Influence of the Vertek aiming device on the surgical accuracy of computer-assisted drilling of the equine distal sesamoid bone-An experimental cadaveric study.

Objective: To determine the effect of the Vertek aiming device (VAD) on the surgical accuracy of navigated drilling of the distal sesamoid bone (DSB).

Study Design: Experimental cadaveric study.

Sample Population: A total of 30 paired equine cadaveric limbs from 15 horses.

Methods: Each specimen was placed in a purpose-built frame (PBF). Preoperative cone beam computed tomography (CBCT) images were acquired with an imaging unit coupled with a surgical navigation system. In the DSB of each specimen, a 4.5 mm glide hole and a 3.2 mm thread hole were drilled under navigation guidance, to simulate drilling for the repair of a mid-sagittal DSB fracture. In the VAD group navigated drilling was assisted by using the VAD. In the free-hand drilling group navigated drilling was performed without the VAD. Pre-and postoperative CBCT scans were merged and surgical accuracy aberrations (SAA) between the planned drill corridor and the created bone tunnel were measured. Descriptive statistics and repeated-measures analyses of variance (rep.-meas. ANOVA) were performed to compare SAA measurements between the study groups.

Results: The SAA measurements ranged from 0 to 2.9 mm in the free-hand group and from 0 to 2.8 mm in the VAD group. The median overall SAA was lower in the VAD group than in the free-hand navigated group (0.6 mm ± [0.5-0.7] vs. 0.8 mm ± [0.7-1], rep.-meas. ANOVA p = .007).

Conclusion: The additional use of the VAD in the described set-up for navigated drilling significantly improved surgical accuracy.

Clinical Significance: The combined use of the VAD and PBF may help improve surgical accuracy in navigated lag screw repair of DSB fractures.