Surgical simulation of circumferential osteotomy and correction of cervico-thoracic kyphoscoliosis for an irreducible old C6-C7 fracture dislocation

Cervicothoracic dislocation due to congenital and bone-dysplasia-related vertebral malformations

PURPOSE

To evaluate the approaches to treatment of congenital and bone-dysplasia-related pediatric cervicothoracic dislocations and define the optimal treatment method.

METHODS

The publications available in PubMed and Google Scholar data bases were selected following such criteria as the disease in question, pediatric age, the treatment description, and follow-up results. The paper also includes the descriptions of our own six cases of the cervicothoracic dislocations detected in children with different vertebral malformations.

RESULTS

Only eight patients meeting the abovementioned selection criteria were found in the publications: three of them had the Klippel-Feil syndrome (KFS), two had one-level vertebral anomaly, one had neurofibromatosis (NF type 1), one had the Larsen syndrome, and one had a variation of VACTERL association. Their treatment was long term, multi stage, and complicated. Among six our own cases, four patients also had KFS, one had a variation of VACTERL association, and one had NF type 1. All the patients suffered from preoperative neurological disorders. Posterior instrumental fixation with posterior vertebral body resection was performed in four cases and one patient underwent a combined surgery. The parents of one of the patients refused the operation, so he was observed while receiving bracing treatment. Since the treatment was long term and complicated by reoperations, the average follow-up period comprised 5 years.

CONCLUSION

Congenital cervicothoracic dislocations are an extremely rare pathology that manifests itself in early age and requires an early surgical treatment. Failure to provide the treatment leads to the patient's disability. The surgical tactics for such patients is determined individually, but the published data and our own experience demonstrate that early multi-stage combined treatment has been the best option available so far. The cervicothoracic dislocations due to NF 1 manifest later and have a more favorable forecast.

Severe, rigid cervical kyphotic deformity associated with SAPHO syndrome successfully treated with three-stage correction surgery combined with C7 vertebral column resection: a technical case report

STUDY DESIGN

Case report.

OBJECTIVES

To describe the first reported use of corrective surgery combined with C7 vertebral column resection (VCR) to treat an extremely rare case of severe, rigid cervical kyphotic deformity associated with synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome.

BACKGROUND DATA

Spinal lesions reportedly occur in 32-45% in SAPHO syndrome. However, bone and joint lesions are usually repaired such that severe joint destruction is rare. Therefore, there have been few reported cases of surgical treatment for spinal lesions.

METHODS

A 22-year-old woman had been diagnosed with cervical kyphotic deformity associated with SAPHO syndrome. She had difficulty looking upward. On radiography, the C4-C7 vertebral bodies were fused and exhibited severe rigid kyphotic deformity. Right convex scoliosis with a Cobb angle of 22° was apparent at C5-T2, and the C2-C7 angle of kyphosis was 75°. Corrective three-stage surgery was carried out from the anterior, posterior, and anterior, with C7 VCR.

RESULTS

The C2-T1 angle improved to 21° and the patient was capable of looking up. At present, 2 years postoperatively, complete bony fusion has been achieved. Her cervical spine function and quality of life were markedly improved.

CONCLUSION

Only a very limited number of patients have a deformity sufficiently severe that VCR of cervical vertebra is required, but as this is the technique that provides the greatest multiplanar alignment correction, its choice in the present case was appropriate.

LEVEL OF EVIDENCE

IV.

3D printing in shoulder surgery

Three-dimensional (3D) printing is a novel modality with the potential to make a huge impact in the surgical field. The aim of this paper is to provide an overview on the current use of 3D printing in shoulder surgery. We have reviewed the use of this new method in 3 fields of shoulder surgery: shoulder arthroplasty, recurrent shoulder instability and orthopedic shoulder traumatology. In shoulder arthroplasty, several authors have shown that the use of the 3D printer improves the positioning of the glenoid component, even if longer clinical follow-up is needed to determine whether the cost of this system rationalizes the potential improved functional outcomes and decreases glenoid revision rates. In the treatment of anterior shoulder instability, the literature agrees on the fact that the use of the 3D printing can: enhance the dept and size of bony lesions, allowing a patient tailored surgical planning and potentially reducing operative times; allow the production of personalized implants to restore substantial bone loss; restore glenohumeral morphology and instability. In orthopedic trauma, the use of 3D printing can be helpful to increase the understanding of fracture patterns, facilitating a more personalized planning, and can be used for resident training and education. We can conclude the current literature regarding the use of 3D printed models in orthopedic surgery agrees finding objective improvements to preoperative planning and to the surgical procedure itself, by shortening the intraoperative time and by the possibility to develop custom-made, patient-specific surgical instruments, and it suggests that there are tangible benefits for its implementation.

