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Scientific Reports Feb 2024Lumbo-sacral transitional vertebrae (LSTV) are frequent congenital variances of the spine and are associated with increased spinal degeneration. Nevertheless, there is a...
Lumbo-sacral transitional vertebrae (LSTV) are frequent congenital variances of the spine and are associated with increased spinal degeneration. Nevertheless, there is a lack of data whether bony alterations associated with LSTV result in reduced segmental restoration of lordosis when performing ALIF. 58 patients with monosegmental stand-alone ALIF in the spinal segment between the 24th and 25th vertebra (L5/S1)/(L5/L6) where included. Of these, 17 patients had LSTV and were matched to a control population by age and sex. Pelvic incidence, pelvic tilt, sagittal vertical axis, lumbar lordosis, segmental lordosis, disc height and depth were compared. LSTV-patients had a significantly reduced segmental lordosis L4/5 (p = 0.028) and L5/S1/(L5/L6) (p = 0.041) preoperatively. ALIF resulted in a significant increase in segmental lordosis L5/S1 (p < 0.001). Postoperatively, the preoperatively reduced segmental lordosis was no longer significantly different in segments L4/5 (p = 0.349) and L5/S1/(L5/6) (p = 0.576). ALIF is associated with a significant increase in segmental lordosis in the treated segment even in patients with LSTV. Therefore, ALIF is a sufficient intervention for restoring the segmental lordosis in these patients as well.
Topics: Humans; Lordosis; Lumbar Vertebrae; Retrospective Studies; Pelvis; Lumbosacral Region; Spinal Fusion
PubMed: 38302558
DOI: 10.1038/s41598-024-53179-w -
Swiss Journal of Palaeontology 2024is a baenid turtle from the Late Cretaceous Hell Creek Formation of the United States of America known from cranial, shell, and other postcranial material. Baenid...
Updated cranial and mandibular description of the Late Cretaceous (Maastrichtian) baenid turtle based on micro-computed tomography scans and new information on the holotype-shell association.
UNLABELLED
is a baenid turtle from the Late Cretaceous Hell Creek Formation of the United States of America known from cranial, shell, and other postcranial material. Baenid turtles are taxonomically diverse and common fossil elements within Late Cretaceous through Eocene faunas. Detailed anatomical knowledge is critical to understanding the systematics and morphological evolution of the group. This is particularly important as baenids represent an important group of continental vertebrates that survived the mass extinction event associated with the Cretaceous/Paleogene boundary. High-resolution micro-computed tomography scanning of the holotype skull reveals additional anatomical details for the already well-known . This includes the revision of some anatomical statements from the original description, but also detailed knowledge on internal anatomical features of the braincase and the description of a well-preserved axis (cervical vertebra 2). Our new detailed description and previous work on the shell and postcrania make one of the best-described, nearly complete baenid turtles, which are often only known from either isolated shell or cranial material. A revised phylogenetic analysis confirms the position of as a derived baenid (Eubaeninae) more closely related to than to .
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1186/s13358-023-00301-6.
PubMed: 38274637
DOI: 10.1186/s13358-023-00301-6 -
Journal of Craniovertebral Junction &... 2023In neurosurgery, posterior approaches intended at the craniovertebral junction are frequently used. The most popular procedures for treating upper cervical instability...
OBJECTIVE
In neurosurgery, posterior approaches intended at the craniovertebral junction are frequently used. The most popular procedures for treating upper cervical instability are C1 lateral mass, C2 pedicle, and C1-C2 transarticular screw stabilization. Due to their proximity to neural structures and the presence of the high-riding vertebral artery (VA), these techniques are complicated. The risk of VA damage can be decreased by mobilizing the VA. Using cadaveric specimens in this study was aimed to demonstrate C2 pedicle and C1-C2 transarticular screw placement with VA mobilization and a novel C2 inferior corpus screw placement technique.
METHODS
In this study, twelve adult cadaveric specimens and two adult dry cadaveric C2 bones were used with the permission and decision of the University Research Ethics Committee. Colored silicone was injected into the arteries and veins of these twelve cadaveric specimens. Then, muscle dissection was performed stepwise, and the C2 vertebrae of the cadavers were revealed with a surgical microscope. Each specimen and entire stages of the dissections were recorded photographically. After cadaver dissections, screw placement was performed with three different techniques. Finally, radiological imaging was done with fluoroscopy.
