Zachary P. Berliner, MD/Robotic Knee Replacement
Knee Replacement
Robotic-arm assisted knee replacement
The surgeon still does the surgery. The robotic arm makes the plan harder to deviate from. Here is what that actually means for your knee, and what the first year looks like.
How the robotic arm is used
The surgeon performs the operation. Every cut and every decision about implant size and position is made by the surgeon. The robotic arm does not operate independently.
The arm holds the cutting tool inside a boundary the surgeon defines. When the plan sets a stopping point, the arm will not pass it. This removes the millimeter-scale variation of freehand cutting.
How the plan gets built
Before or during surgery, your knee is mapped in three dimensions. The surgeon can see your own alignment, the shape of your bone, and how your ligaments behave as the knee bends. The implant plan is built from your knee rather than from an average knee.
During surgery, that plan can be adjusted in real time. If the ligaments balance better with the implant rotated slightly, the surgeon changes it before removing any bone.
What the evidence shows. Robotic assistance improves the accuracy of implant placement. Whether that accuracy changes how a knee feels at ten to fifteen years is still under study. Excellent results are achieved without robotic assistance, and surgeon volume remains the stronger predictor of outcome.
Total and partial knee replacement
The knee has three compartments, and arthritis does not always involve all three.
- Total knee replacement resurfaces the whole joint. It is the right answer when wear is widespread or the knee is badly deformed.
- Partial knee replacement resurfaces only the worn compartment and leaves your healthy bone and ligaments in place. Recovery is usually quicker and many patients say the knee feels more like their own.
Not everyone qualifies for a partial. It depends on where the arthritis is, how stable your ligaments are, and how the knee straightens. This gets decided from your imaging and exam, not from preference.
Recovery timeline
- Day one You stand and walk with a walker, usually the same day. Bending the knee starts immediately.
- Week one to three The work is regaining bend and full straightening. This part is uncomfortable and it is the part that matters most. Most people are off the walker in two to three weeks.
- Week four to six Desk work is realistic. Walking distance builds steadily. Driving usually returns in this window.
- Month three The biggest gains are behind you. Most daily activity feels normal.
- Month twelve Swelling and stiffness keep improving quietly for a full year. Judge the result at a year, not at a month.
What knee replacement does not treat
Knee replacement treats arthritis pain. It does not restore a deep squat for most patients, and it does not address pain referred from the lumbar spine or the hip. Identifying the true source of the pain is part of the first visit.
Common Questions
Knee replacement questions
Does a robot perform the knee replacement?
No. The surgeon performs the operation and makes every decision. The robotic arm holds the cutting tool inside a boundary the surgeon has set, so it will not move outside the plan. Think of it as a very precise guide, not an independent operator.
Is robotic better than traditional knee replacement?
It is more precise at placing the implant, and that is well established. Whether that precision makes your knee feel better ten years later is still being studied. Honest answer: it is a good tool, and the surgeon using it matters more than the tool itself.
What is the difference between a partial and a total knee replacement?
A knee has three compartments. If only one is worn out, a partial replacement resurfaces just that part and leaves your healthy ligaments and bone alone. Recovery is usually faster and the knee often feels more natural. Not everyone is a candidate.
How long is recovery?
You will walk the same day or the next. Most people are off a walker within two to three weeks and back to desk work in four to six. The knee keeps improving for a full year, with the biggest gains in the first three months.
Is a knee replacement more painful than a hip replacement?
Usually yes, in the early weeks. Knees need steady work to regain bend and straightening, and that work is uncomfortable. The pain is manageable and temporary, but knee recovery asks more of you than hip recovery does.
Will I be able to kneel afterward?
Many people can, but it often feels odd or numb rather than painful, and some never find it comfortable. Kneeling will not damage the implant. If kneeling matters for your work or faith, say so before surgery.
Also Worth Reading