Partial Knee Replacement

Partial Knee Replacement (also known as unicompartmental knee replacement) is a surgical procedure that replaces only the damaged part of the knee joint, rather than the entire knee. It’s less invasive than a total knee replacement and is an excellent option for patients with arthritis limited to one compartment of the knee.

🦵 What Is Partial Knee Replacement?

The knee is divided into three compartments:

Medial (inner part)

Lateral (outer part)

Patellofemoral (kneecap area)

In a partial knee replacement, only the affected compartment is resurfaced with metal and plastic implants. The rest of the knee—including ligaments and cartilage—is left intact.

✅ Who Is a Candidate?

Ideal candidates have:

Osteoarthritis confined to one compartment

Good range of motion

Stable ligaments, especially the ACL

Lower body weight or less physically demanding lifestyle (though this is changing with newer techniques)

Not recommended if:

Arthritis affects multiple compartments

Severe knee deformity or instability

Inflammatory arthritis (like rheumatoid arthritis)

⚙️ Procedure Overview

Anesthesia: Spinal or general

Incision: Small (3–6 inches)

Resurfacing: Damaged bone and cartilage are removed from one compartment

Implants: A metal cap is placed on the femur, and a plastic spacer or cap on the tibia

🕒 Surgery time: ~1–2 hours

🏥 Hospital stay: Often same-day or 1 night

⏱️ Recovery Timeline

Activity Timeline

Walking with assistance 1–2 days

Return to work (desk job) 2–3 weeks

Resume driving 2–4 weeks

Physical therapy 6–8 weeks

Full recovery 3–4 months

Recovery is generally faster and less painful than after total knee replacement.

🩺 Advantages Over Total Knee Replacement

Smaller incision and less tissue trauma

Retains more of your natural knee

Quicker recovery and less pain

Feels more “natural” during movement

Less blood loss

Lower risk of complications like infection or blood clots

⚠️ Potential Risks and Complications

Blood clots

Infection

Implant loosening or wear

Continued pain (if arthritis progresses in other parts of the knee)

Need for revision surgery (conversion to total knee replacement later)

🔁 Longevity of Implants

Modern partial knee implants last 10–15+ years in most patients.

Some may require revision if arthritis spreads or the implant fails.