James Lairmore, MD

Orthopaedic Surgery

620-669-2554

Benefits of Unicompartmental Replacement Over Total Knee Replacement

Unicompartmental knee replacement is intended to preserve the healthy knee structures, and is intended to restore normal knee motion and function.  Unlike other components, the Oxford™ Meniscal Unicompartmental Knee has a fully mobile bearing, which limits the forces and stresses seen by the implant that may often lead to loosening.  The Oxford™ Meniscal Unicompartmental Knee is currently the only fully mobile bearing unicompartmental knee system in the United States.  

Reconstruction

The traditional approach to knee reconstruction has been a total knee replacement, which replaces all three compartments of the knee.  However, total knee replacement may not be necessary for every patient.  Osteoarthritis often develops in only one compartment of the knee, while the other two compartments remain relatively healthy.  Patients who have osteoarthritis in only one compartment may not need a total joint replacement.  They may be candidates for a unicompartmental knee.

Minimally Invasive Microplasty™ Technique for Rapid Recovery

With the Oxford™ minimally invasive technique, it is not necessary for your surgeon to make a large incision which would surgically expose healthy parts of the knee.  With use of the Oxford™ proprietary instruments, the operation may be performed through a small incision with great precision.  The system allows accurate balancing of the knee through this small incision avoiding disruption of the thigh muscles (quadriceps), which also contributes to a quicker recovery.

In addition to a less invasive surgery and a smaller incision, the procedure also removes less tissue from both the tibia and femur because only the damaged cartilage is removed.

Most patients walk on their surgical knee the same day as surgery and can possibly be discharged within 24 hours.  Some patients may need to use a walker or a cane for the first week.  Your condition will determine when you will be discharged.

Frequently Asked Questions

Who can benefit from unicondylar reconstruction?

Adults who show one or more of these symptoms may benefit from this procedure:

• Pain while standing

• Pain while walking a short distance

• Pain changing position, such as sitting to standing

• Persistent knee swelling

• Giving out or locking of the knee

• Failure of the knee to respond to medication

What is the difference between a unicondylar knee replacement and a total knee replacement?

Only part of the joint surface is replaced with a unicondylar knee replacement.  A total knee replacement involves resurfacing the entire knee.

Why would I have a unicondylar knee replacement rather than a total knee replacement?

There may be several reasons.  A unicondylar knee replacement is typically used for patients who have osteoarthritis in limited parts of their knee.  If you have osteoarthritis in more than one area of your knee, a total knee replacement is usually recommended.  Of course, there may be other reasons for having a unicondylar knee replacement.

Are there different types of unicondylar knee replacement?

Yes.  There are many different designs on the market.  The most significant difference is whether the polyethylene (plastic) lining of the new knee is free to move or not.  A moving plastic bearing (as in the Oxford™) is known as a mobile bearing type.  When the plastic cannot move, the replacement is a fixed bearing type.

Does a unicondylar knee replacement last longer than a total knee replacement?

Not necessarily.  All implants have a limited life expectancy depending on an individual's age, weight, activity level and medical condition.  Research has shown that the newer types of unicondylar knee replacements, particularly those with moveable plastic bearings like the Oxford™ Unicondylar Knee, have exceptionally low wear rates, potentially giving them even longer life expectancies.  You can, of course, go on to have a total knee replacement after a previous unicondylar knee replacement, should it become necessary.

What activities can I expect to do after the surgery?

The amount of activity you will be able to perform will depend on several variables, including what activities you were able to perform before the operation.  It will also depend on how much your surgeon allows.

What can I expect during rehabilitation?

You should follow the exercise program advised by your doctor.  This may include visiting a physical therapist.  Beside specific exercises to strengthen your knee joint, they will help you learn the best way to perform every day activities such as climbing stairs and rising from a chair.

What can I expect from the device?

The Oxford™ Meniscal Unicompartmental Knee is intended to reduce pain and restore function to your knee.  As with any artificial joint, this prosthesis will not restore your knee to a normal, undiseased joint.