What is Unicompartmental Knee Replacement?

If your knee has been damaged by arthritis and the pain, instability or stiffness are having serious effects on your daily activities, surgery is often the next consideration you need to make. There are various options that your doctor will consider, one of which might be unicompartmental knee replacement. Also known as a partial knee replacement, unicompartmental knee replacement is suitable for some patients where part of the knee is affected by arthritis.

To further understand this type of surgery and the benefits that may come from having a partial knee replacement, consider the following information and discuss your eligibility with your doctor.

Knee Arthritis 

Your knee is made up of three compartments:

  • Medial (the inner compartment of your knee)
  • Lateral (the outer compartment of your knee)
  • Patellofemoral (your kneecap)

Unicapmartmental pic

Any or all three of these compartments can be affected by arthritis. This involves the eventual wearing away of the normal cartilage covering the surface of a joint, and the bone underneath becoming damaged. This of course, can lead to pain, stiffness and an inability to participate in normal activities.

If only part of the knee is damage, an unicompartmental knee replacement could be a viable option.

Unicompartmental Knee Replacement 

Unicompartmental knee replacement or partial knee replacement can be performed when arthritis is confined to only one compartment of the knee. During this surgery, the damaged compartment of the knee is replaced with a prosthesis. The healthy parts of the knee including bone, cartilage and ligaments remain untouched.

Inicompartmental 3 pic

Total v Unicompartmental knee replacement


Advantages of Unicompartmental Knee Replacement 

Unlike total knee replacement surgery, unicompartmental knee replacement is less invasive and preserves all healthy parts of the knee including ligaments (these are removed in total replacements). With a smaller incision, shorter operation time, and less time spent in hospital; recovery and rehabilitation are often much quicker. Many patients also report that their knee feels more ‘natural’ compared to a total knee replacement.

If you are a suitable candidate for unicompartmental knee replacement, you can expect excellent long-term results with improved functionality and reduced pain.

knee replacement CTA

Candidates for Unicompartmental Knee Replacement 

If your arthritis has advanced and non-surgical treatments including medication, injections, physiotherapy and activity modifications are no longer relieving your symptoms, your doctor may recommend knee replacement surgery. However, an unicompartmental knee replacement is not suitable for all arthritis patients.

To determine if you are a suitable candidate for an unicompartmental knee replacement, your doctor will assess a range of factors including (but not limited to):

  • Where your arthritis is located
  • The severity of your symptoms
  • How much wear and tear your knee joint will be subject to over time
  • The degree of knee deformity
  • The stiffness and instability of your knee

In general, surgery of all kinds is a personal decision and will often depend on your daily activity demands, social life, work and family commitments.

When assessing any surgical option, it is always a good idea to understand all options and how they can affect you personally. An unicompartmental knee replacement might be the relief you are looking for, but it is important to obtain the best advice before leaping into anything.

Dr Stuart MacKenzie is one of the top Orthopaedic Surgeons in Newcastle and the Hunter Valley. He has created a compressive e-guide called “Your complete guide to knee replacements” that will help you understand all options available when it comes to knee surgery.

13 Jan 2020

Published by Stuart MacKenzie

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