You’ve done the physical therapy. You’ve had the injection, maybe two. You’ve swapped running for the bike and started planning errands around how your knee feels that day. When knee arthritis keeps winning, the conversation usually turns to replacement, and one of the first questions patients ask is whether they need the whole knee replaced or just part of it.
The honest answer depends on where the damage is. Here’s how that decision usually gets made.
Your knee has three “rooms”
It helps to think of the knee as three compartments: the inner side (medial), the outer side (lateral), and the area behind the kneecap (patellofemoral). Arthritis doesn’t always wear down all three evenly. Some people have badly worn cartilage on the inner side and fairly healthy cartilage everywhere else. Others have arthritis spread across the whole joint.
That pattern is what separates the two operations.
- Partial knee replacement (also called a unicompartmental or “uni” knee) resurfaces only the worn compartment and leaves the healthy cartilage and ligaments in place.
- Total knee replacement resurfaces all three compartments, replacing the worn ends of the thigh bone and shin bone and, often, the back of the kneecap.
Who tends to be a good fit for a partial knee
A partial knee is usually considered when:
- Arthritis is limited mostly to one compartment on X-ray and exam
- The main knee ligaments, including the ACL, are working well
- The knee still bends and straightens reasonably well
- There isn’t a large bow-legged or knock-kneed deformity
- Pain is clearly located on one side of the knee rather than all over
Because less of the knee is changed, many patients describe a partial knee as feeling more like their “own” knee, and recovery is often quicker in the early weeks. The tradeoff is that the untouched compartments can still develop arthritis down the road, and some partial knees are later converted to a total.
When a total knee is the better choice
A total knee replacement is usually the better path when:
- Arthritis involves two or three compartments
- There is significant deformity or stiffness
- Ligaments are worn out or unstable
- The arthritis is inflammatory, such as rheumatoid arthritis, which tends to affect the whole joint
Total knee replacement is one of the most established operations in orthopedics. For the right patient, it’s a reliable way to treat arthritis that has spread through the knee, and it removes the worry of arthritis progressing in another part of the same joint.
How we decide together
At Movement Orthopedics, this decision starts with standing X-rays, a hands-on exam of your ligaments and motion, and a real conversation about where it hurts and what you want to get back to. Sometimes advanced imaging helps clarify the picture. Dr. Jeffrey J. Carroll, DO, who specializes in hip and knee reconstruction, offers both partial and total knee replacement, including robotic-assisted options when they fit the case.
Not everyone with knee arthritis needs surgery yet. If you haven’t tried a structured course of therapy, activity changes, bracing, or injections, that’s often the first step, and our team can walk you through it.
What recovery usually looks like
Recovery varies from person to person, so treat these as general patterns, not promises:
- Partial knee: Many patients walk the same day or next day with support and move through early milestones a bit faster. Physical therapy still matters.
- Total knee: Walking also starts early, but the knee often takes longer to settle down. Most patients work through several weeks of focused physical therapy, with continued improvement over the following months.
With either surgery, your effort in therapy is one of the biggest factors in how the knee feels at the end. Our physical therapy team works alongside the surgical team, which makes it easier to stay on track.
When to come in
If knee pain is limiting your walking, your sleep, or the activities you care about, and the usual treatments aren’t holding it anymore, it’s worth an evaluation. Call (586) 436-3785 to schedule with Dr. Carroll at our Clinton Township office (43475 Dalcoma Dr.) or our Lenox office (36555 26 Mile Road, Suite 2400). For a new injury, walk-in care is available at our Clinton Township office. Walk-in hours change week to week, so call ahead or check our walk-in page for current times.
This article is general information, not medical advice. Every knee is different, so talk with a physician about your own situation before deciding on treatment.