RESULTS
After dissection, the lateral mass of the C2 vertebra was observed, and lateral to it, the transverse process and foramen were detected with the help of a hook. Next, the posterior wall of the VA groove was removed using a 1 mm thin plate Kerrison rongeur until the VA loop could partially be observed the VA. This enables us to find the top of the loop of the VA and mobilize it inferiorly using a dissector. Following this step, the C1-2 transarticular, C2 pedicle, and the novel C2 inferior corpus screw placement can be performed safely by directly visualizing the artery.
CONCLUSIONS
Due to the nearby neurologic and vascular structures, placing the C2 pedicle and C1-2 transarticular screw is a challenging procedure, especially in high-riding VA cases. However, it is possible to place the C2 pedicle, C1-2 transarticular, and novel C2 inferior corpus screw after the mobilization of the VA. This study aimed to show all of them together on a cadaver for the first time, to understand the anatomy of the C2 vertebra, and to use screw placement techniques to minimize the risk of complications.
PubMed: 38268685
DOI: 10.4103/jcvjs.jcvjs_73_23 -
Journal of Orthopaedic Surgery and... Jan 2024To assess whether there is a difference between measurements of odontoid incidence (OI) and other cervical sagittal parameters by X-ray radiography and those by supine...
OBJECTIVE
To assess whether there is a difference between measurements of odontoid incidence (OI) and other cervical sagittal parameters by X-ray radiography and those by supine magnetic resonance imaging (MRI).
METHODS
Standing X-ray and supine MRI images of 42 healthy subjects were retrospectively analyzed. Surgimap software was employed to measure cervical sagittal parameters including OI, odontoid tilt (OT), C2 slope (C2S), C0-2 angle, C2-7 angle, T1 slope (T1S) and T1S-cervical lordosis (CL). Paired samples t-test was applied to determine the difference between parameters measured by standing X-ray and those by supine MRI. In addition, the statistical correlation between the parameters were compared. The prediction of CL was performed and validated using the formula CL = 0.36 × OI - 0.67 × OT - 0.69 × T1S.
RESULTS
Significant correlations and differences were found between cervical sagittal parameters determined by X-ray and those by MRI. OI was verified to be a constant anatomic parameter and the formula CL = 0.36 × OI - 0.67 × OT - 0.69 × T1S can be used to predict CL in cervical sagittal parameters.
CONCLUSIONS
OI is verified as a constant anatomic parameter, demonstrating the necessity of a combined assessment of cervical sagittal balance by using standing X-ray and supine MRI. The formula CL = 0.36 × OI - 0.67 × OT - 0.69 × T1S can be applied to predict CL in cervical sagittal parameters.
Topics: Humans; Retrospective Studies; Odontoid Process; Cervical Vertebrae; Radiography; Magnetic Resonance Imaging; Lordosis
PubMed: 38218851
DOI: 10.1186/s13018-024-04542-0 -
Scientific Reports Jan 2024This study aims to investigate the feasibility and efficacy of anterior atlantoaxial motion preservation fixation (AMPF) in treating axis complex fractures involving the...
This study aims to investigate the feasibility and efficacy of anterior atlantoaxial motion preservation fixation (AMPF) in treating axis complex fractures involving the odontoid process fracture and Hangman's fractures with C2/3 instability. A retrospective study was conducted on eight patients who underwent AMPF for axis complex fractures at the General Hospital of Central Theater Command from February 2004 to October 2021. The types of axis injuries, reasons for injuries, surgery time, intraoperative blood loss, spinal cord injury classification (American Spinal Injury Association, ASIA), as well as complications and technical notes, were documented. This study included eight cases of type II Hangman's fracture, five cases of type II and three cases of type III odontoid process fracture. Five patients experienced traffic accidents, while three patients experienced falling injuries. All patients underwent AMPF surgery with an average intraoperative blood loss of 288.75 mL and a duration of 174.5 min. Two patients experienced dysphagia 1 month after surgery. The patients were followed up for an average of 15.63 months. One case improved from C to E in terms of neurological condition, three cases improved from D to E, and four cases remained at E. Bony fusion and Atlantoaxial Motion Preservation were successfully achieved for all eight patients. AMPF is a feasible and effective way for simultaneous odontoid process fracture and Hangman's fractures with C2/3 instability, while preserving atlantoaxial movement.
