Navio With Total Knee Arthroplasty

Total Knee Arthroplasty (TKA) has become an effective and reliable treatment for arthritis of
the knee (1). TKA is associated with low morbidity and mortality, and its effectiveness in
reducing joint pain and improving range of motion is well established. In 2014, over 750,000
knee replacements were performed in the US (2).

A significant innovation in TKA has been the introduction of computer navigation and
robotic-assisted surgery (3). One such technology is the Navio™ Robotic-assisted Surgical
System. This system is a semi-autonomous image-free system. During the surgery, the surgeon
maps the condylar landmarks and determines alignment indices to define the volume and
orientation of bone to be removed. The tools to remove the bone and place the implants are
controlled and manipulated by the surgeon with the guidance of a 3-dimensional digital map of
the surgical surface.

Originally the Navio™ system was launched for use in unicondylar knee replacement only. To
date, there have been over 1000 unicondylar knee replacement surgeries using the system. In
2017, Smith & Nephew Inc. expanded the indications for the Navio™ system to include TKA. The
purpose of this multicenter, prospective study is to evaluate outcomes associated with this
new indication.

Inclusion Criteria:

1. Subject requires primary total knee arthroplasty with the Journey II BCS or
Cruciate-Retraining (CR) Systems due to degenerative joint disease (primary diagnosis
of osteoarthritis, post-traumatic arthritis, avascular necrosis, rheumatoid arthritis.

2. Subject was considered skeletally mature at the time of cone implantation (at least 18
years or older.)

3. Subject agrees to consent to and to follow the study visit schedule (as defined in the
study protocol and informed consent form) by signing the IRB/EC approved informed
consent form.

4. Subject plans to be available through two (2) years postoperative follow-up.

Exclusion Criteria:

1. Subject has BMI ≥ 40.

2. Subject has condition(s) that may interfere with the TKA survival or outcome (i.e.,
Paget's or Charcot's disease, vascular insufficiency, muscular atrophy, uncontrolled
diabetes, moderate to severe renal insufficiency or neuromuscular disease, or an
active, local infection).

3. Subject is deemed by investigator to require a constrained or deep dish tibial insert.

4. Subject has inadequate bone stock to support the device (severe osteopenia, history of
severe osteoporosis or severe osteopenia).

5. Subject has mental or neurologic condition(s) that may pre-empt the ability or
willingness to restrict activities.

6. Subject is 80 years of age or older.

7. Subject is a prisoner or impending incarceration.