Surgical Technique

Functional positioning 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, 25124 Brescia, Italy
³ School of Rehabilitation Health Sciences, University of Patras, 26504 Greece
⁴ Fondazione Policlinico Universitario Campus Bio-Medico, 00128 Roma, Italy
⁵ LIBM-EA 7424, Interuniversity Laboratory of Biology of Mobility, Claude Bernard Lyon 1 University, 69100 Lyon, France
⁶ Univ Lyon, Claude Bernard Lyon 1 University, IFSTTAR, LBMC UMR_T9406, 69622 Lyon, France

^* Corresponding author: andriollo.luca@gmail.com; luca.andriollo@poliambulanza.it

Received: 7 April 2025
Accepted: 1 May 2025

Abstract

Patello-femoral arthroplasty (PFA) is an effective treatment option for isolated patello-femoral osteoarthritis. However, challenges remain regarding implant positioning and patellar tracking. Recent advances in implant design and robotic-assisted techniques have contributed to more personalized and reproducible procedures. Functional positioning (FP), a three-dimensional alignment concept, introduces a customized approach to optimize trochlear resurfacing and restore joint kinematics of the anterior compartment. This article presents a step-by-step surgical technique for PFA using FP principles in combination with an image-based robotic system. The technique ensures accurate preoperative planning, real-time intraoperative adjustments, and precise component placement. The key steps of this surgical technique include trochlear resurfacing assisted by an image-based robotic system and the restoration of patellar tracking, following a step-by-step approach that is both effective and reproducible. The use of FP enables personalized anterior compartment restoration, avoiding overstuffing and improving patellar tracking. Future studies will help refine FP strategies and further optimize outcomes in these patients.