Surgical Technique

Enhancing patellar positioning and tracking in robotic patello-femoral arthroplasty: a step-by-step technique

¹ Orthopaedics Surgery and Sports Medicine Department, FIFA Medical Center of Excellence, Croix-Rousse Hospital, Hospices Civils de Lyon, Lyon North University Hospital, 103 Grande Rue de la Croix-Rousse, 69004 Lyon, France
² Ortopedia e Traumatologia, Fondazione Poliambulanza Istituto Ospedaliero, Via Bissolati 57, 25124 Brescia, Italy
³ Artificial Intelligence Center, Alma Mater Europaea University, Argentinierstraße 15, 1040 Vienna, Austria
⁴ Department Orthopedic Surgery – University Hospital Ghent, Corneel Heymanslaan 10, 9000 Ghent, Belgium
⁵ Department of Anatomical, Histological, Forensic Medicine and Orthopedic Science, Sapienza University of Rome, Viale Regina Elena 336, 00161 Rome, Italy
⁶ Sydney Adventist Hospital, 185 Fox Valley Road, Wahroonga (Sydney) NSW 2076, Australia
⁷ Sydney Orthopaedic Research Institute, 66 Pacific Highway, St. Leonards (Sydney) NSW 2065, Australia
⁸ Univ Lyon, Claude Bernard Lyon 1 University, IFSTTAR, LBMC UMR_T9406, 69622 Lyon, France
⁹ LIBM-EA 7424, Interuniversity Laboratory of Biology of Mobility, Claude Bernard Lyon 1 University, 69100 Lyon, France

^* Corresponding author: sebastien.lustig@chu-lyon.fr; sebastien.lustig@gmail.com

Received: 3 July 2025
Accepted: 6 July 2025

Abstract

Patellofemoral arthroplasty (PFA) is useful and effective option for treating patients with isolated patellofemoral osteoarthritis. The concept of functional positioning (FP) in PFA focuses on resurfacing the trochlea and restoring normal patellar tracking, while keeping the joint anatomy and kinematics. Even though the patellar liner cannot yet be placed with robotic assistance, robotic tools still help surgeons manage and optimize patellar tracking during surgery. This surgical technique highlights how the image-based robotic system assists the surgeon in improving patellar positioning and patellar tracking during a PFA. This technique could contribute to reduce complications, although its actual benefits remain to be validated. It may help prevent patellar instability through direct tracking assessment and reduce fracture risk by preserving more patellar bone. Accurate placement of the patellar button and evaluation of anterior offset might alleviate anterior knee pain. A tailored resection could also help protect the patellar vascular supply. Image-based planning may assist in avoiding malpositioning, potentially leading to fewer revisions.