This study is a retrospective, multi-center study, with one single remote follow up contact. This study will include a minimum of 80 patients and a maximum 100 patients who have been treated with the ConforMIS iTotal PS knee product.

Patients will be contacted either by phone or email for a single remote follow-up. Retrospective data will be collected from medical records including pre-operative, operative and any follow up visits which have occurred since implantation as available. . All data will be collected from existing medical records and from single follow up call/email.

• Demographics and Medical History

• Pre & Post-Operative Data including Range of Motion

• Surgical Data

• Survivorship (phone/email or last known visit)

• Patient Reported Outcomes (phone/email single time point visit)

  • Patient Satisfaction
  • KOOS Jr.

Inclusion Criteria:

1. Previously underwent surgical implantation of a ConforMIS iTotal PS knee replacement.
2. Over 18 Years of age

Exclusion Criteria:

1. BMI > 40

Individuals who are 18 years or older and have received a ConforMIS iTotal PS knee replacement to treat any condition indicated on the device's instructions for use.