Simultaneously Combined Anterior-Posterior Approaches for Subaxial Cervical Circumferential Reconstruction in a Sitting Position

The purpose of this article is to introduce and analyze the feasibility of simultaneously combined anterior-posterior approaches for subaxial cervical circumferential reconstruction in sitting position. A retrospective case review was performed for above surgery procedure. A 79-year-old man was confirmed subaxial cervical fracture and dislocation with facet locked by radiological examination, and the involved levels were C5-6. According to American Spinal Injury Association (ASIA) classification, the impairment scale was grade B. And the Subaxial Cervical Spine Injury and Severity Score (SLIC) were 9. The patient was restricted in sitting position with traction on a halo in extension to immobilize the head during the operation. A posterior laminectomy and pedicle screws insertion to the involved cervical spine was performed firstly. And then the anterior discectomy and strut graft were accomplished through an anterior cervical approach. The final fixation was finished by clamping the strut graft with pedicle screw system. Total blood loss was 600 ml and the total operating time was 150 min. The patient was followed up for 6 months. The symptom of neck pain improved distinctly and no evidence about implant failure was noted. Neurological status improvement was confirmed and the ASIA scale was improved to grade C. We believed that the simultaneously combined anterior-posterior approach in sitting position was safe and more advantageous for appropriate cases.

Three-dimensional Physical Modeling: Applications and Experience at Mayo Clinic

Radiologists will be at the center of the rapid technologic expansion of three-dimensional (3D) printing of medical models, as accurate models depend on well-planned, high-quality imaging studies. This article outlines the available technology and the processes necessary to create 3D models from the radiologist's perspective. We review the published medical literature regarding the use of 3D models in various surgical practices and share our experience in creating a hospital-based three-dimensional printing laboratory to aid in the planning of complex surgeries.

The residual STL volume as a metric to evaluate accuracy and reproducibility of anatomic models for 3D printing: application in the validation of 3D-printable models of maxillofacial bone from reduced radiation dose CT images

Background

The effects of reduced radiation dose CT for the generation of maxillofacial bone STL models for 3D printing is currently unknown. Images of two full-face transplantation patients scanned with non-contrast 320-detector row CT were reconstructed at fractions of the acquisition radiation dose using noise simulation software and both filtered back-projection (FBP) and Adaptive Iterative Dose Reduction 3D (AIDR3D). The maxillofacial bone STL model segmented with thresholding from AIDR3D images at 100 % dose was considered the reference. For all other dose/reconstruction method combinations, a “residual STL volume” was calculated as the topologic subtraction of the STL model derived from that dataset from the reference and correlated to radiation dose.

Results

The residual volume decreased with increasing radiation dose and was lower for AIDR3D compared to FBP reconstructions at all doses. As a fraction of the reference STL volume, the residual volume decreased from 2.9 % (20 % dose) to 1.4 % (50 % dose) in patient 1, and from 4.1 % to 1.9 %, respectively in patient 2 for AIDR3D reconstructions. For FBP reconstructions it decreased from 3.3 % (20 % dose) to 1.0 % (100 % dose) in patient 1, and from 5.5 % to 1.6 %, respectively in patient 2. Its morphology resembled a thin shell on the osseous surface with average thickness <0.1 mm.

Conclusion

The residual volume, a topological difference metric of STL models of tissue depicted in DICOM images supports that reduction of CT dose by up to 80 % of the clinical acquisition in conjunction with iterative reconstruction yields maxillofacial bone models accurate for 3D printing.

Novel approach for the efficient use of a full-scale, 3-dimensional model for cervical posterior fixation: a technical case report

STUDY DESIGN

Case report of a patient with atlantoaxial subluxation who underwent posterior cervical fixation.

OBJECTIVE

To describe a novel approach for the efficient use of a full-scale, 3-dimensional model for preoperative planning and surgery.

SUMMARY OF BACKGROUND DATA

Instrumented fusion of the cervical spine with screws and rods is indicated for atlantoaxial subluxation. Fatal complications, such as vertebral artery and spinal cord injuries, may occur during screw insertion. Making appropriate connecting rods, after screw insertion, is often time consuming. Therefore, precise preoperative planning and careful intraoperative procedures are required.

METHODS

A 73-year-old male with atlantoaxial subluxation presented with progressive quadriplegia and gait disturbance. Surgery involving a C1 laminectomy and posterior cervical fixation was planned; and a 3D model, allowing visualization of the vertebral artery, was developed. Bilateral C1 and C4 lateral mass screws and C2 pars screws were experimentally inserted into the model. Rods with appropriate curvature were created to obtain rigid screw fixation, and were used during the surgery. Moreover, radiography and computed tomographic images of the instrumented model were analyzed to ensure the proper orientation of the screws.

RESULTS

During surgery, screw insertion was performed, under fluoroscopic guidance, and compared with the 3D model and its preoperative radiographs. According to the preoperative analysis of the model-computed tomographic images, the direction of the C1 lateral mass screws was changed laterally, and the lengths of the C2 pars screws were shortened to avoid complications. The sterile, prebent rods could be elegantly adapted to the screws without additional bending. The postoperative course was uneventful, and postoperative computed tomographic images showed proper screw positioning.

CONCLUSION

Three-dimensional models that allow (1) visualization of the vertebral artery, (2) evaluation of radiological images after screw insertion, and (3) the use of prebent rods during surgery contribute to the safety of the cervical posterior fixation.

LEVEL OF EVIDENCE

N/A.