Which of the following is part of steps required for both TKA and UKA registration?

• A. Ankle Center
• B. Hip Center
• C. Knee Center
• D. All of the Above

Answer: (B)

The main idea here is how surgeons establish a patient-specific coordinate system for knee arthroplasty. For both total knee arthroplasty and unicompartmental knee arthroplasty, locating the hip center provides a stable proximal reference that defines the leg’s axis from hip to ankle. This hip-centered frame lets the navigation or registration system determine the limb’s alignment and orientation accurately during planning and implantation. Ankle center and knee center aren’t universally required steps shared by both procedures in standard registration workflows, so they aren’t the consistent elements used to set up the reference frame across both TKA and UKA.