How and why we resurface the patella
Background: Although the clinical necessity of patellar resurfacing in total knee arthroplasty remains a subject of orthopedic debate, international registry data indicate lower revision rates when the patella is resurfaced during the primary procedure. As prosthetic designs and surgical technologies evolve, the epidemiology of failure mechanisms shifts, necessitating precise techniques to optimize patellofemoral kinematics and ensure long-term implant stability.
Objective: This article describes a standardized surgical technique utilizing inlay milling to consistently restore native patellar thickness and ensure stable tracking within the prosthetic trochlear groove.
Key Points: The primary surgical objectives include achieving a composite thickness equivalent to the pre-osteoarthritic state and ensuring adequate polyethylene coverage. Compared to traditional oscillating saw techniques, which may result in asymmetric resection, malalignment, or excessive bone loss, milling offers enhanced reproducibility and safety. This is particularly relevant for surgeons in training or in cases involving significant bone deficiency. The described technique involves initial thickness measurement followed by a lateral facetectomy to optimize capture ring stability. An inlay milling system is utilized to establish a precise resection plane, after which the peripheral bone rim is removed using rongeurs and an oscillating saw. To mitigate the risk of iatrogenic patellar fracture, a minimum residual bone thickness of 15 mm is maintained. Final assessment confirms medial patellar articulation with the trochlea at 30° of flexion, typically obviating the need for lateral retinacular release.
Conclusion: Inlay milling provides a safe and reproducible method for patellar preparation in total knee arthroplasty. This approach facilitates precise implant positioning and restores near-anatomic patellofemoral tracking, potentially contributing to improved clinical outcomes and reduced revision risk.
