Is Unicompartmental Knee Replacement Right for You?
Knee arthritis can significantly affect your quality of life, turning simple activities like walking or climbing stairs into painful challenges. For many, the thought of knee surgery brings to mind a total knee replacement. However, there is another highly effective, less invasive option that may be suitable for your specific condition: the unicompartmental knee replacement.
This procedure, also known as a partial knee replacement, is designed to relieve pain while preserving as much of your natural knee as possible. This guide will walk you through what unicompartmental knee replacement involves, its benefits, who makes a good candidate, and what to expect during recovery.
What is Unicompartmental Knee Replacement?
Your knee joint is divided into three main compartments: the medial (inner) compartment, the lateral (outer) compartment, and the patellofemoral compartment (behind the kneecap). In some people with osteoarthritis, the damage is confined to just one of these compartments, most commonly the medial one.
A unicompartmental knee replacement is a surgical procedure that resurfaces only the damaged compartment of the knee, leaving the healthy bone and cartilage in the rest of the joint untouched. This is the main difference between a partial and a total knee replacement, where all three compartments are replaced with artificial components. By targeting only the affected area, a partial knee replacement offers a more conservative approach to treating knee arthritis.
The Benefits of a Partial Knee Replacement
Choosing a unicompartmental knee replacement can offer several advantages over a total knee replacement, provided you are a suitable candidate. The benefits often include:
Less Invasive Surgery
The procedure typically involves a smaller incision and less disruption to the surrounding bone and soft tissues. This means less surgical trauma, resulting in a quicker and more comfortable recovery. While the transfusion rate in total knee replacement is low (<1%), historically, unicompartmental knee replacement has an even lower transfusion rate.
Faster Recovery and Rehabilitation
Patients who undergo a partial knee replacement often experience a faster recovery. Many can walk with minimal assistance soon after surgery and return to their daily activities more quickly. Hospital stays are generally shorter, and the rehabilitation process is often less intensive compared to a total knee replacement.
More Natural Knee Movement
Because two-thirds of your knee remains untouched, the joint often feels more ‘natural’ after a partial knee replacement. The ligaments that help stabilise your knee are preserved, which helps maintain more normal joint kinematics and can result in a better range of motion.
A Bone-Preserving and Soft Tissue Sparing Option
Since only a small portion of the bone is removed, a unicompartmental knee replacement is considered a bone-preserving procedure. This can be beneficial for younger, more active patients, as it leaves more bone if conversion to a total knee replacement becomes necessary later in life.
Who is a Good Candidate for Partial Knee Replacement?
A unicompartmental knee replacement is an excellent solution, but it may not be suitable for everyone. Studies show that only 5% of patients requiring joint replacement surgery are candidates for unicompartmental replacement surgery.
A thorough evaluation by an experienced orthopaedic surgeon is essential to determine if this procedure is the right choice for you.
Generally, ideal candidates for partial knee replacement have the following characteristics:
- Localised osteoarthritis – The arthritis is confined to a single compartment of the knee.
- Minimal deformity and bone loss
- Intact Ligaments – The ligaments in the knee, particularly the anterior cruciate ligament (ACL), are stable and functional.
- Good Range of Motion – The knee still has a reasonable degree of flexibility.
- Not Severely Overweight – While not a strict requirement, maintaining a healthy weight helps reduce stress on the implant and the rest of the knee.
- No Inflammatory Arthritis – Patients with conditions like rheumatoid arthritis, which affects the entire joint, are typically not candidates.
Patients seeking knee surgery in Sydney have access to advanced diagnostic tools to pinpoint the exact location and extent of their arthritis, helping to confirm their suitability for this less invasive knee joint replacement surgery.
The Surgical Procedure: A High-Level Overview
During a unicompartmental knee replacement, your surgeon makes an incision at the front of your knee. They then carefully remove the damaged cartilage and bone from the affected compartment. The surfaces are precisely shaped to fit the metal and plastic implants, which are then secured in place.
These new surfaces restore smooth, pain-free movement to that part of the knee. The procedure is performed with meticulous attention to detail to ensure optimal alignment and function.
Recovery and Life After Surgery
Your recovery journey begins as soon as the surgery is complete. You will be encouraged to get up and move around shortly after the procedure, with the help of a physiotherapist. A personalised rehabilitation program is a crucial part of your recovery, designed to restore strength, flexibility, and function to your knee.
The recovery timeline for a partial knee replacement is typically faster than that of a total replacement. Most patients can expect to:
- Walk with a walker or crutches for a short period.
- Return to driving within a few weeks.
- Resume most daily activities within six weeks.
- Get back to low-impact sports and recreational activities within a few months.
- Following your surgeon’s and physiotherapist’s advice is key to achieving the best possible outcome.
Understanding the Risks
Like any surgical procedure, a unicompartmental knee replacement has potential risks. These can include infection, blood clots, stiffness, and ongoing pain. The arthritis could also progress in the other compartments of the knee over time, potentially requiring further surgery. However, the complication rates for this procedure are low, and many patients enjoy pain relief and improved function for many years. Discussing these risks with your orthopaedic surgeon will help you make a fully informed decision.
Is This the Right Path for You?
Unicompartmental knee replacement offers a powerful solution for individuals with single-compartment knee arthritis, providing significant pain relief and a faster return to an active lifestyle. Preserving healthy bone and tissue allows for more natural knee function and serves as an effective alternative to total knee replacement for the right patient.
If you are experiencing knee pain and considering your options, the first step is to consult a professional medical advisor. A consultation with orthopaedic surgeon Dr Dan Cohen can provide a clear diagnosis and help you understand whether a partial knee replacement or another treatment is the best path forward for your health.