Topics: Humans; Blood Loss, Surgical; Odontoid Process; Retrospective Studies; Fractures, Bone; Motion
PubMed: 38182723
DOI: 10.1038/s41598-024-51367-2 -
BMC Musculoskeletal Disorders Jan 2024For patients with multilevel degenerative cervical myelopathy, laminectomy and posterior cervical fusions (PCF) with instrumentation are widely accepted techniques for... (Observational Study)
Observational Study
BACKGROUND
For patients with multilevel degenerative cervical myelopathy, laminectomy and posterior cervical fusions (PCF) with instrumentation are widely accepted techniques for symptom relief. However, hardware failure is not rare and results in neck pain or even permanent neurological lesions. There are no in-depth studies of hardware-related complications following laminectomy and PCF with instrumentation.
METHODS
The present study was a retrospective, single centre, observational study. Patients who underwent laminectomy and PCF with instrumentation in a single institution between January 2019 and January 2021 were included. Patients were divided into hardware failure and no hardware failure group according to whether there was a hardware failure. Data, including sex, age, screw density, end vertebra (C7 or T1), cervical sagittal alignment parameters (C2-C7 cervical lordosis, C2-C7 sagittal vertical axis, T1 slope, Cervical lordosis correction), regional Hounsfield units (HU) of the screw trajectory and osteoporosis status, were collected and compared between the two groups.
RESULTS
We analysed the clinical data of 56 patients in total. The mean overall follow-up duration was 20.6 months (range, 12-30 months). Patients were divided into the hardware failure group (n = 14) and no hardware failure group (n = 42). There were no significant differences in the general information (age, sex, follow-up period) of patients between the two groups. The differences in fusion rate, fixation levels, and screw density between the two groups were not statistically significant (p > 0.05). The failure rate of fixation ending at T1 was lower than that at C7 (9% vs. 36.3%) (p = 0.019). The regional HU values of the pedicle screw (PS) and lateral mass screw (LMS) in the failure group were lower than those in the no failure group (PS: 267 ± 45 vs. 368 ± 43, p = 0.001; LMS: 308 ± 53 vs. 412 ± 41, p = 0.001). The sagittal alignment parameters did not show significant differences between the two groups before surgery or at the final follow-up (p > 0.05). The hardware failure rate in patients without osteoporosis was lower than that in patients with osteoporosis (14.3% vs. 57.1%) (p = 0.001).
CONCLUSIONS
Osteoporosis, fixation ending at C7, and low regional HU value of the screw trajectory were the independent risk factors of hardware failure after laminectomy and PCF. Future studies should illuminate if preventive measures targeting these factors can help reduce hardware failure and identified more risk factors, and perform long-term follow-up.
Topics: Humans; Laminectomy; Lordosis; Retrospective Studies; Cervical Vertebrae; Spinal Fusion; Pedicle Screws; Osteoporosis
PubMed: 38166792
DOI: 10.1186/s12891-023-07116-z -
Spine Deformity Mar 2024To define the prevalence, characteristics, and treatment approach for proximal junction failure secondary to odontoid fractures in patients with prior C2-pelvis...
PURPOSE
To define the prevalence, characteristics, and treatment approach for proximal junction failure secondary to odontoid fractures in patients with prior C2-pelvis posterior instrumented fusions (PSF).
METHODS
A single institution's database was queried for multi-level fusions (6+ levels), including a cervical component. Posterior instrumentation from C2-pelvis and minimum 6-month follow-up was inclusion criteria. Patients who sustained dens fractures were identified; each fracture was subdivided based on Anderson & D'Alonzo and Grauer's classifications. Comparisons between the groups were performed using Chi-square and T tests.
