Vet Comp Orthop Traumatol 2021; 34(05): 338-345
DOI: 10.1055/s-0041-1731808
Original Research

Accuracy and Safety of Image-Guided Freehand Pin Placement in Canine Cadaveric Vertebrae

1   Department of Clinical Veterinary Medicine, Division of Clinical Neurology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
2   Department of Clinical Veterinary Medicine, Division of Small Animal Surgery, Vetsuisse Faculty, University of Bern, Bern, Switzerland
Justus M.K. Rathmann
3   Institute of Sociology, University of Zurich, Zurich, Switzerland
Veronika M. Stein
1   Department of Clinical Veterinary Medicine, Division of Clinical Neurology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
Christina M. Precht
4   Department of Clinical Veterinary Medicine, Division of Clinical Radiology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
1   Department of Clinical Veterinary Medicine, Division of Clinical Neurology, Vetsuisse Faculty, University of Bern, Bern, Switzerland
› Author Affiliations


Objective The aim of this study was to validate an imaging technique for evaluation of spinal surgery accuracy and to establish accuracy and safety of freehand technique in the thoracolumbar spine of large breed dogs.

Study Design After thoracolumbar spine computed tomography (CT), 26 drilling corridors were planned then drilled to receive 3.2 mm positive profile pins using a freehand technique. After pin removal, CT was repeated. All entry points, exit points and angles of the preoperative planned trajectories were compared with postoperative ones using an image registration and fusion technique by three observers. Corridor coordinates for entry and exit points were evaluated in three dimensions and angles were measured in one plane. Intraclass correlation coefficient (ICC) was used to establish the imaging technique reliability and descriptive statistics were used to report on the freehand technique accuracy. Safety was evaluated using a vertebral cortical breach grading scheme.

Results Intraclass correlation coefficient for the entry points, exit points and angle were 0.79, 0.96 and 0.92 respectively. Mean deviations for the entry points, exit points and angle were 3.1 mm, 6.3 mm and 7.6 degrees respectively. Maximum deviations were 6.3 mm, 11.0 mm and 16.4 degrees. Most deviations were lateral and caudal. All corridors were judged as safe.

Conclusion The imaging technique reliability was good to excellent to study spinal surgery accuracy. Implant deviations should be anticipated when planning stabilization surgery in large breed dogs using the freehand-guided technique.

Authors' Contributions

J.G. and E.S. executed the experiments and registered the data. J.R. did statistical analysis. J.G., E.S., F.F., J.R., C.P. and V.S. interpreted and critically revised the manuscript for important intellectual contribution. All the authors approved the final version.

Publication History

Received: 29 September 2020

Accepted: 08 June 2021

Article published online:
23 July 2021

© 2021. Thieme. All rights reserved.

