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

Introduction

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.

Materials and methods

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).

Results

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.

Conclusion

The 3D-printed aiming device allowed less irradiant and more accurate implantation of HEEF. It is possible to share it with other surgeons.