3D printed aiming device for equine proximal interphalangeal joint arthrodesis: Ex vivo study

To determine the benefit of using a three-dimensional (3D)-printed titanium aiming device for placing two 5.5-mm transarticular screws during proximal interphalangeal joint (PIPJ) arthrodesis in equine species.

Ex vivo study.

A total of 40 cadaveric forelimbs from adult horses.

A senior surgeon and a first-year resident each performed 20 constructs: 10 using the device and 10 using a freehand technique. Procedure duration and number of intraoperative radiographs were recorded. Final radiographs were evaluated by an ECVS-certified surgeon unaware of treatment group, based on two criteria: compliance with the AO principles, and symmetry and homogeneity of the construct. Following implants removal, the position of the thread hole on the articular surface of the second phalanx was assessed and graded for accuracy.

For the inexperienced surgeon, the device reduced mean procedure time from 27.24 to 20.16 min (-25%, p < .01), decreased mean radiograph number from 6.1 to 2.1 (-60%, p < .01), and improved mean accuracy scores from 4.4 to 5.8 (+31%, p < .01). Construct symmetry also improved from 1.5 to 2.2 (+47%, p < .05). For the senior surgeon, only the number of radiographs was significantly reduced, from 3.1 to 1.3 (-58%, p < .01), with no significant difference in duration, accuracy, or symmetry.

The aiming device improved feasibility, accuracy, and repeatability of transarticular screw placement for the inexperienced surgeon.

This 3D-printed device appears to be as a promising tool for achieving gold-standard transarticular screw placement and may increases the accuracy of this surgery.