Assessment of Limb Alignment and Component Placement After All Burr Robotic-Assisted TKA.

BACKGROUND: All burr robotic-assisted total knee arthroplasty (R-TKA) is the new way of doing TKA without conventional jigs and saw. The aim of this study is to assess the accuracy of limb alignment and component placement after R-TKA. METHODS AND MATERIALS: This is the prospective study of 63 patients who underwent R-TKA between March and October 2019. Standing scanogram and AP/lateral radiograph were done on day of discharge, 5th day after surgery to calculate limb alignment and component placement angles in coronal and sagittal plane. Deformity correction Bone Ninja software had been used to calculate all this angles.
RESULTS: Mean difference between robotic achieved and postoperative limb alignment was 1.24°. Mean difference between planned and achieved component placement in coronal and sagittal plane for tibia was 0.33° and 0.66° and for femur was 0.62° and 0.30°, respectively. Posterior condylar offset difference was 0.03. As per planned by Navio software, R-TKA had reduced the overall outlier of coronal limb alignment from 3° to less than 1.2° and component placement malposition to less than 1° in coronal and sagittal plane.
CONCLUSION: R-TKA provides near perfect limb alignment and near accurate femoral/tibial component placement as planned in both coronal and sagittal plane. Posterior condylar offset was also perfectly maintained. R-TKA had reduced the overall outlier of coronal limb alignment from 3° to less than 1.2° and component placement malposition to less than 1° in coronal and sagittal plane. © Indian Orthopaedics Association 2020.