A Multicenter Study to Evaluate Functional Outcome After Knee Replacement

To compare functional and patient reported outcome data for a consecutively enrolled group of
subjects who have undergone surgery with either a ConforMIS iTotal® CR TKA or an Off-the-
Shelf (OTS) system.The person conducting the functional testing will be blinded to the device
implanted. Sites will perform the off-the-shelf total knees conventional instrumentation.

Inclusion:

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

- 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:

- Subject will require a simultaneous bilateral procedure

- Other lower extremity surgery within 1 year

- Severe (> 15º) fixed valgus or varus deformity

- Severe (> 15º) extension deficit

- Severe instability due to advanced loss of osteochondral structure

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

- Insufficient bone stock on the femoral or tibial surfaces

- Contralateral knee replacement surgery within the past 6 months

- 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 (defined as HbA1c >7 or surgeon discretion)

- Immunocompromised

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

- Disabling chronic pain with narcotic dependence

- Compromised PCL or collateral ligament

- Prior history of failed implant surgery of the joint to be treated, including
Unicompartmental Knee Arthroplasty (UKA), or Bicompartmental Knee Arthroplasty (BKA)

- Prior history of failed high tibial osteotomy (HTO)

- Participation in another clinical study which would confound results

- Inability to complete the protocol in the opinion of the clinical staff due to safety
or other reasons