Design of a multitissue osteoarticular 3D-Printed knee model for initial training in meniscal repair

Meniscal preservation is essential, given the degenerative risk associated with meniscectomy. Consequently, meniscal repair is a key technical skill to be acquired early during surgical training. However, resident education is limited by restricted access to human models. While artificial simulators represent an alternative, their use is often constrained by high cost and limited biomechanical or arthroscopic realism. The aim of this project was to design and evaluate a 3D-printed arthroscopic simulator dedicated to meniscal repair, developed through a collaboration between orthopedic surgeons and engineers, in order to provide an accessible and realistic educational tool.

Modeling and design were jointly performed by orthopedic surgeons and engineers based on segmentation of medical imaging data. A complete lower limb was created, incorporating a removable capsulomeniscal complex. Osseous and cartilaginous structures were produced by direct 3D printing, while ligaments and the capsulomeniscal complex were molded in silicone using 3D-printed templates. This removable complex differentiates peripheral capsular insertions from meniscal roots, reproducing the anatomical constraints. The model was assessed through a subjective evaluation of arthroscopic realism during meniscal suturing procedures by two independent knee surgery experts.

The prototype reproduces a complete lower limb articulated around a fixed femoral pivot, with near-physiological hip and knee motion. It allows dry arthroscopy for various meniscal tear patterns and requires Cabot and valgus maneuvers for optimal femorotibial exposure. Ramp lesions can be repaired via a postero-medial approach using a hook instrument, whereas osseous procedures such as meniscal root reinsertion remain unfeasible. Both evaluators rated as "very realistic" the anatomy, haptic feedback, and ramp lesion suturing. Overall, arthroscopic realism was rated as "very realistic" by both.

This study presents a realistic 3D-printed simulator for meniscal repair, addressing a clear educational need. Further development and large-scale validation studies involving trainees are required to confirm its pedagogical relevance. Study type / Level of evidence: Experimental design study / Level IV.