Rehab After Partial Knee Replacement

Partial knee replacement is a treatment for severe arthritis of the knee joint. It can be an alternative to total knee replacement in certain situations. A partial knee replacement is a more limited procedure than a total knee replacement, and it involves a faster recovery. You might be a candidate for a partial knee replacement if your knee arthritis isn't extensive. Also, there's some evidence that a partial knee replacement does not last as long as a total knee replacement.

Learn more about the recovery and rehabilitation process after a partial knee replacement.

Overview

The knee has three compartments. When damage is limited to a single compartment, a partial knee replacement can sometimes be an option. In these situations, only the damaged part of the knee joint is replaced.

Compartments are defined as:

• Under the kneecap, where you could have a patellofemoral replacement
• On the inner side of the joint (medial compartment),
• On the outer side of the joint (lateral compartment)

Many people who have knee arthritis have damage in multiple parts of the knee joint. When this damage extends to two or more compartments of the knee joint (tricompartmental arthritis) then the treatment is a full knee replacement.

Comparing Partial and Total Knee Replacement

For some people, partial knee replacement is a great option for surgical treatment of knee arthritis, but it is not always a suitable choice.

During a total knee replacement surgery, your orthopedic surgeon would remove your entire knee joint and replace it with an artificial implant. In addition to removing all of the cartilage of the knee joint, you would have quite a bit of bone and ligament tissue removed.

Partial knee replacement is limited to a smaller portion of the knee joint, removes much less bone, and leaves all of the normal ligaments intact.

The advantages of partial knee replacement include:

• Faster recovery
• Return to activities sooner
• More normal feeling knee
• Less pain
  

Day of Surgery

Partial knee replacement implants are stable as soon as they are implanted. Immediately following the surgery, patients can normally place as much weight on their surgical knee as they are comfortable with.

On the day of surgery, instruction begins for exercises to help with knee range of motion. Exercises will focus on regaining full extension (straightening) of the knee. Bending of the knee is allowed immediately following surgery.

You will also get instructions on the use of crutches or a walker. While you can safely place your full weight on your leg, ambulatory aids are needed for safety until balance and stability are back to normal.

Hospitalization

Sometimes, a partial knee replacement is done as an outpatient procedure, which means that you would come into the hospital in the morning, and leave to return home that same day. Most often, people will spend a night in the hospital and go home the following day.

It is typically not necessary to spend more than one night in the hospital following a partial knee replacement. While in the hospital, you would start working with a therapist and practicing the tasks (stairs, chairs, toileting) you will need to perform once you are back home.

1 to 2 Weeks After Surgery

During the first few weeks, it is important to pay attention to specific instructions from your surgeon. These may include instructions to ensure healing of the incision. Some people may need sutures or staples removed from their incisions. You may have specific bandage requirements and recommendations about when you can get the incision wet.

Early efforts to strengthen the knee can begin, but the focus should be on motion and pain control.

The goals of rehabilitation in the first one to two weeks following surgery are to:

• Manage symptoms of pain and swelling
• Improve walking mechanics and stability
• Ensure that range of motion is from full extension to 90 degrees of bending
  

3 to 6 Weeks After Surgery

Once you stop using ambulatory aids, you can begin walking and gradually increasing the duration of your walks. Bending the knee should continue to progress beyond 90 degree during weeks three and four.

You should begin low-impact, aerobic exercise activities, such as stationary bicycling.

Typically by six weeks post-surgery, people can resume most normal activities and can start doing light exercises.

Long-Term Results

Partial knee replacements tend to feel like a normal knee, even years after the surgical procedure. By preserving the healthier parts of the knee joint, and not removing as much of the soft tissue structures surrounding the knee, people who have a partial knee replacement have more normal mechanics of the knee joint than after a total knee replacement.

Partial knee replacements have been done for a number of decades. Initially, they were popular because of the faster recovery, but they began to fall out of favor because the longer-term results were less successful than the results of total knee replacements.

With improved techniques and implant materials, partial knee replacements are becoming more popular again. A partial knee replacement can be a stepping stone to ultimately needing a full knee replacement, but many patients have very good intermediate to long-term results with a partial knee replacement.

How Long Does a Partial Knee Replacement Last?

Just as a total knee replacement can wear out over time, partial knee replacements can also wear out. The longevity of a partial knee replacement has always been considered to be inferior to a full knee replacement.

Reasons for the shorter longevity:

• People who have partial knee replacements often expect more of their knee and place more stress on the knee joint through increased activity.
• Partial knee replacements do not allow for correction of alignment deformities of the knee and may wear out as a result of misalignment.
• The rest of the knee joint that was not replaced can wear out over time, and the partial knee replacement may not control arthritis progression.

Some people choose to have a partial knee replacement changed to a full knee replacement. Recent studies have shown reasonably good results when people need to have a partial knee replacement converted to a full knee replacement.

A Word From Verywell

Partial knee replacement is a treatment option for people who have severe arthritis of the knee joint limited to one specific area within the knee. One benefit of partial knee replacement is a faster recovery. Rehab timelines are generally about twice as fast when compared to a recovery timeline following a full knee replacement. Many people who undergo partial knee replacement have resumed most of their normal activities within six to eight weeks of the surgical procedure.