Objective: (1) To establish a III°PCL injury model on fresh cadaver knee specimens, and to define the pathological and anatomical connotation of III°PCL injury by using anatomical methods.~(2) To explore and establish combined reconstruction techniques, including PCL reconstruction combined with injury repair and reconstruction, and to explore the role of combined reconstruction techniques in maintaining knee stability through biomechanical experiments.~Design: ① The subjects of this study were fresh cadaver knee specimens.~Sample size:~A Anatomical study of injury model, planning 6 cases. B. Exploration of treatment methods for complicated injuries. 8 cases of specimens are planned to be used. According to the pathological and anatomical content of III°PCL injury (IKDC standard), the repair and reconstruction techniques of combined injury were designed. Arthroscopic transtibial single-bundle PCL reconstruction technique was used in all the reconstruction of PCL. Using the robotic arm or universal sensor test system as the biomechanical test platform, Biomechanical tests were carried out on the experimental specimens, and the results were compared to determine the shortcomings of the new PCL reconstruction, according to which the surgical procedures were improved, and then the biomechanical tests were carried out. After repeated technical improvement (4 cycles, 2 specimens per cycle), the new PCL reconstruction technique was finally determined.~C To investigate the effect of new PCL reconstruction in maintaining the stability of knee joint, 8 cases were treated with a specimen plan. Biomechanical tests were performed on each specimen in its intact state, post-traumatic state (after the establishment of the III°PCL injury model), and post-traumatic state (after the application of the new PCL reconstruction technology) using the robotic arm/universal sensor test system.~Outcome evaluation: The biomechanical characteristics of knee specimens under different conditions were measured, compared and statistically analyzed, and the conclusions were drawn.~Statistical Methods:~Multivariate linear analysis model and Bonferroni multiple comparison were used to compare the kinematics changes of knee joints under various loading conditions and knee flexion angles under the condition of knee joint integrity, III°PCL injury, PCL reconstruction, and combined injury treatment.~Univariate repeated measure ANOVA was used to compare the knee joint integrity, III°PCL injury, the stability of the knee joint after PCL reconstruction, and the stability of the knee joint after combined injury treatment (including the back drawer test and stress radiograph measurement).
To establish a III°PCL injury model on fresh cadaver knee specimens, and to define the pathological and anatomical connotation of III°PCL injury by using anatomical methods.~To explore and establish combined reconstruction techniques, including PCL reconstruction combined with injury repair and reconstruction, and to explore the role of combined reconstruction techniques in maintaining knee stability through biomechanical experiments.