A Prospective Study to Evaluate the ConforMIS iTotal® (PS) Knee Replacement System

The study is prospective. Subjects will be implanted with an iTotal® PS Knee Replacement
System. The study will include a minimum of 100 subjects across up to 10 sites. The patients
enrolled in this study may represent the first cases of the iTotal PS KRS implanted at a
particular site; data collected for the first 15 patients at each site will be analyzed
separately from the rest of the enrolled population. This will provide visibility towards
determining if there exists a learning curve in the implantation process of the iTotal PS
KRS. The study sites will be located in the United States.

Inclusion Criteria:

- Clinical condition included in the approved Indications For Use for the iTotal® PS

- Osteoarthritis, as confirmed by the investigator's assessment of disease status at
screening visit that warrants a TKR procedure. Disease status is assessed by Clinical
and Radiographic assessment.

- Willingness to participate in the clinical study, to give informed consent, and to
attend all follow-up visits

- > 18 years of age

Exclusion Criteria:

- Simultaneous bilateral procedure required

- BMI > 40

- Active malignancy (defined as a history of any invasive malignancy - except non-
melanoma skin cancer), unless patient has been treated with curative intent and there
have been no clinical signs or symptoms of the malignancy for at least 5 years

- Poorly controlled diabetes

- Neuromuscular conditions which prevent patient from participating in study activities

- Active local or systemic infection

- Immunocompromised

- Fibromyalgia or other general body pain related condition

- Rheumatoid arthritis or other forms of inflammatory joint disease

- Loss of bone or musculature, osteonecrosis, neuromuscular or vascular compromise in
the area of the joint to be operated on, to an extent that the procedure is
unjustified

- Diagnosed with or receiving treatment for Osteoporosis

- Other physical disability affecting the hips, spine, or contralateral knee

- Severe instability due to advanced loss of osteochondral structure

- Prior arthroplasty of the affected knee, including High Tibial Osteotomy (HTO)

- Unwilling or unable to comply with study requirements

- Participation in another clinical study which would confound results

- Allergy to any of the implant materials