Mizoribine Promotes Molecular Chaperone HSP60/HSP10 Complex Formation.

It has been reported that Mizoribine is an immunosuppressant used to suppress rejection in renal transplantation, nephrotic syndrome, lupus nephritis, and rheumatoid arthritis. The molecular chaperone HSP60 alone induces inflammatory cytokine IL-6 and the co-chaperone HSP10 alone inhibits IL-6 induction. HSP60 and HSP10 form a complex in the presence of ATP. We analyzed the effects of Mizoribine, which is structurally similar to ATP, on the structure and physiological functions of HSP60-HSP10 using Native/PAGE and transmission electron microscopy. At low concentrations of Mizoribine, no complex formation of HSP60-HSP10 was observed, nor was the expression of IL-6 affected. On the other hand, high concentrations of Mizoribine promoted HSP60-HSP10 complex formation and consequently suppressed IL-6 expression. Here, we propose a novel mechanism of immunosuppressive action of Mizoribine.

Cervical myelopathy due to neurovascular compression syndrome caused by persistent first intersegmental artery: a case report.

BACKGROUND: Persistent first intersegmental artery (PFIA) is a rare anatomical variation of vertebral arteries and is an asymptomatic finding in most cases. Here we report a rare case of cervical myelopathy caused by spinal cord compression by the PFIA. CASE PRESENTATION: The patient was a 52-year-old man who complained of numbness and burning sensation around the neck and left shoulder area, partial weakness in the left deltoid muscle, right side thermal hypoalgesia, and disturbance of deep sensation since the past 1 year, and the symptoms had gradually worsened. Magnetic resonance imaging (MRI) and computed tomography (CT) showed spinal cord compression by the left PFIA at the C1/C2 level. Because conservative treatment was ineffective, microvascular decompression (MVD) of the PFIA was performed. The left PFIA was laterally transposed using polytetrafluoroethylene (PTFE) bands and anchored to the dura mater using three PTFE bands. To achieve adequate transposition, the small blood vessels bridging the spinal cord and PFIA and the dorsal root nerve had to be sacrificed. Postoperative T2-weighted MRI showed a small hyperintense region in the lateral funiculus of the spinal cord, but no new neurological deficits were identified. In the early postoperative stage, the patient's deep sensory impairment and motor dysfunction were improved. His numbness and burning sensation almost disappeared, but slight thermal hypoalgesia remained in the lower limb. CONCLUSION: MVD is an effective treatment for spinal cord compression caused by the PFIA, but further studies are necessary to help address technical difficulties and avoid complications.

A novel patient-specific drill guide template for stabilization of thoracolumbar vertebrae of dogs: cadaveric study and clinical cases.

OBJECTIVE: To evaluate the accuracy and safety of a novel patient-specific drill guide template for stabilizing the thoracolumbar vertebrae of dogs. STUDY DESIGN: Cadaveric experimental study and prospective case series. SAMPLE POPULATION: Cadaveric canine thoracolumbar vertebral specimens (n = 3) and clinical cases of thoracolumbar spinal instability (n = 4). METHODS: Computed tomography data of the thoracolumbar spines were obtained before surgery, and images were imported into imaging software. Optimum screw trajectories were selected for each vertebra, and drill guide templates were designed and fabricated with a 3-dimensional printing system. Drill guide templates were applied to cadaveric spine and clinical cases. Computed tomography imaging was performed after surgery, and planned and postoperative trajectories were compared to estimate the accuracy and safety of the drill guide templates. RESULTS: Twenty-two drill holes were made in cadaveric spinal specimens. All drill holes were completely located in the bone. The overall mean screw deviation was 0.88 ± 0.36 mm. In clinical cases, 29 screws were placed in thoracolumbar vertebrae. Most (89.6%) of these screws were placed without evidence of vertebral canal invasion. One (3.5%) screw perforated the bone structure. The overall mean screw deviation was 1.16 ± 0.56 mm. CONCLUSION: Drill guide templates were useful for accurate intraoperative screw navigation in thoracolumbar fixation in small dogs. CLINICAL SIGNIFICANCE: The use of drill guide templates can be considered as an aid to safety and accuracy of screw placement in canine thoracolumbar instabilities.

