BACKGROUND:For thoracolumbar spine fractures with developmental stenosis of the vertebral arch,accurate nail placement is difficult using traditional fluoroscopy-assisted techniques.O-arm navigation assistance systems offer higher precision in general vertebral arch nail placement,but there is scarce literature on the application of O-arm navigation-assisted nail placement in thoracolumbar spine fractures with developmental stenosis of the vertebral arch both domestically and abroad. OBJECTIVE:To explore the accuracy of percutaneous vertebral arch nail placement assisted by O-arm navigation in patients with thoracolumbar spine fractures complicated by developmental stenosis of the vertebral arch. METHODS:A retrospective analysis was conducted on 53 patients who underwent percutaneous vertebral arch screw fixation surgery at Department of Orthopedics,General Hospital of Central Theater Command of PLA for thoracolumbar spine fractures complicated by developmental stenosis of the vertebral arch from January 2021 to March 2023.Totally 208 cases of vertebral arch developmental stenosis were found(cases with multiple vertebral arch developmental stenosis were counted separately).Based on the surgical approach,the patients were divided into two groups:O-arm navigation group(n=98)and C-arm fluoroscopy group(n=110).Postoperative imaging data were compared between the two groups,including anatomical perforation score,functional perforation score,actual vs.expected nail trajectory in the horizontal plane,and sagittal plane angle differences. RESULTS AND CONCLUSION:(1)There was no significant difference in the narrowest width of the pedicle isthmus(pow)between the two groups of patients(P>0.05).The proportions of different degrees of narrowing(mild:6 mm≤pow<7 mm,moderate:5 mm≤pow<6 mm,severe:pow<5 mm)were also not significantly different between the two groups(P>0.05).(2)The overall grade and scores of anatomical perforation and functional perforation were lower in the O-arm group compared to the C-arm group,and these differences were statistically significant(P<0.001).In terms of the angular deviation between the actual and planned screw trajectories,the O-arm group had smaller deviations,and these differences were statistically significant(P<0.05).(3)In the mild and moderate narrowing groups,the O-arm group showed significant advantages in anatomical perforation,functional perforation,and angular deviation between actual and planned screw trajectories,and these differences were statistically significant(P<0.001).(4)The O-arm group demonstrated better performance in anatomical perforation and functional perforation,especially in the T12-L2 segment,with more significant advantages.Additionally,the O-arm group had better angular deviations in actual and planned screw trajectories in all segments compared to the C-arm group.(5)Therefore,the use of O-arm navigation-assisted percutaneous screw placement for the treatment of thoracolumbar fractures with developmental pedicle isthmal narrowing provides higher accuracy and safer surgery.

OBJECTIVE: To explore the anatomical parameters of the cervical uncinate process "inflection point" through cervical CT angiography (CTA) and MRI measurements, offering a reliable and safe anatomical landmark for anterior cervical decompression surgery. METHODS: A retrospective analysis was conducted on the cervical CTA and MRI imaging data of normal adults who met the selection criteria between January 2020 and January 2024. The CTA dataset included 326 cases, with 200 males and 126 females, aged 22-55 years (mean, 46.7 years). The MRI dataset included 300 cases, with 200 males and 100 females, aged 18-55 years (mean, 43.7 years). Based on the CTA data, three-dimensional models of C ₃-C ₇ were constructed, and the following measurements were obtained from the superior view: uncinate process "inflection point" to vertebral artery distance (UIVD), uncinate process tip to vertebral artery distance (UTVD), uncinate process "inflection point" to "inflection point" distance (UID), uncinate process long-axis to sagittal angle (ULSA), and uncinate process "inflection point" to transverse foramen-sagittal angle (UITSA). From the anterior view, the anterior uncinate process to sagittal angle (AUSA) was measured. From the posterior view, the posterior uncinate process to sagittal angle (PUSA) was measured. Based on the MRI data, uncinate process "inflection point" to dural sac distance (UIDD) and dural sac width (DSW) were measured. The trends in measurement parameters of C ₃-C ₇ were observed, and the differences in measurement parameters between genders and between the left and right sides of the same segment were compared, as well as the difference in UID and DSW within the same segment was compared. RESULTS: The measurement parameters from C ₃ to C ₇ in the CTA data showed a general increasing trend, with no significant difference between the left and right sides within the same segment ( P>0.05). The UIVD, UTVD, and UID were greater in males than in females, with significant differences observed in the UIVD and UTVD at C ₃ and C ₆ and UID at C ₃, C ₆, and C ₇ ( P<0.05). The MRI measured DSW showed a general increasing trend from C ₃ to C ₇, and the DSW at C ₆ was greater in females than in males, with a significant difference ( P<0.05). The UIDD showed a gradual decreasing trend, with the smallest value at C ₆. There was no significant difference between males and females or between the left and right sides within the same segment ( P>0.05). The UID was greater than the DSW at C ₃-C ₇, and the differences were significant ( P<0.05). CONCLUSION The uncinate process "inflection point" is a constant anatomical structure located at the anteromedial aspect of the uncinate process tip and laterally to the dural sac. It maintains a certain safe distance from the vertebral artery. As a decompression landmark in anterior cervical spine surgery, it not only ensures surgical safety but also guarantees complete decompression.
Humans ; Adult ; Male ; Female ; Middle Aged ; Retrospective Studies ; Cervical Vertebrae/surgery* ; Magnetic Resonance Imaging ; Decompression, Surgical/methods* ; Young Adult ; Adolescent ; Computed Tomography Angiography ; Imaging, Three-Dimensional ; Vertebral Artery/anatomy & histology* ; Anatomic Landmarks/diagnostic imaging*

