The use of computer-assisted surgery by orthopedic surgeons experienced in the performance of total knee arthroplasty may result in better overall limb and implant alignment and fewer outliers as compared with the findings after manual total knee arthroplasty.

The alignment results in previous studies were based on radiographic measurements. The sensitivity of radiographic assessment of limb and implant alignment may not be significant enough to distinguish small differences between computer-assisted surgery and manual techniques.

It is possible that alignment differences that were too minor to be exposed on standard radiographs might result in long-term differences in the durability of arthroplasties performed with use of computer-assisted surgery or manual techniques.

Moreover it is possible to measure additional implant positioning parameters with computed tomography (CT) technology.

In this study, the investigators would like to add new method, for accurate measurement of implant alignment and to correlate its results with clinical data.

Inclusion Criteria:

• Signing informed consent

Exclusion Criteria:

• Pregnancy
• Soldiers in active military service

men and women that are candidates for total knee replacement.