Assessing the Accuracy and Safety Thresholds of Patient-Specific Screw Guide Template System in Cervical and Thoracic Spine Surgeries Using DAST Measurements.

Introduction: To analyze the reliability of the newly developed patient-specific Screw Guide Template (SGT) system as an intraoperative navigation device for spinal screw insertion. Methods: We attempted to place 428 screws for 51 patients. The accuracy of the screw track was assessed by deviation of the screw axis from the preplanned trajectory on postoperative CT. The safety of the screw insertion was evaluated by the bone breach of the screw. The bone diameter available for screw trajectory (DAST) was measured, and the relations to the bone breach were analyzed. Results: In the inserted screws, 98.4% were defined as accurate, and 94.6% were contained in the target bone. In the cervical spine, the screw deviation between breaching (0.57 mm) and contained screws (0.43 mm) did not significantly differ, whereas DAST for breaching screws (3.62 mm) was significantly smaller than contained screws (5.33 mm) (p<0.001). Cervical screws with ≥4.0 mm DAST showed a significantly lower incidence of bone breach (0.4%) than ≤3.9 mm DAST (28.3%) (p<0.001). In the thoracic spine, screw deviation and DAST had significant differences between breaching (1.54 mm, 4.41 mm) and contained (0.75 mm, 6.07 mm) (p<0.001). The incidence of the breach was significantly lower in thoracic screws with ≥5.0 mm (1.9%) than ≤4.9 (21.9%) DAST (p<0.001). Conclusions: This study demonstrated that our SGT system could support precise screw insertion for 98.4% accuracy and 94.6% safety. DAST was recommended to be ≥4.0 and ≥5.0 mm in the cervical and thoracic spines for safe screw insertion.

Latent Toehold-Mediated DNA Circuits Based on a Bulge-Loop Structure for Leakage Reduction and Its Application to Signal-Amplifying DNA Logic Gates.

DNA circuits based on successive toehold-mediated DNA displacement reactions, particularly entropy-driven DNA circuit (EDC) systems, have attracted considerable attention as powerful enzyme-free tools for dynamic DNA nanotechnology. However, background leakage (noise signal) often occurs when the circuit is executed nonspecifically, even in the absence of the appropriate catalyst DNA (input). This study designed and developed a new latent toehold-mediated DNA circuit (LDC) system that relies on a bulge-loop structure as a latent toehold toward leakage reduction. Furthermore, the number (size) of nucleotides (nt) in the bulge-loop is found to play a significant role in the performance (i.e., leakage, signal, and kinetics) of LDC systems. In fact, the signal rate for the LDC systems increased as the number of nt in the bulge-loop increased from 4 to 8, whereas the leakage rate of the LDC systems with bulge-loops of 7 nt or less was low, but the leakage rate of the LDC system with a bulge-loop of 8 nt increased significantly. Note that the LDC system with the optimal bulge-loop (7 nt) was capable of not only reducing the leakage but also accelerating the circuit speed without any signal loss, unlike methods of reducing the leakage by reducing the signal reported previously for the conventional EDC systems. These facts indicate that the 7 nt bulge-loop acts as a "latent" toehold for the DNA circuit system. By using the amplification function of output signals with an accelerated circuit and reduced leakage, our LDC system with a 7 nt bulge-loop could be applied directly and successfully to signal-amplifying DNA logic gates such as OR and AND gates, and thus, sufficient output signals could be obtained even with a small amount of input. These findings reveal that our LDC systems with a bulge-loop structure can replace the conventional EDC system and have enormous potential in the field of DNA nanotechnology.

The components of the AhR-molecular chaperone complex differ depending on whether the ligands are toxic or non-toxic.

