and medical condition(s). A partial joint implant's longevity will vary in every patient. It is important to remember that an implant is a medical device that is subject to wear, which may lead to mechanical failure. While following all of your surgeon's recommendations after surgery may enhance longevity, there is no guarantee that your particular implant will last for any specific length of time.

Since implants are mechanical devices, they are subject to conditions that can lead to mechanical failure. The most common reason for implant failure in knee replacements is implant loosening or implant wear that leads to loosening. Implant wear particles can react with the bone, causing thinning of the bone that can lead to implant loosening. In most cases, failed implants can be revised successfully; revision may include a total knee replacement.

Your surgeon will evaluate your health history, perform a physical examination, and take X-rays to decide if you are a candidate for this surgery. You must then decide if your discomfort, pain or stiffness, and overall loss of quality of life justify undergoing surgery. Generally, there is no harm in waiting to have surgery if conservative, non-surgical treatments are effective.

If your doctor recommends joint replacement, it is normal to have many questions about the procedure. Below are some of the questions you may want to discuss with your orthopedic surgeon.

  1. What are the risks and potential complications of knee replacement?
  2. How long will the procedure take?
  3. How long will I be in the hospital?
  4. When will I be able to resume normal daily activities?
  5. From which activities will I be permanently restricted?
  6. How much pain relief or increased mobility can I expect?
  7. Which implant have you chosen for my joint replacement?
  8. What are the clinical results of the implant system you have chosen?
  9. What, in your opinion, makes this implant the very best available implant for my condition?

Minimally invasive partial knee replacement is designed to shorten the traditional incision, lessen trauma to soft tissues, and reduce recovery time. The scar will be about 3-4 inches long on the side of your knee, unless you have previous scars, in which case your surgeon may use an existing scar. It is common for patients to notice some numbness around their scar.

Yes, you may have some numbness on the outside of the scar. The area around the scar may feel warm. Kneeling may be uncomfortable for a year or more. You may also notice some clicking when you move your knee as a result of the artificial surfaces coming together.

Proper preparation and a great attitude are the best ways to accomplish a rapid recovery from joint replacement. With the help of a physical therapist or trainer, get yourself as physically fit as you can before surgery. Proper nutrition, weight loss (if overweight), and an optimal medical condition can help avoid complications. See your physician prior to surgery to ensure your blood pressure, heart, and lungs are in good shape. Choose a surgeon who specializes in joint surgery, and go to a hospital that has a dedicated joint unit to provide you with excellent care. Be prepared to continue with your exercise program after surgery.

Most patients do not require blood after surgery. It is possible that you may require blood, however. If you so desire, you can donate your own blood, use the blood bank, or have your relatives donate blood for you.

In the past, a total knee patient could typically expect to stay anywhere from 3-7 days, followed by six weeks or more of difficult therapy before returning to normal activities. With minimally invasive partial knee surgery, some surgeons are finding that patients can be discharged in as few as one to two days, with significantly faster return to normal activities and less post-operative pain.

Most patients are able to go directly home after discharge. Your surgeon and the hospital staff will help you decide where to go after you are discharged and can make the appropriate arrangements.

Walking with support (cane, crutches, or walker) typically begins the day after surgery. Walking support may be continued for three to four weeks. The hospital can arrange for these devices as needed. If you have a walker, cane or crutches that you regularly use, please bring them to the hospital. Most patients can climb stairs after one or two days and are discharged to home at that time. Dancing, golfing, and other low-impact activities may be permissible between six to twelve weeks. Returning to your daily activities will depend somewhat on your individual circumstances. Consult with your surgeon or therapist for advice on acceptable activities.

The ability to drive depends on several factors, such as which leg had surgery and what type of transmission you have. If your left leg is your surgical leg and you have an automatic transmission, you could be driving as soon as two weeks after surgery. If your right leg is the surgical leg, or if you have a manual transmission, your driving could be restricted for as long as six weeks. You should not drive until cleared by your surgeon or therapist.

Yes, you will permanently be restricted from performing high-impact activities such as running, singles tennis, and basketball. You will also be restricted from performing contact sports, downhill skiing, and other high-impact activities.

Returning to work depends on your type of work. Office workers often return in two to three weeks, while patients with more strenuous jobs may require more time away from work. The timing of your return to work depends considerably upon your commitment to recovery. You should not return to work until cleared by your surgeon.

If you go directly home from the hospital you may need assistance with stairs, meal preparation, house cleaning, etc., during the first week or so, depending upon your progress.

That depends on various factors, including the type of surgery, your health, and your recovery. Typically, patients should be able to return to certain low-impact activities within weeks after surgery. Surgeons generally discourage patients from jarring, high-impact activities, such as running and strenuous sports permanently.

While uncommon, complications can occur during and after surgery. Complications include, but are not limited to infection, blood clots, implant breakage, malalignment, and wear, any of which can require additional surgery. Infection and blood clots are two of the complications that concern surgeons the most. To avoid these complications, surgeons may take various measures, including prescribing antibiotics and blood thinners before and after surgery. Although implant surgery is extremely successful in most cases, some patients still experience pain and stiffness. Factors such as the patient's post-surgical activities and weight can affect longevity. Be sure to discuss these and other risks with your surgeon.

Age is generally not a problem if you are in reasonably good health and have the desire to continue living a productive, active life. You should see your personal physician for an opinion about your general health and readiness for surgery.