AUTHOR=Zhang Lei , Xu Junjie , Tang Xiangyu , Zhou Xin , Li Bingkun , Wang Guoyou 

TITLE=A Novel Adjustable EndoButton Fixation Assisted by 3D Printing Technology for Tibiofibular Syndesmosis Injury: A Biomechanical Study

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=Volume 10 - 2022

YEAR=2022

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2022.793866

DOI=10.3389/fbioe.2022.793866

ISSN=2296-4185

ABSTRACT=Purpose: The recommendations for surgical fixations of tibiofibular syndesmosis injury are increasingly challenging for many clinical orthopedists, as international consensus has not been published for the optimal treatment of the injury. Thus, we have created a 3D-printed navigation template for a precise bone tunnel and a novel adjustable Endobutton fixation (NAE) for the ideal treatment. The purpose of this research was to evaluate the accuracy of the 3D-printed navigation template and explore the biomechanical performance of the NAE technique by comparing with the intact syndesmosis, screw technique and TightRope (TR) technique. 
Methods: Twenty-four human cadaveric legs were randomly allocated to four groups: the NAE group (n=6), the TR group (n=6), the screw group (n=6) and the intact group (n=6). A personalized navigation template based on computed tomography scans was designed and 3D printing models were generated for the distal tibiofibular syndesmosis. The NAE, TR and screw group were performed via 3D-printed navigation template respectively. All groups were tested under increasing loading force experiments including axial loading (from 100N to 700N) and torsional loading (from 1N to 5N) which were performed in different ankle positions. The displacements of the tibiofibular syndesmosis were analysed using a 3520-AT Bose Electroforce biomechanical testing equipment.
Results: Surgical fixations were conducted successfully through 3D-printed navigation template. Whether in axial or torsional loading experiments, no statistically significant difference was observed in the displacements among the NAE, TR and intact group in most situations (P>0.05), whereas screw group demonstrated obviously smaller displacements than the above three groups (P<0.05). 
Conclusion: The 3D printing technology application may become beneficial and favorable for locating and making the bone tunnel. And the NAE fixation provides the performance of complete ligaments; it also restores physiologic micromotion and avoids insufficient or excessive reduction when compared to TR and screw technique. This may offer a new fixation for the treatment of tibiofibular syndesmosis injury that is desirable for clinical promotion.