The aryl hydrocarbon receptor (AhR) forms a complex with the HSP90-XAP2-p23 molecular chaperone when the cells are exposed to toxic compounds. Recently, 1,4-dihydroxy-2-naphthoic acid (DHNA) was reported to be an AhR ligand. Here, we investigated the components of the molecular chaperone complex when DHNA binds to AhR. Proteins eluted from the 3-Methylcolanthrene-affinity column were AhR-HSP90-XAP2-p23 complex. The AhR-molecular chaperone complex did not contain p23 in the eluents from the DHNA-affinity column. In 3-MC-treated cells, AhR formed a complex with HSP90-XAP2-p23 and nuclear translocation occurred within 30 min, while in DHNA-treated cells, AhR formed a complex with AhR-HSP90-XAP2, and translocation was slow from 60 min. Thus, the AhR activation mechanism may differ when DHNA is the ligand compared to toxic ligands.

Efficacy of Spinal Cord Stimulation for Failed Back Surgery Syndrome in Elderly Patients: A Retrospective Study.

Objectives: Failed back surgery syndrome (FBSS) refers to a condition where symptoms such as low back pain, leg pain, and numbness persist or recur after lumbar surgery; it has been reported to occur in 10%-40% of patients who have undergone lumbar surgery. Spinal cord stimulation (SCS) has been reported useful for low back and leg pain due to FBSS. In this study, we studied the efficacy and safety of SCS for FBSS in older adults. Methods: Among FBSS patients who underwent an SCS trial between November 2017 and December 2020, those with at least 50% pain reduction during the trial phase who requested spinal cord stimulator implantation underwent implantation of a stimulator under local anesthesia. The patients were divided into two groups: patients aged <75 years (<75-year-old group) and patients aged ≥75 years (≥75-year-old group). The male/female ratio, symptom duration, operative duration, visual analog scale (VAS) scores before and after one year of surgery, responder rate (RR), complications one year after surgery, and stimulator removal rate were analyzed. Results: There were 27 cases in the <75-year-old group and 46 in the ≥75-year-old group, with no significant differences in male/female ratio, duration of pain, or operative time between the two groups. VAS scores for low back pain, leg pain, and overall pain one year after surgery were improved significantly from respective preoperative scores in both groups (P < 0.001). There were no significant differences in low back pain VAS, leg pain VAS, overall pain VAS, RR, complications one year after surgery, or stimulator removal rate between the two groups. Conclusion: SCS reduced pain effectively in both <75-year-old and ≥75-year-old groups with no differences in complications. Therefore, spinal cord stimulator implantation was considered a viable option for FBSS treatment in older adults because it can be performed under local anesthesia and is associated with a low incidence of complications.

Intramedullary Schwannoma of the Spinal Cord: A Nationwide Analysis by the Neurospinal Society of Japan.

OBJECTIVE: This study was aimed to report the clinical characteristics of intramedullary schwannomas and discuss imaging findings and treatment strategies. METHODS: The inclusion criterion was consecutive patients with intramedullary schwannomas who were surgically treated at 8 centers between 2009 and 2020. Clinical characteristics included age, sex, clinical presentation, disease duration, and follow-up period. The modified McCormick scale was used to compare the preoperative and postoperative conditions. Pre- and postoperative magnetic resonance images (MRI) of each case were analyzed. RESULTS: The mean age of the total 11 patients at the operation was 50.2 years. The mean duration of the symptoms was 23 months, with limb paresthesia being the most common clinical presentation. The cervical spine was the most common localization level of the tumor in 6 cases. The mean follow-up duration was 49.4 months. Gross total resection (GTR) and subtotal resection (STR) was achieved in 9 and 2 cases, respectively. According to the modified McCormick scale at 6 months postoperatively, 7 cases (63.6%) had improved and 4 cases (36.3%) had unchanged grades. Typical MRI findings of the intramedullary schwannoma included ring-like enhancement, syringomyelia, cystic formation, intramedullary edema, and hemosiderin deposition. Gadolinium enhancement was homogenous in 8 cases (72.7%). The tumor margins were well demarcated in all cases. CONCLUSION: Intramedullary schwannoma should be considered when sharp margins and well-enhanced tumors are present at the cervical spine level and the initial symptoms are relatively mild, such as dysesthesia. When GTR cannot be achieved, STR for tumor decompression is recommended.

Novel wrapping surgery for symptomatic sacral perineural cysts.

