Accuracy and Efficacy of a Patient-Specific Drill Guide Template System for Lumbosacral Junction Fixation in Medium and Small Dogs: Cadaveric Study and Clinical Cases.

Toru Fujioka,Sadatoshi Maeda,Taku Sugawara,Yuta Nozue,Kohei Nakata,Yukiko Nakano,Naoyuki Konno,Hiroaki Kamishina

doi:10.3389/fvets.2019.00494

Abstract

Objectives: To develop drill guide templates as an intraoperative guide, and to evaluate the accuracy and safety of screw placement in the lumbosacral junction.Samples: Canine cadaveric specimens of the lumbosacral junction (n = 6), and clinical cases of lumbosacral instability (n = 3).Procedures: Computed tomography data of the lumbosacral region of cadaveric specimens and clinical cases were obtained. The optimum screw trajectories were determined and drill guide templates were fabricated using a three-dimensional printing system. Drill holes were made using the templates in cadaveric specimens and clinical cases, and lumbosacral fixation was performed in clinical cases. Computed tomography images were obtained to compare the planned and postoperative drill hole trajectories, and the accuracy and safety of drilling and screw placement in the lumbosacral junction were evaluated.Results: Thirty-six drill holes were made in cadaveric specimens. The overall mean drill hole deviation was 2.05 ± 1.32 mm. A total of 12 screws were placed in the lumbosacral junctions of three clinical cases. The overall mean drill hole deviation was 2.43 ± 1.09 mm. Clinical signs improved within 2 weeks in the clinical cases. All drill holes were completely located within the bone in cadaveric specimens and clinical cases.Conclusion and Clinical Relevance: The surgical procedures using the drill guide templates were performed safely with good clinical outcomes. The drill guide template system provided useful surgical guidance to safely and precisely perform screw placement for lumbosacral fixation surgery in small dogs.

Highlights

IntroductionLumbosacral luxation in dogs caused by degenerative lumbosacral stenosis (DLSS), trauma (fracture and/or luxation), discospondylitis, neoplasia
Lumbosacral luxation in dogs caused by degenerative lumbosacral stenosis (DLSS), trauma, discospondylitis, neoplasia
The reported surgical techniques for DLSS include dorsal laminectomy alone or in combination with partial discectomy, dorsal laminectomy combined with fixation and fusion, or lateral foraminotomy [2, 3, 5,6,7,8]

Summary

Introduction

Lumbosacral luxation in dogs caused by degenerative lumbosacral stenosis (DLSS), trauma (fracture and/or luxation), discospondylitis, neoplasia. DLSS is characterized by stenosis of the spinal canal, causing compression of the cauda equina in dogs. This condition is most commonly seen in medium- and large-sized dogs, it can be seen in small dogs, typically presenting with caudal lumbar back pain [1]. Decompressive surgery alone could further aggravate instability of the lumbosacral junction, and dorsal vertebral body fixation should be considered in cases with a high risk of postoperative instability at the surgical site [4, 7, 9]

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Conclusion