The unilateral biportal endoscopic spinal surgery(UBE)technique is an emerging endoscopic technique,mainly used as treatment for lumbar degenerative disease.The procedure is characterized by two working channels,one being endoscopic,the second to be employed as an operating channel.Through the use of such dual-channel-technology,it allows the operating instruments to be unrestricted in size.Therefore,it is a highly efficient surgical technique for minimally invasive spinal surgery(MISS).However,the clinical complications of UBE technology must be taken into consideration.Possible side effects include dural injury,epidural hematoma,occult blood loss,postoperative headache,nerve root injury and insufficient decompression.This article reviews the causes,prevention and management of UBE-related complications.

Objective:To evaluate the posterior fixation with inclined-long pedicle screws for the injured vertebra combined with two-level interbody fusion for thoracolumbar burst fractures with severe disc injury.Methods:A retrospective study was conducted to analyze the clinical data of 22 patients who had been treated for thoracolumbar burst fractures with severe disc injury at Department of Orthopaedic, General Hospital of Central Theater Command from June 2016 to June 2021. There were 15 males and 7 females, aged 43.50 (29.75, 52.25) years. By the AO classification, there were 12 cases of type B2, 10 cases of type C3. All the patients were treated by the posterior fixation with inclined-long pedicle screws for the injured vertebra combined with two-level interbody fusion. The visual analogue scale (VAS), Oswestry disability index (ODI), anterior vertebral height ratio (AVHR), kyphosis Cobb angle (KCA), vertebral wedge angle (VWA) and spinal canal encroachment rate (SCER) were compared between pre-surgery, 1 week post-surgery, 3 months post-surgery and the last follow-up. Their neurological function was graded according to the American Spinal Injury Association (ASIA) impairment scale and interbody fusion evaluated according to their 3D CT at the last follow-up.Results:All the 22 patients were followed up for (26.1±1.3) months. In all patients, the VAS and ODI were significantly lower at 1 week post-surgery than the pre-surgery ones ( P<0.05), and then decreased significantly at 3 months post-surgery and at the last follow-up compared with the values at 1 week post-surgery ( P<0.05). For all patients, there were significant improvements in AVHR, KCA, VWA and SCER at 1 week post-surgery, 3 months post-surgery and the last follow-up compared with the pre-surgery values ( P<0.05), and the SCER at the last follow-up was significantly decreased compared with that at 1 week post-surgery ( P<0.05). All patients experienced improved neurological function in different degrees at the last follow-up, and all intervertebral spaces achieved solid bony fusion. Conclusion:In the treatment of thoracolumbar burst fractures with severe disc injury, the posterior fixation with inclined-long pedicle screws for the injured vertebra combined with two-level interbody fusion can lead to satisfactory long-term therapeutic efficacy, because this strategy can effectively reduce spinal canal encroachment, restore the height of the injured vertebra, reconstruct the curvature of the fracture area and ensure reliable intervertebral fusion.