This study proposes a new approach to evaluate the patellofemoral tracking using a knee model composed of femur, tibia, and patella reconstructed with a three-dimensional (3D) printer. Magnetic resonance images were used to create a CAD (Computer-Aided Design) file that is subsequently used as input for a 3D printer machine. Artificial ligaments were used to mimic the stability of the knee. The quadriceps tendon was simulated using a polyvinylchloride cord attached to the tibial insertion and the patella. The model was fixed to a tensile test machine and four static tests were performed by applying 200 N load in the proximal–distal direction through the cord at 30°, 60°, and 90° of knee flexion. The position of the patella was measured using a motion-tracking system with a custom-made navigation system. The mediolateral displacement of the patella was 1.01 ± 0.13 mm at 30° of knee flexion and 7.99 ± 0.07 mm at 90° of flexion. The patella lateral tilt was 2.79° ± 0.67° at 30° of flexion and 6.42° ± 0.11° at 90° of flexion. In conclusion, our low-cost knee model closely simulates the patellar behavior of cadaveric specimens as the results are in agreement with literature data on similar static in vitro experiments.
Gervasi, G. L., Tiribuzi, R., Georgoulis, A., Cerulli, G. G., Freddolini, M., A Novel Approach for Patellofemoral Tracking Using a Knee Model Reconstructed with a Three-Dimensional Printer, <<3D PRINTING AND ADDITIVE MANUFACTURING>>, 2016; 3 (1): 32-38. [doi:doi:10.1089/3dp.2015.0016] [http://hdl.handle.net/10807/82980]