A Retrospective Study of the Navio (NAVIO)

Inclusion Criteria:

1. Male or female subjects ≥ 18 years old (at the time of surgery) who have undergone Navio System-assisted UKR at least 2 years prior to enrollment. This includes UKR procedures with all Unicondylar Knee cemented implant designs.
2. Subject had a primary diagnosis of unicompartmental, non-inflammatory degenerative joint disease including osteoarthritis, traumatic arthritis, or avascular necrosis, required correction of functional deformity, or required treatment of fractures that were unmanageable using other techniques.

Exclusion Criteria:

1. Subject received the Navio System-assisted UKR on the index joint as a revision for a previously failed UKR.
2. Subject, in the opinion of the Investigator, had advanced osteoarthritis or joint disease at the time of surgery and was better suited for Total Knee Arthroplasty (TKA).
3. Subject, in the opinion of the Investigator, had a neuromuscular disorder that prohibited control of the index joint.
4. Subject, in the opinion of the Investigator, was morbidly obese.
5. Subject, in the opinion of the Investigator, was contraindicated for UKR.
6. Subject (prospective subjects only), in the opinion of the Investigator, has an emotional or neurological condition including mental illness, mental retardation, drug or alcohol abuse.
7. Subject (prospective subjects only) is a prisoner.