OBJECTIVE: Perineural cysts, also called Tarlov cysts, are dilatations of the nerve root sleeves commonly found in the sacrum. The majority of the cysts are asymptomatic and found incidentally on routine spine imaging. Symptomatic sacral perineural cysts (SPCs) that induce intractable low-back pain, radicular symptoms, and bladder/bowel dysfunction require surgery. However, the surgical strategy for symptomatic SPCs remains controversial. The authors hypothesized that the symptoms were caused by an irritation of the adjacent nerve roots caused by SPCs, and developed a wrapping surgery to treat these cysts. METHODS: Seven patients with severe unilateral medial thigh pain and ipsilateral SPCs were included. Preoperative MRI showed that the cysts were severely compressing the adjacent nerve roots in all patients. After a partial laminectomy of the sacrum, the SPCs were punctured and CSF was aspirated to reduce their size, followed by dissection of the adjacent nerve roots from the SPCs. The SPCs were then wrapped with a Gore-Tex membrane to avoid reexpansion. RESULTS: All 7 patients experienced substantial relief of their symptoms. The average numeric rating scale pain score was reduced from an average preoperative value of 7.9 to 0.6 postoperatively. Postoperative MRI showed that all cysts were reduced in size and the adjacent nerve roots were decompressed. Regrowth of the treated cysts or recurrence of the symptoms did not occur during the entire follow-up period, which ranged from 39 to 90 months. No complications were noted. CONCLUSIONS: The authors' new wrapping technique was effective in relieving radicular symptoms for patients with symptomatic SPCs. The results suggested that the symptoms stemmed from compression of the adjacent nerve roots caused by the SPCs, and not from the nerve roots in the cysts.

Safety and Validity of Anterior Cervical Disc Replacement for Single-level Cervical Disc Disease: Initial Two-year Follow-up of the Prospective Observational Post-marketing Surveillance Study for Japanese Patients.

Anterior cervical disc replacement (ACDR) using cervical artificial disc (CAD) has the advantage of maintaining the range of motion (ROM) at the surgical level, subsequently reducing the postoperative risk of adjacent disc disease. Following the approval for the clinical use in Japan, a post-marketing surveillance (PMS) study was conducted for two different types of CAD, namely, Mobi-C (metal-on-plastic design) and Prestige LP (metal-on-metal design). The objective of this prospective observational multicenter study was to analyze the first 2-year surgical results of the PMS study of 1-level ACDR in Japan. A total of 54 patients were registered (Mobi-C, n = 24, MC group; Prestige LP, n = 30, PLP group). Preoperative neurological assessment revealed radiculopathy in 31 patients (57.4%) and myelopathy in 15 patients (27.8%). Preoperative radiological assessment classified the disease category as disc herniation in 15 patients (27.8%), osteophyte in 6 patients (11.1%), and both in 33 patients (61.1%). The postoperative follow-up rates at 6 weeks, 6 months, 1 year, and 2 years after ACDR were 92.6%, 87.0%, 83.3%, and 79.6%, respectively. In both groups, patients' neurological condition improved significantly after surgery. Radiographic assessment revealed loss of mobility at the surgical level in 9.5% of patients in the MC group and in 9.1% of patients in the PLP group. No secondary surgeries at the initial surgical level and no serious adverse events were observed in either group. The present results suggest that 1-level ACDR is safe, although medium- to long-term follow-up is mandatory to further verify the validity of ACDR for Japanese patients.

Sacral plexus disorder caused by a wooden toothpick in the rectum.

A 67-year-old man presented with a 2-month history of pain in his right buttock and lower limb. MRI depicted right L5/S1 lateral recess stenosis requiring surgical treatment; however, preoperative CT showed an approximately 7 cm long, thin, rod-shaped structure in the rectum, which was ultimately determined to be an accidentally ingested toothpick. It was removed surgically 6 days after diagnosis, because right leg pain worsened rapidly. The pain disappeared thereafter, and the symptoms have not recurred since. The pain might have been localised to the right buttock and posterior thigh in the early stages because the fine tip of the toothpick was positioned to the right of the anterior ramus of the S2 spinal nerve. Although sacral plexus disorder caused by a rectal foreign body is extremely rare, physicians should be mindful to avoid misdiagnosis.

