A Novel Fibula Malleolus Cap to increase the accuracy of computer-assisted jaw reconstruction: a comparative study

Abstract

PURPOSE: Although computer-assisted surgery for jaw reconstruction using fibula flap has been widely used nowadays, the inaccurate positioning of fibula harvest guide brings sliding and rotational errors. We aim to develop a novel 3D-printed patient-specific fibula malleolus cap to help reduce the errors of the fibula harvest guide, thus leading to increased reconstruction accuracy. METHODS: This two-armed retrospective comparative study was conducted to evaluate the effectiveness of the malleolus cap design. Eighteen patients underwent fibula reconstruction of jaw defects by the same surgical team were enrolled, with 8 patients in the malleolus cap group and 10 in the control group without malleolus cap design. CT scans of donor and recipient sites were performed pre- and post-operatively. Three-dimensional models were built based on the post-operative CT scans and compared with the pre-operative virtual surgical planning. Deviations of location and angulation of distal fibula osteotomies, jaw reconstruction segments and simultaneous dental implants were compared between two groups. RESULTS: With the malleolus cap, there were reduced deviations in locations and angles of fibula osteotomies from 9.8mm to 4.0mm (p=0.024) and 26.2 to 6.7 degrees (p=0.001) respectively. Thirteen and eighteen simultaneous dental implants were placed in malleolus cap and control groups respectively. There were significant increase in accuracy of implant platform locations (from 3.2mm to 1.4mm, p<0.001), apex locations (from 3.8mm to 1.6mm, p<0.001) and angles (from 11.0 to 4.2 degrees, p=0.001). There were 17 and 20 fibula reconstruction segments included in malleolus cap and conventional groups respectively. No significant differences were detected among two groups in terms of deviations in locations of segment centers or segment angles. CONCLUSION: The design of a novel 3D-printed patient-specific fibula malleolus cap significantly reduced the sliding and rotational errors of the fibula harvest guide and increased the accuracy in bone osteotomies and simultaneous dental implants in fibula free flap reconstructions of jaws. [https://ahns.jnabstracts.com/Detail?ID=90503]