Georg Thieme Verlag KG
Rüdigerstraße 14, 70469 Stuttgart, Germany

  • References

  • 1 Johnston SA, Tobias KM. Veterinary Surgery: Small Animal. 2nd ed. St. Louis: Elsevier; 2018: 487-503
  • 2 Aikawa T, Kanazono S, Yoshigae Y, Sharp NJH, Muñana KR. Vertebral stabilization using positively threaded profile pins and polymethylmethacrylate, with or without laminectomy, for spinal canal stenosis and vertebral instability caused by congenital thoracic vertebral anomalies. Vet Surg 2007; 36 (05) 432-441
  • 3 Blass CE, Seim III HB. Spinal fixation in dogs using Steinmann pins and methylmethacrylate. Vet Surg 1984; 13 (04) 203-210
  • 4 Worth A, Meij B, Jeffery N. Canine degenerative lumbosacral stenosis: prevalence, impact and management strategies. Vet Med (Auckl) 2019; 10: 169-183
  • 5 Jeffery ND. Vertebral fracture and luxation in small animals. Vet Clin North Am Small Anim Pract 2010; 40 (05) 809-828
  • 6 Sturges BK, Kapatkin AS, Garcia TC. et al. Biomechanical comparison of locking compression plate versus positive profile pins and polymethylmethacrylate for stabilization of the canine lumbar vertebrae. Vet Surg 2016; 45 (03) 309-318
  • 7 Fujioka T, Nakata K, Nishida H. et al. A novel patient-specific drill guide template for stabilization of thoracolumbar vertebrae of dogs: cadaveric study and clinical cases. Vet Surg 2019; 48 (03) 336-342
  • 8 Gonnet A. AO principles of fracture management in the dog and cat. . Schweiz Arch Tierheilkd 2006; 148: 319
  • 9 Steffen F, Voss K, Morgan JP. Distraction-fusion for caudal cervical spondylomyelopathy using an intervertebral cage and locking plates in 14 dogs. Vet Surg 2011; 40 (06) 743-752
  • 10 Hall DA, Snelling SR, Ackland DC, Wu W, Morton JM. Bending strength and stiffness of canine cadaver spines after fixation of a lumbar spinal fracture-luxation using a novel unilateral stabilization technique compared to traditional dorsal stabilization. Vet Surg 2015; 44 (01) 94-102
  • 11 Tran JH, Hall DA, Morton JM, Deruddere KJ, Snelling SR. Accuracy and safety of pin placement during lateral versus dorsal stabilization of lumbar spinal fracture-luxation in dogs. Vet Surg 2017; 46 (08) 1166-1174
  • 12 Trotter EJ. Cervical spine locking plate fixation for treatment of cervical spondylotic myelopathy in large breed dogs. Vet Surg 2009; 38 (06) 705-718
  • 13 Bagley RS. Spinal neoplasms in small animals. Vet Clin North Am Small Anim Pract 2010; 40 (05) 915-927
  • 14 Dernell WS, Van Vechten BJ, Straw RC, LaRue SM, Powers BE, Withrow SJ. Outcome following treatment of vertebral tumors in 20 dogs (1986-1995). J Am Anim Hosp Assoc 2000; 36 (03) 245-251
  • 15 Tellegen AR, Willems N, Tryfonidou MA, Meij BP. Pedicle screw-rod fixation: a feasible treatment for dogs with severe degenerative lumbosacral stenosis. BMC Vet Res 2015; 11: 299
  • 16 Auger J, Dupuis J, Quesnel A, Beauregard G. Surgical treatment of lumbosacral instability caused by discospondylitis in four dogs. Vet Surg 2000; 29 (01) 70-80
  • 17 Watine S, Cabassu JP, Catheland S, Brochier L, Ivanoff S. Computed tomography study of implantation corridors in canine vertebrae. J Small Anim Pract 2006; 47 (11) 651-657
  • 18 Wheeler JL, Cross AR, Rapoff AJ. A comparison of the accuracy and safety of vertebral body pin placement using a fluoroscopically guided versus an open surgical approach: an in vitro study. Vet Surg 2002; 31 (05) 468-474
  • 19 Wheeler JL, Lewis DD, Cross AR, Sereda CW. Closed fluoroscopic-assisted spinal arch external skeletal fixation for the stabilization of vertebral column injuries in five dogs. Vet Surg 2007; 36 (05) 442-448
  • 20 Hamilton-Bennett SE, Oxley B, Behr S. Accuracy of a patient-specific 3D printed drill guide for placement of cervical transpedicular screws. Vet Surg 2018; 47 (02) 236-242
  • 21 Guevar J, Bleedorn J, Cullum T, Hetzel S, Zlotnick J, Mariani C. Accuracy and safety of three-dimensionally printed animal-specific drill guides for thoracolumbar vertebral column instrumentation in dogs: bilateral and unilateral designs. Vet Surg 2021; 50 (02) 336-344
  • 22 Gelalis ID, Paschos NK, Pakos EE. et al. Accuracy of pedicle screw placement: a systematic review of prospective in vivo studies comparing free hand, fluoroscopy guidance and navigation techniques. Eur Spine J 2012; 21 (02) 247-255
  • 23 Rahmathulla G, Nottmeier EW, Pirris SM, Deen HG, Pichelmann MA. Intraoperative image-guided spinal navigation: technical pitfalls and their avoidance. Neurosurg Focus 2014; 36 (03) E3
  • 24 Puvanesarajah V, Liauw JA, Lo SF, Lina IA, Witham TF. Techniques and accuracy of thoracolumbar pedicle screw placement. World J Orthop 2014; 5 (02) 112-123
  • 25 Smolders LA, Voorhout G, van de Ven R. et al. Pedicle screw-rod fixation of the canine lumbosacral junction. Vet Surg 2012; 41 (06) 720-732
  • 26 Gao S, Lv Z, Fang H. Robot-assisted and conventional freehand pedicle screw placement: a systematic review and meta-analysis of randomized controlled trials. Eur Spine J 2018; 27 (04) 921-930
  • 27 Ranganathan P, Pramesh CS, Aggarwal R. Common pitfalls in statistical analysis: Measures of agreement. Perspect Clin Res 2017; 8 (04) 187-191
  • 28 Koo TK, Li MY. A guideline of selecting and reporting intraclass correlation coefficients for reliability research. J Chiropr Med 2016; 15 (02) 155-163
  • 29 Santoni BG, Hynes RA, McGilvray KC. et al. Cortical bone trajectory for lumbar pedicle screws. Spine J 2009; 9 (05) 366-373