The knee joint is one of the most complex joints of the body and takes the most stress of all the joints. Our knees absorb shock from walking and running and holding our body weight while standing. The knee needs at least 10 different muscles, plus bones, cartilage and ligaments, to work properly. Damage to the knee is common the older you get, especially if you are active in ways that put extra stress on the joint. Partial knee replacement surgery can relieve pain, give you back range of motion and have you back in the swing of things in no time.

Do I Need a Partial Knee Replacement?

A partial knee replacement (unicompartmental arthroplasty) is an alternative to total knee replacement for some people with osteoarthritis of the knee. This surgery can be done when the damage is only in one part of the knee. In a partial knee replacement, only the damaged part of the knee cartilage is replaced with an implant.

Partial knee replacement used to be for older patients who were involved in few activities. Now partial knee replacement often is done in younger people, as their recovery is quicker and usually less painful. The procedure is minimally invasive, and surgeons usually are able to preserve more healthy tissue, bone and ligaments in younger patients. About 5% to 6% of people with arthritic knees are estimated to be eligible for partial knee replacement.

If mobility issues are interrupting your daily life, you might be a good candidate for this procedure. The most common reason for this surgery is to relieve pain and restore the knee’s ability to move as it should. You might be a candidate for total knee replacement surgery if you have:

• Arthritis: Stress on the joint over a long period of time may lead to pain, swelling and stiffness in the knee.
• Knee injuries: An accident or sudden trauma can result in damage that requires surgery.
• Tumors: Some tumors are benign (harmless), while others are malignant (cancerous).

If the entire joint needs to be replaced, the doctor can use artificial parts to replace the entire joint. This is a total knee replacement. There are benefits and drawbacks to either type of knee replacement procedure, and your doctor will help you understand if a total or partial knee replacement is a better option for you.

Partial Knee Replacement Surgery

When a person has knee osteoarthritis, the cartilage protecting the bones of the knee slowly wears away. This can occur throughout the knee joint or just in a single area, or compartment, of the knee.

The knee is divided into three major compartments:

• Medial compartment (the inside part of the knee)
• Lateral compartment (the outside part of the knee)
• Patellofemoral compartment (the front of the knee between the kneecap and thighbone)

During the partial knee replacement, the damaged area is replaced with metal and plastic. The healthy cartilage and bone, as well as all of the ligaments, are left alone.

Knee replacement parts are made of different materials, including:

• Stainless steel
• Titanium and titanium alloys
• Cobalt and cobalt alloys
• Polyethylene
• Zirconium

These materials are medical grade, which means they are safe to use in humans and last a long time.

Two surgical methods we use at Norton Orthopedic Institute include:

• CORI Surgical System

The CORI Surgical System, a robotics-assisted knee replacement surgery tool, combined with the widest selection of implants available, allows your surgeon to place the new joint with an alignment that more closely matches that of your healthy knee.

The system’s 3D digital modeling is used to develop a surgical plan customized to the patient’s anatomy. This means Norton Orthopedic Institute surgeons can perform the procedure more accurately than with traditional knee replacement surgery.

• ROSA Knee System

Norton Orthopedic Institute has extensive experience with the ROSA Knee System, another robotics-assisted knee replacement tool.

In addition to its superior precision, the system uses lower-radiation X-rays to create a 3D model of the existing anatomy so surgeons can plan specifics of the replacement ahead of time.

Benefits of a Partial Knee Replacement

Most people who are good candidates for partial knee replacement have good results with this procedure.

The advantages of partial knee replacement over total knee replacement include:

• Quicker recovery
• Less pain after surgery
• Less blood loss
• Lower risk of infection and blood clots

Also, because the bone, cartilage and ligaments in the healthy parts of the knee are preserved, many patients report that a partial knee replacement feels more natural than a total knee replacement.

A disadvantage of partial knee replacement is the potential need for more surgery. For example, a total knee replacement may be needed later if you develop arthritis in the parts of the knee that have not been replaced. The need for additional surgery is slightly higher for partial knee replacement than for total knee replacement.

What to Expect With Partial Knee Replacement Surgery

After you check in at the hospital, you’ll be asked to remove your clothes and put on a hospital gown. Then you’ll be given either a spinal block, which numbs the lower half of your body, or a general anesthetic, which puts you into a sleeplike state.

