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

With good positioning, a knee replacement can keep working for decades. The most extensive review of national joint registries found that about 82% of total knee replacements and 70% of partial knee replacements were still functioning a full 25 years after surgery.[5]

NanoKnee puts its focus on the factors that help implants endure. By combining precise 3D modeling and engineering with FDA-cleared implants, we build a plan that positions and aligns your implant to your specific anatomy. Component position and balance are among the variables the surgical team can control that influence how long a knee replacement lasts.[2]

If a doctor has told you that you need a knee replacement, and you want to heal at home, stay active, and have your implant planned around your anatomy, NanoKnee may be a strong fit. It was designed for active people who want top-level function after surgery, including younger patients and healthy older adults. Your surgeon will look at your imaging, health, history and goals during your consultation to confirm whether you're a candidate.

Knee replacement ranks among the most common and most thoroughly researched operations in the United States, with more than 4.4 million hip and knee replacements logged by the American Joint Replacement Registry since 2012.[6] Serious complications are uncommon, and some risks hinge on decisions made before surgery.

A national analysis of more than 380,000 joint replacements tied spinal (neuraxial) anesthesia to lower 30-day mortality and fewer in-hospital complications compared with general anesthesia.[7] Board-certified orthopedic surgeons perform NanoKnee procedures under spinal anesthesia with sedation.

NanoKnee relies on restricted inverse kinematic alignment (iKA), a personalized method that brings back your natural tibial joint line and alignment within safe limits. No two healthy knees are identical, and a meaningful share of adults naturally have knees that aren't in “neutral” mechanical alignment.[10] In a matched series, patients aligned with this method reported greater satisfaction and higher Oxford Knee Scores at one year than those aligned to an adjusted mechanical target.[11] Your plan is created from your CT scan ahead of surgery and checked by your surgeon.

If arthritis affects only part of your knee, you may have alternatives. NanoKnee surgeons perform partial (unicompartmental) and bicompartmental knee replacement, resurfacing only the worn one-third or two-thirds of the joint while keeping your ligaments and healthy bone intact. A randomized trial of 528 patients with arthritis limited to the inner compartment found that partial knee replacement produced equivalent improvement with fewer complications.[12][13] Your NanoKnee surgeon will discuss which option suits your anatomy and knee condition.

When arthritis is confined to a single compartment, a Nano partial knee replacement is the least invasive route, removing the least bone and preserving your ligaments.[12] For total knee replacement, how the surgery is planned and performed matters more than the length of the incision. Our advanced 3D modeling allows NanoKnee surgeons to use a quadriceps-sparing approach for suitable candidates, reaching the joint without cutting the quadriceps tendon. Randomized trials have shown this approach eases pain in the first days after surgery.[8]

Usually not. NanoKnee surgeons use spinal (regional) anesthesia with a local anesthetic block and “twilight” sedation, so you stay comfortable and unaware during surgery without a general anesthetic. In a national analysis of more than 380,000 joint replacements, spinal anesthesia was connected to lower 30-day mortality and fewer complications than general anesthesia.[7] General anesthesia is used only when it is the safer choice for an individual patient.

Yes, in most cases. NanoKnee procedures are outpatient surgeries, and most patients are discharged from the surgery center about two hours afterward. A meta-analysis of 20 studies found that appropriately selected outpatients had complication and readmission rates on par with inpatients.[9] Your surgeon will make sure going home the same day is the right choice for you.

A NanoKnee procedure usually takes about 90 minutes. Because your implant's size, position and alignment are finalized in your 3D plan beforehand, fewer choices are left to be made under pressure in the operating room.

Most NanoKnee patients are walking within 90 minutes of surgery and handling light activities during week one. A general outline:

• 7–14 days: daily routines
• 2–4 weeks: moderate activity
• 4–8 weeks: a fully active lifestyle

Individual recovery times vary, and your surgeon will guide your progress.

Most NanoKnee patients heal with a home exercise program directed by their surgeon, without formal outpatient physical therapy. Walking, isometrics and stretching start right away, followed by strengthening, biking, and activities like golf and hiking. With the NanoKnee app, you can track your progress and message your care team directly.

Most NanoKnee patients return to the pursuits they enjoy, including hiking, cycling, golf, tennis, running and skiing.

Most NanoKnee patients regain the motion they need for everyday life and sports, and many recover movement lost to years of arthritis. Your 3D plan is designed to balance your ligaments throughout the full range of motion, supporting a knee that bends and straightens completely. In our recovery-unit records for 720 NanoKnee patients, median knee flexion right after surgery was 125°, with half of patients falling between 120° and 134°.

Most incisions heal within two weeks, though you'll need to protect the area for the first two to three months. A cosmetic, plastic-surgical closure is part of every NanoKnee procedure to keep scarring to a minimum.

General knee replacement risks include infection, blood clots, stiffness, instability, implant loosening over time, and the risks of anesthesia. NanoKnee's surgical processes and proprietary 3D Blueprinting® are designed to 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 issues that rank among the leading causes of early revision.[1] Your NanoKnee surgeon will go over the risks that apply to you.

For most patients, function returns gradually and arthritis pain fades over the months following surgery. Some numbness near the incision and an occasional clicking sound are common and generally harmless. Your surgeon will keep an eye on your recovery and address anything that isn't progressing as it should.

Medicare and most commercial health plans cover knee replacement when it is medically necessary, and NanoKnee surgery is billed as a knee replacement. Pre-operative 3D planning and engineering fall outside insurance coverage, and depending on your plan, your share could be up to $8,500. Our patient navigators will confirm your coverage and expected out-of-pocket costs before you commit to surgery, and financing is available for anything insurance doesn't cover.

Yes. Older adults with advanced arthritis routinely undergo knee replacement, and many enjoy major gains in mobility and quality of life. Overall health matters more than age when determining candidacy, and every NanoKnee patient is evaluated before surgery. Spinal anesthesia, which NanoKnee uses by default, is associated with fewer perioperative complications than general anesthesia.[7]

NanoKnee is not robotic surgery: your surgeon performs the operation, and no robot is involved in the operating room. AI plays a role only before surgery, helping our biomedical engineers turn your CT scan into a 3D model, and your surgeon reviews and approves the final plan. NanoKnee's precision is built into that pre-operative plan rather than into technology in the operating room.