Application of a Personalized Finite Element Analysis and 3D-Printed Navigation Template in the Treatment of Femoral Neck Fracture with Cannulated Screw

To investigate the feasibility and accuracy of combining a personalized finite element analysis with 3D-printed navigation template on the treatment of femoral neck fracture (FNF) with cannulated screw. A total of 60 patients as unstable FNT were evolved and randomly divided into two groups. The subjects in the study group were examined using a finite element analysis according to the three-dimensional CT of hip joint before operation and then underwent 3D-printed navigation template of the femur to complete the implantation of cannulated screw, whereas the other 30 patients in the control group were underwent the implantation of cannulated screw using the conventional FNF treatment. The biomechanics of three screws were more stable when they were close to the bone cortex (< 3 mm). Furthermore, it was demonstrated that the patients in the study group had more effectively success rate of one-time nail placement and significant reduction in the distance of talus cortex than those in the control group. At 12 months post-surgery, higher healing rate of fracture and Harris functional score of hip, as well as lower necrosis rate of femoral head were underwent in the study group when compared to the control group. Totally, the combined application of a personalized finite element analysis and 3D-printed navigation template in the treatment of FNF can not only improve the effective nail placement, but also make the screw more in line with the requirements of biomechanical stability to promote the fracture healing and reduce the risk of femoral head necrosis.