Abstract
Background Context
Spinal deformities are very challenging to treat and have a great risk of neurologic
complications because of hardware placement during corrective surgery. Various techniques
have been introduced to ensure safe and accurate placement of pedicle screws. Patient-specific
screw guides with predrawn and prevalidated trajectory seem to be an attractive option.
Purpose
We have focused on developing three-dimensional (3D) printing technique for complex
spinal deformities in India. This study also aimed to compare the placement of pedicle
screw with 3D printing and freehand technique.
Study Design/Settings
This is a retrospective comparative clinical study in an academic institutional setting.
Patient Sample
A total of 20 patients were enrolled during the study: 10 were operated on with the
help of 3D printing (Group 1) and 10 were operated on with freehand technique (Group
2). Group 1 included six patients with congenital scoliosis, three patients with adolescent
idiopathic scoliosis (AIS), and one patient with post-tubercular kyphosis, and Group
2 included five patients with congenital scoliosis, four patients with AIS, and one
patient with post-tubercular kyphosis.
Outcome Measures
Primary outcomes were measured in terms of screw violation, and secondary outcomes
were measured in terms of surgical time, blood loss, radiation exposure (number of
shoots required), and complications.
Materials and Methods
MIMICS Base v18.0 software was used for 3D reconstruction from computed tomography
scan images of all the patients. 3-Matic software was used to create a drill guide.
A 3D printer from Stratasys Mojo with ABS P430 model material cartilage (a thermoplastic
material) was used for the printing of the vertebra model and jigs. A two-sample test
of proportion was used to compare correctly and wrongly placed pedicle screws with
3D printing and freehand technique. t Test with equal variance was used for operating surgical time and blood loss.
Results
No superior or inferior screw violation was observed in any of our patients in either
group. We found a significant difference (p=.03) between the two groups regarding
perfect screw placement in favor of 3D printing. There were 13 Grade 2 medial perforations
in the freehand group and 3 in the 3D printing group. There was no Grade 3 medial
perforation in either group. Six Grade 2 lateral perforations in the freehand group
and seven in the 3D printing group were observed. Three Grade 3 lateral perforations
in the freehand group and two in 3D printing group were observed. Analysis showed
a statistically significant (p=.005) medial violation in the freehand group. Surgical
time was significantly less (p=.03) in the 3D printing group compared with the freehand
group. Mean blood loss was higher in the freehand group but was not statistically
significant (p=.3) in the 3D printing group. Fluoroscopic shots required were less
in number in the 3D printing group compared with the freehand group. There was no
neurologic deficit in any of the patients in the two groups.
Conclusions
In our study, focusing on spinal deformities with statistically significant higher
rates of accurate screw positioning and higher numbers of inserted screws with 3D
printing was possible because of enhanced safety, particularly at apical levels. As
such, spinal deformities are difficult to treat worldwide. In India, these deformities
are often neglected and present at a very late and a much more deformed state when
their treatment becomes even more challenging. Developing these patient-specific drill
templates will enable an average spine surgeon to treat these patients with much ease
and safety.
Keywords
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References
- Rates and causes of mortality associated with spine surgery based on 108,419 procedures: a review of the Scoliosis Research Society Morbidity and Mortality Database.Spine. 2012; 37: 1975-1982
- Neurological complications in adult spinal deformity surgery.Curr Rev Musculoskelet Med. 2016; 9: 290-298
- Complications associated with thoracic pedicle screws in spinal deformity.Eur Spine J. 2010; 19: 1576-1584
- Techniques and accuracy of thoracolumbar pedicle screw placement.World J Orthop. 2014; 5: 112-123
- Accuracy and efficacy of thoracic pedicle screws in scoliosis with patient-specific drill template.Med Biol Eng Comput. 2012; 50: 751-758
- Efficacy and accuracy of a novel rapid prototyping drill template for cervical pedicle screw placement.Comput Aided Surg. 2011; 16: 240-248
- A novel patient-specific navigational template for cervical pedicle screw placement.Spine. 2009; 34: E959-E966
- A novel computer-assisted drill guide template for placement of C2 laminar screws.Eur Spine J. 2009; 18: 1379-1385
- A novel computer-assisted drill guide template for thoracic pedicle screw placement: a cadaveric study.Arch Orthop Trauma Surg. 2012; 132: 65-72
Article info
Publication history
Published online: May 03, 2018
Accepted:
May 1,
2018
Received in revised form:
April 4,
2018
Received:
January 23,
2018
Footnotes
FDA device/drug status: Not applicable.
Author disclosures: BG: Grant: DBT, Government of India (E, Paid directly to institution); Support for travel to meetings for the study or other purposes (B, Paid directly to institution), pertaining to the submitted manuscript. MG: Grant: DBT, Government of India (E, Paid directly to institution), pertaining to the submitted manuscript. MS: Grant: DBT, Government of India (E, Paid directly to institution), pertaining to the submitted manuscript. DK: Nothing to disclose.
The disclosure key can be found on the Table of Contents and at www.TheSpineJournalOnline.com.
This work was carried out by the collaboration of the Department of Orthopaedics of All India Institute of Medical Sciences, New Delhi, and the Department of Biomedical Engineering of Indian Institute of Technology, Delhi. This project received a grant of US$60,000 from Department of Biotechnology (DBT), Government of India, under the DBT Innovative Young Biotechnologist Award. No study-specific conflict of interest-associated biases were declared by the authors.
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