Computer-Based 3D Simulations to Formulate Preoperative Planning of Bridge Crane Technique for Thoracic Ossification of the Ligamentum Flavum

Abstract

BackgroundThe bridge crane technique is a novel surgical technique for the treatment of thoracic ossification of the ligamentum flavum (TOLF), but its preoperative planning has not been studied well, which limits the safety and efficacy of surgery to some extent. The purpose of this study was to investigate the method of application and effect of computer-aided preoperative planning (CAPP) on the bridge crane technique for TOLF.Material/MethodsThis retrospective multi-center included 40 patients with TOLF who underwent the bridge crane technique from 2016 to 2018. According to the utilization of CAPP, patients were divided into Group A (with CAPP, n=21) and Group B (without CAPP, n=19). Comparisons of clinical and radiological outcomes were carried out between the 2 groups.ResultsThe patients in Group A had higher post-mJOA scores and IR of neurological function than those in Group B (p<0.05). Group A had shorter surgery time, fewer fluoroscopic images, and lower incidence of complications than Group B. In Group A, there was a high consistency of all the anatomical parameters between preoperative simulation and postoperative CT (p>0.05). In Group B, there were significant differences in 3 anatomical parameters between postoperative simulation and postoperative CT (p<0.05). In Group B, the patients with no complications had higher post-SVOR and lower SVRR and height of posterior suspension of LOC in postoperative CT than those in postoperative simulation (p<0.05).ConclusionsCAPP can enable surgeons to control the decompression effect accurately and reduce the risk of related complications, which improves the safety and efficacy of surgery.

The clinical value of three-dimensional measurement in the diagnosis of thoracic myelopathy caused by ossification of the ligamentum flavum

“…After filtering patients using these criteria, 173 patients were excluded and 81 were finally enrolled as the myelopathy group (Figure 1). Neurological function was assessed on the basis of a modified Japanese Orthopedic Association (mJOA) scoring system for thoracic myelopathy (Table 1) (8).…”

“…However, these conventional radiological parameters may not provide sufficient information to determine the responsible segment, because thoracic OLF is a three-dimensional (3D) disease, as opposed to a 1D or 2D disease (7). Recent studies have displayed a new technique to measure the ossification volume based on 3D reconstruction from computed tomography (CT) images (7)(8)(9). In this study, we sought to analyze 3D radiological parameters in order to establish a novel diagnostic method for discriminating the responsible segment in OLFinduced thoracic myelopathy, and to evaluate its superiority compared to the conventional diagnostic methods.…”

“…Lastly, the 3D reconstruction technique based on the Mimics software has been applied to various clinical aspects, including computerassisted virtual operation planning, personalized 3D printing treatment, and accurate measurement of parameters. Many previous studies also showed particular advantages of the 3D reconstruction technique compared with conventional methods, including more detailed and accurate preoperative information, fewer surgical complications, less blood loss, a shorter operation time, and fewer fluoroscopic images (7,8,23,(29)(30)(31)(32). However, 3D model reconstruction still requires more time and effort compared to the 1D or 2D measurement methods.…”

Letter to Editor on “The Gantry Crane Technique: A Novel Technique for Treating Severe Thoracic Spinal Stenosis and Myelopathy Caused by Ossification of the Ligamentum Flavum and Preliminary Clinical Results” by Jian Zhu et al

“…However, Sun J et al 2 reported the analogous bridge crane technique, in which they explained that a sufficient elevation height was 10.3 mm to treat severe thoracic spinal stenosis and myelopathy. Yan C et al 3 reported using computer-based 3D simulations to formulate preoperative planning of bridge crane technique for thoracic ossification of the ligamentum flavum (TOLF). The posterior elevation height of LOC was about 7 mm.…”