Partial (Unicondylar) Knee Replacement: Is It Right for You?
Medically reviewed by Dr. Mohsin Merchant, Orthopaedic Surgeon | Pain Cure Ortho & Rehab Clinic, Mazgaon, Mumbai |
Knee arthritis does not always affect the whole knee. When the wear is limited to one part of the joint, a partial knee replacement, also called a unicondylar knee replacement, is sometimes an option. This guide explains what it is, who it may suit and how it compares with a total knee replacement, so you can ask better questions at your consultation.
How the knee wears
The knee has three main compartments: the inner (medial) side, the outer (lateral) side, and the joint behind the kneecap. In many people with osteoarthritis, the cartilage wears mainly on the inner side first. If the other compartments are still healthy, replacing only the damaged part is one way to treat the problem.
What is a unicondylar knee replacement?
In this operation the surgeon replaces only the worn compartment with a metal and plastic implant, and keeps the rest of the knee, including the healthy cartilage and the ligaments. A total knee replacement, by comparison, resurfaces all the compartments.
| Partial (unicondylar) | Total | |
|---|---|---|
| Part replaced | One compartment, usually the inner side | The whole joint surface |
| Suits when | Arthritis is limited to one compartment and the ligaments are healthy | Arthritis affects more than one compartment, or there is deformity or ligament damage |
| Bone removed | Less | More |
| Recovery | Often quicker, but it varies from person to person | Usually longer |
| If arthritis spreads | A further operation may be needed later | Not applicable to the same extent |
Who may be suitable
- Pain mainly on one side of the knee, usually the inner side
- Arthritis limited to one compartment on X-ray or MRI
- A stable knee with a healthy anterior cruciate ligament (ACL)
- Limited deformity and a reasonable range of movement
- Pain that has not improved enough with non-operative treatment
Who may not be suitable
- Arthritis in more than one compartment of the knee
- Inflammatory arthritis such as rheumatoid arthritis
- Significant deformity, stiffness or loose ligaments
- Marked pain at the front of the knee, behind the kneecap
Suitability is decided by examination and imaging, not by age alone, and the final decision is made together with your surgeon.
Try non-operative care first
Knee replacement is not the first step. Weight management, physiotherapy to strengthen the thigh muscles, changes in activity, walking aids and medicines are usually tried first. At Pain Cure Ortho & Rehab Clinic, non-operative care for knee pain includes physiotherapy and the other therapeutic modalities listed on the Knee Treatment page. Surgery is considered only when assessment shows it is appropriate.
Surgery and recovery
The operation is done under anaesthesia and usually needs a short hospital stay. Some surgeons use robotic assistance to plan the operation and position the implant. Most people start walking with support within a day or two, and physiotherapy begins early and continues for several weeks. Strength and confidence in the knee can keep improving for some months. Recovery varies with age, fitness and the operation done, and structured rehabilitation after surgery plays a large part in the result.
Risks to discuss with your surgeon
Every operation has risks. For knee replacement they include infection, blood clots, stiffness, and wear or loosening of the implant over time, which can mean further surgery. Your surgeon will explain how these apply to you.
Frequently asked questions
Is partial knee replacement better than total knee replacement?
Neither is better for everyone. Partial replacement suits a smaller group of people whose arthritis is limited to one compartment. Total replacement is advised when more of the joint is affected.
How long does a partial knee replacement last?
Many implants last ten years or longer, but this depends on the implant, your weight and your activity. Your surgeon can tell you what to expect in your case.
Is it painful after surgery?
Pain is expected in the first days and is managed with medicines. Most people find it eases steadily as rehabilitation progresses.
When can I return to normal activities?
Walking and light daily activity usually resume within weeks. Driving and other activities depend on your surgeon's advice and your progress.
Book a knee consultation in Mazgaon
If any of this sounds familiar, you can book a consultation at Pain Cure Ortho & Rehab Clinic, 42/44 Patra Chawl New Compound, Love Lane, Opp. Sahakari Bhandar, Mazgaon, Mumbai 400010. The clinic is open Monday to Saturday, 10:00 AM to 10:00 PM, and closed on Sunday. Call or WhatsApp +91 79778 68264, or use the consultation form.
This article is for general education and does not replace a consultation. If you have symptoms, please see a qualified doctor.