— Knee · one-compartment · Mako-assisted
Replace only
what's worn out.
When arthritis is confined to a single compartment of the knee, there’s no reason to replace the whole joint. A partial knee replacement resurfaces just the damaged side — preserving bone, ligaments, and the part of your knee that still works perfectly well.
One side
Resurfaced
Only the damaged compartment is replaced — the rest of the knee stays yours.
Bone & ligaments
Preserved
Both cruciate ligaments stay intact, along with most of your native bone.
Smaller
Incision
A smaller incision than a total knee, with less soft-tissue disruption.
More natural
Feel
Most patients describe a partial knee as feeling closer to a “normal” knee.
See the procedure.
A short animation of a Mako partial knee replacement, showing how only the damaged compartment is resurfaced — and why preserving the rest of the knee matters for how the joint feels and functions afterward.
— Animation
Mako Partial Knee Replacement
Video courtesy of Stryker
What "partial"
means here.
The knee has three compartments: medial (inside), lateral (outside), and patellofemoral (under the kneecap). Arthritis sometimes affects all three — but more often, it starts in just one. A partial replacement resurfaces only the worn compartment and leaves the rest alone.
For decades, total knee replacement was the default answer to knee arthritis — even when only one compartment was actually worn out. The problem is that a total knee removes both cruciate ligaments and resurfaces healthy cartilage, which changes how the knee moves and how it feels under the patient.
A partial knee replacement is more conservative. Both cruciate ligaments stay intact. The unworn compartments stay untouched. The implant resurfaces only the area that’s actually arthritic. Patients consistently report that a partial knee feels more like a natural knee than a total knee does — because mechanically, it nearly is.
Not every knee is a candidate. The arthritis has to be confined to one compartment, the ligaments need to be intact, and a few other anatomical factors have to line up. The right way to know is an exam plus X-rays — and sometimes an MRI.
— Why a partial is worth considering
01
Feels more natural
Native ligaments and most native cartilage stay in place.
02
Smaller incision
Less soft-tissue disruption means faster early recovery.
03
Preserves future options
If conversion to a total is ever needed years down the road, we perform it robotically — the same Mako precision that placed the partial guides the conversion.
04
Faster early recovery
Most patients walk the same day and progress faster in PT.
Who's a candidate?
Partial knee replacement is one of the most underused good operations in orthopedic surgery — partly because not every surgeon is comfortable with it, and partly because patient selection matters more here than in a total knee. The criteria below are the starting point for the conversation.
01
Arthritis in one compartment
X-rays show wear isolated to the medial or lateral side, with the other compartments preserved. Most commonly the medial side.
02
Intact ligaments
A functional ACL is essential. The integrity of the collateral ligaments matters too — they’re what make partial knee mechanics work.
03
Stable, correctable alignment
Mild varus or valgus deformity is fine if it corrects passively. Severe fixed deformity points back toward a total knee.
04
Adequate range of motion
A knee that’s already stiff or contracted is harder to make work as a partial. We assess this on exam.
05
Inflammatory arthritis ruled out
Rheumatoid arthritis and other inflammatory conditions affect all compartments — a partial knee isn’t the right answer.
06
Realistic expectations
A partial knee is for relief of single-compartment pain. If the other compartments deteriorate over years, conversion to a total may eventually be appropriate.
Why Mako matters
even more.for a
partial.
Partial knee replacement is technically demanding. The implant has to fit precisely against the preserved cartilage on either side — there’s no margin for the kind of small alignment error that a total knee can absorb. Robotic precision turns out to matter more here, not less.
— Technology
Mako for Partial Knee Replacement
Video courtesy of Stryker
More on
the procedure.
A closer look at what’s involved in a partial knee replacement, narrated end-to-end.
— Overview
Partial Knee Replacement
Video courtesy of Stryker
Recovery,
week by week.
Partial knee recovery is typically faster than total knee — less bone work, less soft-tissue disruption, and a knee that already feels more like itself from day one.
DAY 0
Surgery & walking
Procedure takes about 60–75 minutes. Most patients walk within hours of waking up.
DAY 1
Home or one night
A majority of appropriate-candidate partial knee patients go home the same day as surgery.
WEEK 1–2
Off the walker
Most patients move from walker to cane to nothing in this window. Range of motion comes back faster than a total knee.
WEEK 3–6
Daily life resumes
Desk work, walking distances, and \u2014 depending on side and transmission \u2014 driving returns (typically 2\u20133 weeks for a left knee in an automatic, 4\u20136 weeks for a right knee). Many patients describe the knee already feeling like their own.
WEEK 6–12
Activity & strength
Hiking, biking, golf, swimming. Strength continues to build through 3 months and beyond.
— LONG TERM
A knee that feels like yours
The signature outcome of a well-done partial knee: patients often forget which side was operated on. Modern partial implants are designed for 15–20+ years of use.
— LONG TERM
A knee that feels like yours
The signature outcome of a well-done partial knee: patients often forget which side was operated on. Modern partial implants are designed for 15–20+ years of use.
Frequently asked
questions.
The questions patients ask most often before scheduling a partial knee replacement.
How do I know if I'm a partial knee candidate?
It comes down to exam findings and imaging. X-rays show whether the arthritis is in one compartment or several. Exam tells us whether the ligaments are intact and the alignment correctable. Sometimes we’ll get an MRI to confirm. We make the call at your evaluation.
If I have a partial, will I need a total later?
No. The Mako robotic arm doesn’t operate autonomously. Every motion is controlled by the surgeon. The system enforces the surgical plan — it prevents the kind of small alignment errors that can compound over years — but the operation itself is still surgeon-led from start to finish.
Why doesn't every surgeon offer partial knee?
No. The Mako robotic arm doesn’t operate autonomously. Every motion is controlled by the surgeon. The system enforces the surgical plan — it prevents the kind of small alignment errors that can compound over years — but the operation itself is still surgeon-led from start to finish.
How is the recovery different from a total knee?
No. The Mako robotic arm doesn’t operate autonomously. Every motion is controlled by the surgeon. The system enforces the surgical plan — it prevents the kind of small alignment errors that can compound over years — but the operation itself is still surgeon-led from start to finish.
Will the knee feel different from a total knee?
No. The Mako robotic arm doesn’t operate autonomously. Every motion is controlled by the surgeon. The system enforces the surgical plan — it prevents the kind of small alignment errors that can compound over years — but the operation itself is still surgeon-led from start to finish.
What activities can I do afterward?
No. The Mako robotic arm doesn’t operate autonomously. Every motion is controlled by the surgeon. The system enforces the surgical plan — it prevents the kind of small alignment errors that can compound over years — but the operation itself is still surgeon-led from start to finish.
— What patients say
From partial knee
patients like you.
— Fellowship-trained · UCLA · Allegheny General
Dr. Omar Kadri.
Fellowship-trained orthopedic surgeon specializing in muscle-sparing hip replacement, robotic-assisted joint reconstruction, and regenerative orthopedics. Trained at UCLA School of Medicine, Henry Ford Health System, and Allegheny General Hospital. Practicing in Riverside and Corona.
Find out if a partial
is right for you.
Start with an evaluation visit — exam, X-ray review, and a straight conversation about whether partial or total knee replacement fits your knee.