Objective:To evaluate the efficacy of 3D printing technology combined with computer navigation-assisted screw implantation in the treatment of atlantoaxial instability (AAI) complicated by vertebral artery anomalies.Methods:A retrospective case series study was conducted to analyze the clinical data of 23 patients with AAI complicated by vertebral artery anomalies who were admitted to Honghui Hospital of Xi′an Jiaotong University between January 2019 and January 2023, including 10 males and 13 females, aged 19-70 years [(51.0±13.3)years]. Vertebral artery anomalies were categorized into unilateral high-riding vertebral artery with unilateral dominance ( n=14), bilateral high-riding vertebral arteries with unilateral dominance ( n=6), and ponticulus posticus ( n=3). All the patients underwent preoperative planning using a 3D-printed model of the atlantoaxial complex with the vertebral artery, followed by posterior atlantoaxial pedicle screw fixation with computer-assisted navigation. Operative duration and intraoperative blood loss were recorded. The accuracy of pedicle screw placement was assessed at 3 days postoperatively using the Gertzbein-Robbins classification. Visual analogue scale (VAS) scores and Japanese Orthopedic Association (JOA) scores were evaluated preoperatively, at 3 days, 3 months postoperatively, and at the last follow-up. Bony fusion was assessed using cervical CT with 3D reconstruction at the last follow-up. Complications were also observed. Results:All the patients were followed up for 12-19 months [(15.1±1.9)months]. The operative duration was 125-167 minutes [(140.6±10.9)minutes] and intraoperative blood loss was 200-600 ml [(295.7±77.8)ml]. At 3 days postoperatively, all the 66 pedicle screws were safely placed, with 60 screws (91%) rated as Gertzbein-Robbins Grade 0 and 6 screws (9%) as Grade 1. At 3 days and 3 months postoperatively, and at the last follow-up, the VAS scores were (4.0±1.0)points, (2.0±0.6)points, and (1.3±0.5)points, and the JOA scores were (14.2±1.2)points, (16.0±0.8)points, and (16.6±0.5)points, both of which were not only significantly improved compared with preoperative (5.6±1.3)points and (12.8±1.5)points, but also further improved over time ( P<0.05). At the last follow-up, 22 patients (96%) achieved satisfactory atlantoaxial bony fusion. No vertebral artery injury, spinal cord or nerve injury, cerebrospinal fluid leakage, or screw loosening were observed in any patients. Conclusion:For patients with AAI complicated by vertebral artery anomalies, 3D printing combined with computer navigation-assisted navigation for atlantoaxial pedicle screw implantation offers multiple advantages, including minimal surgical trauma, high screw placement accuracy, pain relief, neurological function improvement, high fusion rate, and lowered incidence of complications.

Objective:To evaluate the efficacy of 3D printing technology combined with computer navigation-assisted screw implantation in the treatment of atlantoaxial instability (AAI) complicated by vertebral artery anomalies.Methods:A retrospective case series study was conducted to analyze the clinical data of 23 patients with AAI complicated by vertebral artery anomalies who were admitted to Honghui Hospital of Xi′an Jiaotong University between January 2019 and January 2023, including 10 males and 13 females, aged 19-70 years [(51.0±13.3)years]. Vertebral artery anomalies were categorized into unilateral high-riding vertebral artery with unilateral dominance ( n=14), bilateral high-riding vertebral arteries with unilateral dominance ( n=6), and ponticulus posticus ( n=3). All the patients underwent preoperative planning using a 3D-printed model of the atlantoaxial complex with the vertebral artery, followed by posterior atlantoaxial pedicle screw fixation with computer-assisted navigation. Operative duration and intraoperative blood loss were recorded. The accuracy of pedicle screw placement was assessed at 3 days postoperatively using the Gertzbein-Robbins classification. Visual analogue scale (VAS) scores and Japanese Orthopedic Association (JOA) scores were evaluated preoperatively, at 3 days, 3 months postoperatively, and at the last follow-up. Bony fusion was assessed using cervical CT with 3D reconstruction at the last follow-up. Complications were also observed. Results:All the patients were followed up for 12-19 months [(15.1±1.9)months]. The operative duration was 125-167 minutes [(140.6±10.9)minutes] and intraoperative blood loss was 200-600 ml [(295.7±77.8)ml]. At 3 days postoperatively, all the 66 pedicle screws were safely placed, with 60 screws (91%) rated as Gertzbein-Robbins Grade 0 and 6 screws (9%) as Grade 1. At 3 days and 3 months postoperatively, and at the last follow-up, the VAS scores were (4.0±1.0)points, (2.0±0.6)points, and (1.3±0.5)points, and the JOA scores were (14.2±1.2)points, (16.0±0.8)points, and (16.6±0.5)points, both of which were not only significantly improved compared with preoperative (5.6±1.3)points and (12.8±1.5)points, but also further improved over time ( P<0.05). At the last follow-up, 22 patients (96%) achieved satisfactory atlantoaxial bony fusion. No vertebral artery injury, spinal cord or nerve injury, cerebrospinal fluid leakage, or screw loosening were observed in any patients. Conclusion:For patients with AAI complicated by vertebral artery anomalies, 3D printing combined with computer navigation-assisted navigation for atlantoaxial pedicle screw implantation offers multiple advantages, including minimal surgical trauma, high screw placement accuracy, pain relief, neurological function improvement, high fusion rate, and lowered incidence of complications.

Fetal ventriculomegaly is a central nervous system disorder commonly seen in prenatal imaging,and the prognosis ranges from normal health to severe dysfunction.Currently,fetal predictive markers associated with postpartum individual neurodevelopmental function are still not available,which increases the difficulty of prenatal diagnosis and clinical management.Constant advancements in magnetic resonance imaging(MRI)technology have brought better accuracy and reliability of MRI applied in the diagnosis,prognosis assessment,and etiology investigation of ventriculomegaly.MRI plays a critical role in prognostic management and prenatal consultation.Nevertheless,due to the potential safety hazards and economic and technical constraints of MRI,it is not the first choice for prenatal imaging diagnosis.Moreover,there are different opinions regarding the measurement results and grading criteria of ultrasound and MRI.At present,it is accepted that three-dimensional volume may provide reliable information for prognosis.However,accurate segmentation and measurement of brain structure remain serious challenges,and no consensus on the MRI measurement of lateral ventricle volume has been reached.In this paper,based on the latest research reports from China and around the world,we reviewed the progress in applying MRI in the prenatal diagnosis and treatment of ventriculomegaly.This review offers a theoretical foundation for further exploration of the role of lateral ventricle volume measurement in disease diagnosis and management.We suggest that researchers combine two-dimensional width with three-dimensional volume in the future to identify the optimal cutoff value for prognostic prediction of fetal ventriculomegaly.