Case Report: Spinal Stabilization Surgery Using a Novel Custom-Made Titanium Fixation System for the Spinal Instability Caused by Vertebral Malformation in a Dog.

A 2-year-old Maltese was presented with wobbly gait of the pelvic limbs. Based on imaging examinations, a diagnosis of congenital malformation at T5-T8 and severe kyphosis causing spinal cord compression at T6-T7 was made. Dorsal laminectomy and stabilization of T6 and T7 vertebrae were performed. As the size of the vertebrae was small and they were severely deformed, novel custom-made titanium implants were used for spinal stabilization. Clinical signs were resolved 2 weeks after surgery. Although radiographic examination 373 days after surgery showed slight loosening of implants, post-operative course remained uneventful. This report describes the use of novel custom-made titanium implants for spinal fixation surgery in a dog.

Long term outcome and adjacent disc degeneration after anterior cervical discectomy and fusion with titanium cylindrical cages.

BACKGROUND: Anterior cervical discectomy and fusion (ACDF) is widely performed for the treatment of cervical spinal degenerative disease. Autogenic or allogenic bone grafts are used for interbody fusion with satisfactory long term outcomes. However, harvest of the autograft causes donor site complications and allograft is associated with low fusion rate. Threaded titanium cages (TC) have recently been introduced to cope with these disadvantages, but there is little evidence of long term results. METHODS: The long term outcome was studied after ACDF using TC. Clinical and imaging follow up was performed in 41 patients for at least 5 years (range 5-8.3 years). New computer-assisted measurement methods for radiographs are proposed. FINDINGS: ACDF with TC achieved 80% excellent or good outcome by Odom's criteria, 95% fusion rate, and few minor complications. Asymptomatic adjacent disc degeneration was detected in 50% of the patients by our measurement methods. However, symptomatic adjacent disc degeneration occurred in 5% of the patients and only 2% required additional surgery. CONCLUSIONS: These results are comparable or better than those after ACDF with autograft or allograft. ACDF with TC can achieve rigid fixation and provide good long term results.

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.

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.

Clinical application of 3D printing technology to the surgical treatment of atlantoaxial subluxation in small breed dogs.

Atlantoaxial instability (AAI)/subluxation commonly occurs in small breed dogs. Ventral stabilization techniques using screws and/or pins and a plate or, more commonly, polymethylmethacrylate are considered to provide the most favorable outcome. However, the implantation of screws of sufficient sizes for long-term stability becomes challenging in toy breed dogs (e.g. <2 kg). We herein report the application of 3D printing technology to implant trajectory planning and implant designing for the surgical management of AAI in 18 dogs. The use of our patient-specific drill guide templates resulted in overall mean screw corridor deviations of less than 1 mm in the atlas and axis, which contributed to avoiding iatrogenic injury to the surrounding structures. The patient-specific titanium plate was effective for stabilizing the AA joint and provided clinical benefits to 83.3% of cases (15/18). Implant failure requiring revision surgery occurred in only one case, and the cause appeared to be related to the suboptimal screw-plate interface. Although further modifications are needed, our study demonstrated the potential of 3D printing technology to be effectively applied to spinal stabilization surgeries for small breed dogs, allowing for the accurate placement of screws and minimizing peri- and postoperative complications, particularly at anatomical locations at which screw corridors are narrow and technically demanding.

Model mice for mild-form glycine encephalopathy: behavioral and biochemical characterizations and efficacy of antagonists for the glycine binding site of N-methyl D-aspartate receptor.

