A comparative study of clinical and radiographic outcomes in total knee arthroplasty assisted by the CT-free Smith & Nephew CORI robotic system versus the Brainlab Knee3 navigation system

The CT-free Smith & Nephew CORI robotic system and the Brainlab Knee3 navigation system represent two distinct technological approaches for assisting total knee arthroplasty (TKA). In this retrospective comparative study, 100 consecutive patients with knee osteoarthritis who underwent TKA from December 2020 to June 2025 were allocated to either a robotic-assisted group (n = 50) utilizing the CT-free CORI system or a navigation-assisted group (n = 50) utilizing the Brainlab Knee3 system. Perioperative parameters, early and mid-term functional scores, radiographic alignment, complications, and patient satisfaction were analyzed. The results demonstrated that while both systems achieved comparable long-term functional outcomes and similar safety profiles, the CORI robotic system showed distinct advantages. It significantly reduced osteotomy time, total operative time, and intraoperative blood loss. Patients in the CORI group also experienced less early postoperative pain, better knee function, and higher range of motion at 3 days postoperatively. Radiographically, the CORI group achieved superior accuracy in restoring the hip-knee-ankle angle and controlling the coronal alignment of the femoral and tibial components. These findings suggest that although both systems are effective for TKA, the CORI robotic system offers enhanced operative efficiency, reduced early surgical trauma, faster initial recovery, and improved precision in achieving targeted mechanical alignment.