Related Experiment Video
Updated: May 1, 2026
Three-Dimensional Preoperative Virtual Planning in Derotational Proximal Femoral Osteotomy
Published on: February 17, 2023
Evidence of trochlear dysplasia in patellofemoral arthroplasty designs
Mo Saffarini1, Panagiotis G Ntagiopoulos, Guillaume Demey
1Accelerate Innovation Management SA, 1 Rue de la Navigation, 1201, Geneva, Switzerland, saffarini@mac.com.
Purpose:
The design of the trochlear compartment is crucial in patellofemoral arthroplasty (PFA), because 78% of patients with isolated patellofemoral arthritis present concomitant trochlear dysplasia with patellar maltracking and therefore remain predisposed to post-operative patellar subluxation and dislocation. The study investigated whether current PFA implants are designed with anatomic trochlear parameters such as the sulcus angle, lateral facet height and groove orientation.
Methods:
Five trochlear components of commercially available PFA implants were scanned, and the generated three-dimensional surfaces were measured using engineering design software. The mediolateral trochlear profiles were plotted at various flexion angles (0°, 15°, 30° and 45°) to deduce the following variables: sulcus angle, height of lateral facet and trochlear groove orientation.
Results:
Four specimens had sulcus angle>144° in the 45° of flexion, and all five specimens had sulcus angle>143° in 30° of flexion. Three specimens had a facet<5 mm high through the entire range of early flexion (0°-30°), and two specimens had a facet<5 mm high beyond early flexion (30°-45°). The trochlear groove was oriented laterally in all specimens (range 1.6°-13.5°).
Conclusion:
Current PFA trochlear components are not always designed with anatomic parameters, and some models exhibit characteristics of trochlear dysplasia. Surgeons are therefore advised to implant components with a deep sulcus, particularly in patients with history of patellofemoral disorders, and to adapt the surgical technique and extensor mechanism if the component implanted has a shallow sulcus, to ensure normal patellar tracking.
Level Of Evidence:
III.
