knee joint 3d model

Create a highly detailed, anatomically accurate 3D model of a human knee joint for 3D printing. Include realistic femur, tibia, and patella with correct proportions and surface detail. Design a modular total knee replacement system with three detachable components: femoral implant, tibial tray, and polyethylene insert. Each implant must attach/detach from the bone using printable mechanisms like pegs, stems, or snap-fit connectors with proper tolerances. Ensure correct alignment: femoral component on distal femur, tibial component on proximal tibia, and insert fitting securely between them. Maintain smooth articulating surfaces and realistic joint spacing based on real orthopedic designs. Optimize for 3D printing with manifold geometry and adequate wall thickness. Provide both assembled and exploded views, with clean, medical-grade realism suitable for educational use.