Glycine encephalopathy (GE) is caused by an inherited deficiency of the glycine cleavage system (GCS) and characterized by accumulation of glycine in body fluids and various neurologic symptoms. Coma and convulsions develop in neonates in typical GE while psychomotor retardation and behavioral abnormalities in infancy and childhood are observed in mild GE. Recently, we have established a transgenic mouse line (low-GCS) with reduced GCS activity (29% of wild-type (WT) C57BL/6) and accumulation of glycine in the brain (Stroke, 2007; 38:2157). The purpose of the present study is to characterize behavioral features of the low-GCS mouse as a model of mild GE. Two other transgenic mouse lines were also analyzed: high-GCS mice with elevated GCS activity and low-GCS-2 mice with reduced GCS activity. As compared with controls, low-GCS mice manifested increased seizure susceptibility, aggressiveness and anxiety-like activity, which resembled abnormal behaviors reported in mild GE, whereas high-GCS mice were less sensitive to seizures, hypoactive and less anxious. Antagonists for the glycine-binding site of the N-methyl-D-aspartate receptor significantly ameliorated elevated locomotor activity and seizure susceptibility in the low-GCS mice. Our results suggest the usefulness of low-GCS mice as a mouse model for mild GE and a novel therapeutic strategy.

Negative pressure pulmonary edema following foramen magnum decompression for Chiari malformation type I.

A 57-year-old obese female presented with vagal and hypoglossal nerve pareses, and magnetic resonance imaging revealed Chiari malformation type I. Standard surgical treatment for Chiari malformation type I was successfully performed. However, immediately after the patient was extubated, she developed signs of upper airway obstruction and chest radiography revealed pulmonary edema. Her ventilation was assisted by maintaining positive end-expiratory pressure at 8 cmH2O. Intravenous furosemide and hydrocortisone were administered. Her respiratory status improved 12 hours later, and she was extubated 3 days after the operation. Postextubational course was uneventful, and the patient was discharged 2 weeks after extubation. The initial neurological deficits had mostly disappeared by 10 months after the operation. This unusual case of negative pressure pulmonary edema indicates that obesity and lower cranial nerve paresis are further risk factors for pulmonary edema as a postextubational complication of surgical treatment.

Neurologic Complications in Managing Degenerative Cervical Myelopathy: Pathogenesis, Prevention, and Management.

Degenerative cervical myelopathy is a common neurologic condition induced by compression of the spinal cord due to degenerative changes of the cervical spine. It is one of the leading causes of acquired disability in adults and manifests as a slow deterioration of the symptoms in a majority of the patients. A variety of nonsurgical and surgical treatments have been performed to ameliorate or halt the symptoms, and a number of articles describe their methods, efficacy, and complications. In this article, the pathogenesis, prevention, and management of the neurologic complications are reviewed.

Prospective Multicenter Study of a Multistep Screw Insertion Technique Using Patient-Specific Screw Guide Templates for the Cervical and Thoracic Spine.

STUDY DESIGN: A prospective clinical study of a multistep screw insertion method using a patient-specific screw guide template system (SGTS) for the cervical and thoracic spine. OBJECTIVE: To evaluate the efficacy of SGTS for inserting screws into the cervical and thoracic spine. SUMMARY OF BACKGROUND DATA: Posterior screw fixation is a standard procedure for spinal instrumentation; however, screw insertion carries the risk of injury to neuronal and vascular structures. METHODS: Preoperative bone images of the computed tomography (CT) scans were analyzed using 3D/multiplanar imaging software, and the screw trajectories were planned. Plastic templates with screw-guiding structures were created for each lamina using 3D design and printing technology. Three types of templates were made for precise multistep guidance, and all the templates were specially designed to fit and lock onto the lamina during the procedure. In addition, plastic vertebra models were generated, and preoperative screw insertion simulation was performed. This patient-specific SGTS was used to perform the surgery, and CT scanning was used to postoperatively evaluate screw placement. RESULTS: Enrolled to verify this procedure were 103 patients with cervical, thoracic, or cervicothoracic pathologies. The SGTS were used to place 813 screws. Preoperatively, each template was found to fit exactly and to lock onto the lamina of the vertebra models. In addition, intraoperatively, the templates fit and locked onto the patient lamina, and the screws were inserted successfully. Postoperative CT scans confirmed that 801 screws (98.5%) were accurately placed without cortical violation. There were no injuries to the vessels or nerves. CONCLUSION: The multistep, patient-specific SGTS is useful for intraoperative pedicle screw (PS) navigation in the cervical and thoracic spine. This method improves the accuracy of PS insertion and reduces the operating time and radiation exposure during spinal fixation surgery. LEVEL OF EVIDENCE: 3.