Rehab After Partial Knee Replacement

A Faster Treatment Timeline Compared to Total Knee Replacement

knee replacement rehab
 sturti / Getty Images 

Partial knee replacement is a treatment for severe arthritis of the knee joint, and an alternative to total knee replacement for some specific patients. During a total knee replacement surgery, your orthopedic surgeon will remove the entire knee joint, and replace this with an artificial implant. In addition to removing all of the cartilage of the knee joint, there is quite a bit of bone, and ligament tissue that is also removed when a total knee replacement is performed.  Partial knee replacement is limited to a smaller portion of the knee joint, and leaves all of the normal ligaments intact, and removes much less normal bone.

Overview

We generally separate the knee into three different compartments. One of these compartments is under the kneecap (patellofemoral compartment), another on the inner side of the joint (medial compartment), and one on the outer side of the joint (lateral compartment). 

It is often the case the people who have arthritis of their knee have damage that occurs in multiple parts of the knee joint. When this damage extends to all three compartments of the knee joint (tricompartmental arthritis) then the treatment is a full knee replacement.

However, when the damage is limited to a single compartment, there is sometimes an option to perform a partial knee replacement. In these situations, only the damaged part of the knee joint is replaced. The advantages of partial knee replacement include:

  • Faster recovery
  • More normal feeling knee
  • Less pain

Partial knee replacement is not the right treatment for many patients with knee arthritis, but there are some individuals who are good candidates for this surgical procedure. One of the advantages of the partial knee replacement is the fact that people can return to activities sooner and tend to have a faster recovery. Described here is the typical rehabilitation following partial knee replacement.

Day of Surgery

Partial knee replacement implants are stable as soon as they are implanted. It is normally the case that people can place as much weight on their surgical knee as they are comfortable immediately following the surgery.

On the day of surgery, patients undergoing partial knee replacement will be instructed on exercises to help with range of motion of their knee. They will focus on regaining full extension (straightening) of the knee. Bending of the knee is allowed immediately following surgery.

Instructions on the use of crutches or a walker can be given. While full weight can be placed on the leg, it is important to use ambulatory aids until walking mechanics have improved and balance is back to normal.

Hospitalization

Some patients undergoing partial knee replacement are having this surgical procedure performed as an outpatient. This means that they 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 a night in the hospital following a partial knee replacement. While in the hospital, people should be working with a therapist and practicing the tasks (stairs, chairs, toileting) that they will need to perform once they are back home.

1-2 Weeks After Surgery

The goals of the first one to two weeks following surgery are to improve walking mechanics and stability, ensure that range of motion is from full extension to 90° of bending, and manage symptoms of pain and swelling. Early efforts to strengthen the knee can begin, but the focus should be on motion and pain control.

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 incision. You may have specific bandage requirements and recommendations about when you can get the incision wet.

3-6 Weeks After Surgery

Once ambulatory aids have been discontinued, people can begin walking and gradually progressing the duration of their exercise. Bending the knee should continue to progress beyond 90° during weeks three and four.

People should begin low-impact, aerobic exercise activities including stationary bicycling and increasing the duration of walks. Typically by six weeks post surgery, people have resumed most of their normal activities and are doing light exercises.

Long-Term Results

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.

With improved techniques and implant materials, partial knee replacements are becoming more popular again.  While some people consider partial knee replacement a stepping stone to ultimately needing a full knee replacement, many patients seem to have very good intermediate to long-term results with a partial knee replacement.

As mentioned, partial knee replacements are often preferred by patients as they tend to feel like a more 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.

Unfortunately, not everyone is a good candidate for a partial knee replacement. When people have more severe arthritis or deformity of the knee joint, a partial knee replacement is unlikely to be successful.

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. The reason for this is the result of multiple issues.

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

Partial knee replacements typically will last a decade or two. Some studies have shown good results with these implants lasting well into the second decade with the majority of implanted partial knee replacements still functioning well.

Some people choose to have a partial knee replacement change to a full knee replacement. Recent studies have shown reasonably good results when people require 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. The benefit of partial knee replacement includes 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.

Was this page helpful?
Article Sources