Cadaveric assessment of a 3D-printed aiming device for implantation of a hinged elbow external fixator.

Abstract

Proper implantation of a hinged external elbow fixator (HEEF) is demanding since it requires precise alignment between the flexion-extension's and HEEF's axis. In order to optimize this alignment, we have developed a 3D-printed aiming device. The primary goal of the study was to compare the aiming device-based technique with the conventional pin technique. The secondary goal was to determine whether it is possible to share the aiming device with the surgical community. A HEEF was implanted in cadavers with either the aiming device (n = 6) or the conventional pin technique (n = 6). For both techniques the duration of the procedure, the radiation exposure as well as the offset and angular divergence between the HEEF's and flexion-extension's axis were compared. To achieve the secondary goal, two surgeons used aiming devices 3D-printed from files sent by email in order to implant HEEF on cadaveric specimens (n = 6). Duration of the procedure was not significantly different between both techniques. However, the aiming device allowed for reduction of the number of image intensifier shots (p = 0.005), angular divergence (p = 0.02) and offset between both axes (p = 0.05). The aiming devices have been delivered less than 15 days after ordering, and they have allowed proper implantation of six HEEF. The 3D-printed aiming device allowed less irradiant and more accurate implantation of HEEF. It is possible to share it with other surgeons.