Evaluation of window trajectory in trans-iliac foraminotomy using an individualised 3D printing guide in cadaveric dogs

Importance: In veterinary orthopedics, addressing foramen stenosis in the L7-S1 region in dogs presents significant challenges due to limited access and visualization with conventional surgical techniques. Objective: This study aims to evaluate endoscopic foraminotomy through the iliac window, using three-dimensionally (3D) printing guide based on the preoperative plan, in cadaveric dogs. Methods: Trans-iliac foraminotomies were performed on each side of five canine cadavers using and individualized 3D printing guide. The intervertebral foramen (IVF) area was divided into entrance, middle, and exit zones and the trajectory angle was calculated from the computed tomography data. Results: Trans-iliac foraminotomy with an endoscope through the iliac hole using a 3D printed guide provide good visual access to the L7-S1 region. The variations in IVF in three zones were not significantly different after surgery. The angle of deviation of the guide was not significantly different caudally or ventrally after surgery. The mean trajectory angle after surgery was 14.06 ± 4.61°caudally and 13.07 ± 6.79° ventrally. Conclusions and Relevance: Our results suggest that surgical site were directly visualized during foraminotomy by the lateral approach through the spinal endoscope. However, other procedure including corpectomy and discectomy were not performed in this study.