Your surgeon also might inject a numbing medicine around nerves or in and around the joint to help block pain after your surgery.

During the Procedure

Knee replacement surgery usually takes one to two hours.

The surgeon will inspect the joint by first making a small incision (cut) at the front of your knee. They will then explore the three areas of your knee to verify that the cartilage damage is limited to one compartment and that your ligaments are intact.

If your surgeon feels that your knee is unsuitable for a partial knee replacement, they may instead perform a total knee replacement. Your surgeon will have discussed the possibility of this plan with you before your operation to make sure you agree.

The three steps in a partial knee replacement are:

• Prepare the bone. Your surgeon will use special tools to remove the cartilage from the damaged area of your knee.
• Measure and prepare the area. The surgeon replaces the cartilage and bone removed in the first step with metal coverings that recreate the surface of the joint. These metal parts typically are held to the bone with cement. Alternatively, in cementless fixation, the metal parts may be press-fit to the bone to allow bone to grow onto the implant.
• Insert a spacer. The surgeon places a plastic insert between the two metal components to create a smooth gliding surface.

After the Procedure

After surgery, you’ll rest in a recovery area for a short time. How long you stay in the hospital after surgery depends on your individual needs. Many people can go home the same day.

The risk of blood clots increases after knee replacement surgery. To prevent this complication, you may need to:

• Move soon after surgery. You’ll be encouraged to sit up and walk with crutches or a walker after you leave the recovery area.
• Apply pressure. Both during and after surgery, you might wear elastic compression stockings or inflatable air sleeves on your lower legs. The air sleeves squeeze and release your legs. That helps keep blood from pooling in the leg veins, reducing the chance that clots will form.
• Take blood thinners. Your surgeon might prescribe an injected or oral blood thinner after surgery. Depending on how soon you walk, how active you are and your overall risk of blood clots, you might need blood thinners for several weeks after surgery.
• Manage pain. You will have a instructions about how to manage pain, either with medicine or via other methods.

It’s likely that you’ll also be asked to do frequent breathing exercises and gradually increase your activity level. A physical therapist can show you how to exercise your new knee. After you leave the hospital, you’ll likely continue physical therapy either at home or in a clinic.

For most people, knee replacement provides pain relief, improved mobility and an overall better quality of life. Most knee replacements can be expected to last at least 15 to 20 years.

After recovery, you can engage in various low-impact activities, such as walking, swimming, golfing or biking. But you should avoid higher-impact activities, such as jogging, and sports that involve contact or jumping. Talk to your health care team about ways to stay active after knee replacement.

Care That’s Focused on You

• Minimally invasive procedures can have you home quickly with less pain and faster recovery.
• Sophisticated pain management aims to keep you comfortable and safe.
• We have a deep commitment to getting you moving again and managing your pain so you can keep up with your physical therapy.
• With 30 orthopedic locations in Louisville, Southern Indiana and surrounding communities, we have specialists near you.
• Communicate with your provider, manage appointments, refill prescriptions and more, anytime, from a computer or mobile device with a free MyNortonChart account.

Choose Norton Orthopedic Institute for Your Hip or Knee Replacement

• Same-day appointments are available with no referral required. When you’re ready to take care of the pain, you want to get started.
• Schedule your appointments online or call (502) 559-5500.
• Our fellowship-trained and board-certified orthopedic surgeons have the experience you can trust. They perform more than 800 hip replacements and 1,000 knee replacements every year.
• Robotic-assisted surgeries provide added precision when placing your new joint. This gives a more natural feel that more closely matches your unique anatomy. Minimally invasive techniques get you started on your recovery faster and often allow you to go home the same day as your surgery.
• Choose from 30 locations in Louisville and Southern Indiana for follow-up care.
• Norton Healthcare is the first health system in the nation to be recognized as an Advanced Orthopedic & Spine Center of Excellence by DNV.
• We help you get ready for surgery and through your recovery with educational programs available online and in person.
• Medicare, Medicaid and most major commercial insurance plans are accepted.
• Your free Norton MyChart account allows you to communicate with your provider, manage appointments, refill prescriptions and more from a mobile device or computer.