Knee Replacement Medically reviewed by Thomas D. Ferro, M.D. in Newport Beach

There's a strong chance. In the largest pooled analysis of national joint registry data, about 82% of total knee replacements and 70% of partial knee replacements were still in service 25 years after surgery.[5] Accurate implant positioning is one of the factors that supports results like these.

Yes. Component position and balance are among the factors a surgical team can influence that affect how long a knee replacement lasts.[2] That's why NanoKnee concentrates on them, using detailed 3D modeling, biomedical engineering and FDA-cleared implants to plan where your implant sits and how it's aligned for your anatomy.

Good candidates have been advised to get a knee replacement and want to recover at home, maintain an active lifestyle, and have an implant planned specifically for their knee. NanoKnee was developed for active patients aiming for top-level function after surgery, whether they're younger adults or older adults in good health. Your surgeon will confirm candidacy at your consultation after looking at your imaging, health, history and goals.

It's strong. Knee replacement is one of the most widely performed and extensively studied procedures in the U.S., with more than 4.4 million hip and knee replacements recorded by the American Joint Replacement Registry since 2012.[6] Serious complications are rare, and certain risks can be lowered through decisions made before surgery.

Anesthesia is one of those decisions. A national analysis of more than 380,000 joint replacements associated spinal (neuraxial) anesthesia with lower 30-day mortality and fewer in-hospital complications than general anesthesia.[7] NanoKnee procedures are performed by board-certified orthopedic surgeons using spinal anesthesia with sedation.

No. Standard mechanical alignment puts every knee at the same neutral target, yet a substantial share of adults naturally have knees that aren't in “neutral” alignment.[10] NanoKnee uses restricted inverse kinematic alignment (iKA) instead, a personalized approach that restores your natural tibial joint line and alignment within safe limits. In a matched series, patients aligned this way reported higher satisfaction and better Oxford Knee Scores at one year than patients aligned to an adjusted mechanical target.[11] Your plan is developed from your CT scan and reviewed by your surgeon before surgery.

Patients whose arthritis is limited to one or two areas of the knee. NanoKnee surgeons perform partial (unicompartmental) and bicompartmental knee replacement, which resurface only the damaged one-third or two-thirds of the joint and spare your ligaments and healthy bone. A randomized trial of 528 patients with arthritis in the inner compartment found partial knee replacement achieved equivalent improvement with fewer complications.[12][13] Your NanoKnee surgeon will talk with you about whether it suits your anatomy and knee condition.

If you're a suitable candidate, no. NanoKnee's advanced 3D modeling lets our surgeons use a quadriceps-sparing approach that reaches the joint without cutting the quadriceps tendon, and randomized trials show it reduces pain in the first days after surgery.[8] For arthritis limited to one compartment, a Nano partial knee replacement is the least invasive option, removing the least bone and preserving your ligaments.[12] With a total knee replacement, the plan and approach matter more than the length of the incision.

Not usually. NanoKnee surgeons use spinal (regional) anesthesia with a local anesthetic block and “twilight” sedation, keeping you comfortable and unaware without general anesthesia. In a national analysis of more than 380,000 joint replacements, spinal anesthesia was linked to lower 30-day mortality and fewer complications than general anesthesia.[7] If your health makes general anesthesia the safer path, your team will recommend it.

Usually about two hours after surgery, since NanoKnee is performed on an outpatient basis. In a meta-analysis of 20 studies, appropriately selected outpatients had complication and readmission rates comparable to inpatients.[9] Your surgeon will confirm ahead of time that same-day discharge is a safe fit for you.

In about 90 minutes. Since your implant's size, position and alignment are already decided in your 3D plan, your surgeon has fewer decisions to make under time pressure during surgery.

Most NanoKnee patients are walking within 90 minutes of surgery and doing light activities during the first week. A typical progression:

• 7–14 days: normal daily routine
• 2–4 weeks: moderate activities
• 4–8 weeks: an active lifestyle

Your surgeon will adjust the timeline as you heal.

It's a structured program you complete at home under your surgeon's direction, rather than weeks of clinic visits. You'll start with walking, isometrics and stretching right away and work toward strengthening, biking, and activities like golf and hiking. The NanoKnee app makes it easy to track progress and contact your care team.

Most NanoKnee patients enjoy hiking, cycling, golf, tennis, running and skiing once they've recovered.

Most NanoKnee patients regain the flexibility they need for daily life and sports, and many recover motion arthritis had cost them. Your 3D plan balances your ligaments through the full range of motion, supporting a knee that bends and straightens fully. In our recovery-unit records, the median knee flexion right after surgery was 125° across 720 NanoKnee patients, with the middle half between 120° and 134°.

NanoKnee procedures use a cosmetic, plastic-surgical closure to help your scar heal as discreetly as possible. Most incisions heal in about two weeks, though you'll protect the area for the first two to three months.

Possible complications include infection, blood clots, stiffness, instability, implant loosening over time, and anesthesia-related risks. NanoKnee's surgical processes and proprietary 3D Blueprinting® address specific risks: spinal anesthesia is associated with fewer perioperative complications than general anesthesia,[7] and pre-operative 3D planning targets the position and balance problems that rank among the leading causes of early revision.[1] Expect a candid conversation with your surgeon about which of these apply most to you.

Over the months after surgery, most patients notice steadily improving function and fading arthritis pain. Some numbness around the incision and occasional clicking are common and rarely concerning. Your surgeon will monitor your recovery and address anything that isn't progressing normally.

Yes, for the planning. NanoKnee surgery is billed as a knee replacement, which Medicare and most commercial plans cover when medically necessary, but the pre-operative 3D planning and engineering aren't covered. Depending on your plan, that portion may cost up to $8,500. Our patient navigators will confirm your coverage and costs before you commit, and financing is available.

Not on its own. Many of the people who benefit most from a new knee are older adults whose arthritis has started keeping them from walks, travel or time with family. Eligibility comes down to how healthy you are for surgery, which is assessed in a comprehensive evaluation before every NanoKnee procedure. NanoKnee's standard spinal anesthesia is associated with fewer perioperative complications than general anesthesia.[7]

No. Your surgeon performs the operation, and no robot is used. AI plays a role only before surgery, helping our biomedical engineers turn your CT scan into a 3D model that your surgeon reviews and approves. NanoKnee's precision comes from that planning, not from technology in the operating room.