Sixty obese patients with degenerative joint disease undergoing primary total knee arthroplasty were randomized to receive surgery with a computerized assisted stereotaxic navigation system (n=30) or with conventional instrumentation (n=30). The primary outcome was post-operative hip-knee-ankle (HKA) angle. Secondary outcomes included medial distal femoral angle (mMDFA), medial proximal tibial angle (mMPTA), and number of outliers beyond 3° of neutral alignment. Radiographs were assessed preoperatively and at 6 weeks. Overall, the study revealed no significant difference between navigation and conventional techniques in achieving post-operative HKA or in outlier rates. The findings suggest that in obese patients, computer navigation did not provide measurable advantages in coronal alignment compared with conventional methods.