Intraoperative Soft Tissue Balance in TKA

This is a single surgeon, prospective, controlled study consisting of 50 patients with a primary indication of OA who are eligible for primary total knee arthroplasty using the Persona total knee system. The patients are equally divided in two groups; patients in group 1 will receive traditional, manual soft-tissue balancing during surgery. For the purpose of the study, the balance will be quantitatively assessed at the end of the case, by means of surgeon-blinded VERASENSE measurements before and after cementation. For the patients in Group 2, intra-operative sensor feedback will be used in creating a quantitatively balanced knee (VERASENSE, OrthoSensor Inc.). Thereby, a quantitatively balanced knee is characterized by a mediolateral load differential below 15lbs at 10-45-90 degrees of flexion. Post-operatively, the patients will be evaluated using the Muvr device at the day of surgery, day of discharge and 2, 6, and 12 weeks, and 1 year postoperatively. This device will provide quantitative feedback on different gait metrics as well as function during activities of daily living such as stair climbing / stair descent, walking, and timed get up and go testing. During each post-operative visit, the following metrics will be recorded: * Active and passive range of motion * Implant alignment * Patient reported outcomes by means of Knee Society Score (KSS), Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and Forgotten Joint Score (FJS)