NAVIO* Partial Knee Replacement

Partial knee replacement with the NAVIO* Surgical System

For people suffering from knee pain caused by osteoarthritis, whose damage is limited to a single compartment or area of the knee, partial knee replacement may be an option. In partial knee replacement, your supporting tissue and ligaments that help stabilise your knee are spared and only the damaged portion of the knee is replaced. This means that healthy cartilage and bone remain intact to help your knee joint move smoothly with the prosthetic implant. Patients with osteoarthritis in only one area of their knee may be candidates for partial knee replacement. 

Patients who undergo partial knee replacement often report a 'more normal' feeling knee, less pain and quicker rehabilitation.1 

The NAVIO Surgical System uses robotics assisted technology to help tailor partial knee replacement procedures to the unique shape and motion of each patient's knee anatomy.

NAVIO Hand-piece

Robotics-assisted Surgery

While it may seem counterintuitive (not obvious), replacing only part of a knee joint can be more challenging than replacing the entire joint. This is because partial knee replacement must achieve an exact balance between the new implant - made of metal and plastic components - and the remaining portions of your natural anatomy made of bone and cartilage. As a result, one of the primary challenges of all partial knee replacements is precisely positioning the implant for each unique patient. Even minor changes in an implant's size or placement can cause the knee to function poorly or result in early failure of the implant and the need for future surgery. The NAVIO Surgical System addresses the challenge of partial knee replacement by using both computer and robotic assistance to accurately map the surface of your knee, align your implant to your anatomy, and physically remove the bone necessary to place your new implant.2 This added level of assistance is important because implant alignment is a crucial factor in determining how long the implant will last. 3,4

NAVIO Robotics assistance facilitates accuracy and precision

The NAVIO system is an advancement in the way orthopaedic surgeons perform partial knee replacement. The system works in conjunction with your surgeon's skilled hands to achieve the precise positioning of the knee implant based on each patient's unique anatomy, which can help improve the function, feel and potential longevity of the partial knee implant. Through an advanced computer program, the NAVIO system provides robotic assistance that relays precise information about your knee to a robotics-assisted hand piece used by your surgeon during the procedure. By collecting patient-specific data, boundaries are established for the hand piece so that the surgeon can remove the damaged surfaces of your knee, balance your joint, and position the implant with greater precision.

NAVIO Precision

Robotic Knee Surgery without Radiation

Other robotic knee replacement systems use computerised tomography, or CT, scans to help a surgeon visualise a patient's knee anatomy. While CT scans are effective at showing the layers of knee anatomy, they can expose the patient to potentially harmful radiation. In fact, a single CT scan is equivalent to the radiation exposure received in 48 chest X-rays.4 The NAVIO system eliminates the need for CT scans by using an advanced computer program (similar to GPS navigation on your phone) to collect anatomic (body structure) and alignment information about your knee. Once captured, this information is used to build a precise, computer-rendered 3D model of your knee that your surgeon will use to plan your surgery.

NAVIO Robotics-assisted Partial Knee Replacement Surgery

After all of the information about your knee is gathered and your surgical plan is created, your surgeon will use a robotics-assisted surgical tool (the NAVIO hand piece) to physically remove the damaged surface of your bone so that your new implant fits properly. Using the same 3D model of your knee, the hand piece is able to differentiate between the damaged areas that need to be removed, and the healthy areas that will remain. The NAVIO hand piece uses a burr that removes damaged bone for your implant.

The NAVIO system does not replace your surgeon. Rather, it assists your surgeon by adding an extra layer of planning to the procedure.

Partial Knee Replacement with Traditional Techniques

Traditional knee replacementBy comparison, using traditional surgical methods, cutting blocks or guides are placed on the thigh bone (femur) and shin bone (tibia) to help direct a surgical saw in removing the diseased bone and cartilage. This method has been considered technically challenging, as accurately placing these blocks can be difficult. The NAVIO Surgical System helps tailor your partial knee replacement procedure.

Shin bone (tibia) guide          Thigh bone (femur) guide



Individual results may vary. There are risks associated with any surgical procedure including NAVIO enabled Knee Replacement. NAVIO is not for everyone. Children, pregnant women, patients who have mental or neuromuscular disorders (e.g. multiple sclerosis) that do not allow control of the knee joint, and morbidly obese (overweight) patients and patients contraindicated (not advised) for UKR (unicondylar knee replacement), PFA (patellofemoral arthroplasty) and TKA (total knee replacement) should not undergo a NAVIO procedure. Consult your surgeon for details to determine if NAVIO is right for you.

1. Hall et al., "Unicompartmental Knee Arthroplasty (Alias Uni-Knee): An Overview with Nursing Implications," Orthopaedic Nursing, 2004; 23(3): 163-171. 

2. Lonner, Jess, Moretti, Vince, "The Evolution of Image-Free Robotic Assistance in Unicompartmental Knee Arthroplasty." The American Journal of Orthopedics, May/June 2016, 249-254. Accessed June 7, 2016

3. Collier, Matthew, et al., "Patient, Implant, and Alignment Factors Associated With Revision of Medial Compartment Unicondylar Arthroplasty.", Jour of Arthro, Vol 21 No 6, Suppl. 2, 2006

4. Hernigou, Ph, Deschamps, G., "Alignment Influences Wear in the Knee after Medial Unicompartmental Arthroplasty.", ClinOrthopRelat Res., Volume 423, June 2004, pp 161-165