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

A partial (unicompartmental) knee replacement resurfaces only the worn compartment of the knee — usually the inner side — while keeping all the healthy bone, cartilage, and ligaments, including the ACL. A total knee replacement resurfaces the entire joint. For the right candidate, a partial means a smaller operation, faster recovery, and a knee that feels more natural.

Am I a candidate for partial knee replacement?

Roughly one in four knee-arthritis patients is a candidate: arthritis confined to one compartment, intact ligaments, and reasonable alignment. The honest answer comes from standing X-rays and an exam — and at Sterling Ridge, robotic planning maps your knee precisely enough to confirm whether a partial will hold up for you.

How long does a partial knee replacement last?

Modern partial knee replacements commonly last 15 or more years. When arthritis later spreads to other compartments, a partial can be converted to a total knee replacement — a well-understood pathway rather than a dead end.

Partial Knee Replacement in The Woodlands, TX

Why replace the whole knee if only one part is worn?

About one in four knee-arthritis patients has damage confined to a single compartment. For them, resurfacing just that part — and keeping every healthy ligament, including the ACL — means a smaller operation, a faster comeback, and a knee that still feels like a knee.

The honest version

A partial knee replacement resurfaces only the arthritic compartment of your knee — typically the inner (medial) side — while preserving your ligaments and the rest of the joint. Done for the right knee, it recovers faster than a total and feels more natural. Done for the wrong knee, it fails early. Which is why the decision here starts with standing X-rays and robotic-precision planning, not enthusiasm.

Partial vs. total — the real trade-offs

Partial: smaller incision, less bone removed, ACL preserved, commonly home the same day from our surgery center, quicker return to driving and golf. The catch: arthritis can later spread to the untouched compartments.
Total: the definitive answer when more than one compartment is worn — and the right first choice for most knees that reach us late. The full knee replacement page covers it honestly.
The conversion path: if a partial's remaining compartments wear out years later, it converts to a total — a known, planned-for pathway.

Why robotic planning matters most here

Partial knees live or die on precision — the implant must match your anatomy and alignment within tight tolerances. Our Mako robotic system builds a 3D plan from a CT scan and holds your surgeon to the millimeter. It's the difference between a partial that lasts and one that gets revised.

Is your knee a candidate?

The screening questions are simple: Is the pain localized to one side of the knee? Are your ligaments intact? Is your alignment reasonable? Standing X-rays answer most of it, and about a third of the people who ask us hear "you're better served by something else" — including, sometimes, waiting.

The surgeons who do this here

Board-certified, fellowship-trained, and in the office every week — read their story, then decide.

Brian Flowers, MD, FAAOSHip & Knee Replacement

Rohan Gheewala, MDHip & Knee Replacement · Revision

Paul Chin, MD, PhD, FAAOSRobotic Knee Replacement

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Medically reviewed by Keith W.V. Johnson, MD, FAAOS · Updated September 28, 2026