RESULTS
80 patients (71.3% female; average age 68.1 ± 8.1 years; 45.0% osteoporosis) were included. Average follow-up was 59.8 ± 42.7 months. Six patients (7.5%) suffered an odontoid fracture post-operatively. Cause of fracture in all patients was a mechanical fall. Average time to fracture was 23 ± 23.1 months. Average follow-up after initiation of fracture management was 5.84 ± 4 years (minimum 1 year). Three patients sustained type IIA fractures one of which had a concomitant unilateral C2 pars fracture. Three patients sustained comminuted type III fractures with concomitant unilateral C2 pars fractures. Initial treatment included operative care in 2 patients, and an attempt at non-operative care in 4. Non-operative care failed in 75% of patients who ultimately required revision with proximal extension. All patients with a concomitant pars fracture had failure of non-operative care. Patients with an intact pars were more stable, but 50% required revision for pain.
CONCLUSIONS
In this 11-year experience at a single institution, the prevalence of odontoid fractures above a C2-pelvis PSF was 7.5%. Fracture morphology varied, but 50% were complex, comminuted C2 body fractures with concomitant pars fractures. While nonoperative management may be suitable for type II fractures with simple patterns, more complex and unstable fractures likely benefit from upfront surgical intervention to prevent fracture displacement and neural compression. As all fractures occurred secondary to a mechanical fall, inpatient and community measures aimed to minimize risk and prevent mechanical falls would be beneficial in this high-risk group.
Topics: Humans; Female; Middle Aged; Aged; Male; Odontoid Process; Spinal Fractures; Fracture Fixation, Internal; Fractures, Bone; Pelvis
PubMed: 38157096
DOI: 10.1007/s43390-023-00800-z -
Journal of Clinical Medicine Dec 2023In a multilevel cervical laminoplasty operation for patients with cervical spondylotic myelopathy (CSM), a partial or complete C3 laminectomy may be performed at the...
INTRODUCTION
In a multilevel cervical laminoplasty operation for patients with cervical spondylotic myelopathy (CSM), a partial or complete C3 laminectomy may be performed at the upper level instead of a C3 plated laminoplasty. It is unknown whether C3 technique above the laminoplasty affects loss of cervical lordosis or range of motion.
METHODS
Patients undergoing multilevel laminoplasty of the cervical spine (C3-C6/C7) at a single institution were retrospectively reviewed. Patients were divided into two cohorts based on surgical technique at C3: C3-C6/C7 plated laminoplasty ("C3 laminoplasty only", N = 61), C3 partial or complete laminectomy, plus C4-C6/C7 plated laminoplasty (N = 39). All patients had at least 1-year postoperative X-ray treatment.
RESULTS
Of 100 total patients, C3 laminoplasty and C3 laminectomy were equivalent in all demographic data, except for age (66.4 vs. 59.4 years, = 0.012). None of the preoperative radiographic parameters differed between the C3 laminoplasty and C3 laminectomy cohorts: cervical lordosis (13.1° vs. 11.1°, = 0.259), T1 slope (32.9° vs. 29.2°, = 0.072), T1 slope-cervical lordosis (19.8° vs. 18.6°, = 0.485), or cervical sagittal vertical axis (3.1 cm vs. 2.7 cm, = 0.193). None of the postoperative radiographic parameters differed between the C3 laminoplasty and C3 laminectomy cohorts: cervical lordosis (9.4° vs. 11.2°, = 0.369), T1 slope-cervical lordosis (21.7° vs. 18.1°, = 0.126), to cervical sagittal vertical axis (3.3 cm vs. 3.6 cm, = 0.479). In the total cohort, 31% had loss of cervical lordosis >5°. Loss of lordosis reached 5-10° (mild change) in 13% of patients and >10° (moderate change) in 18% of patients. C3 laminoplasty and C3 laminectomy cohorts did not differ with respect to no change (<5°: 65.6% vs. 74.3%, respectively), mild change (5-10°: 14.8% vs. 10.3%), and moderate change (>10°: 19.7% vs. 15.4%) in cervical lordosis, = 0.644. When controlling for age, ordinal regression showed that surgical technique at C3 did not increase the odds of postoperative loss of cervical lordosis. C3 laminectomy versus C3 laminoplasty did not differ in the postoperative range of motion on cervical flexion-extension X-rays (23.9° vs. 21.7°, = 0.451, N = 91).
CONCLUSION
There was no difference in postoperative loss of cervical lordosis or postoperative range of motion in patients who underwent either C3-C6/C7 plated laminoplasty or C3 laminectomy plus C4-C6/C7 plated laminoplasty.
PubMed: 38137663
DOI: 10.3390/jcm12247594 -
Journal of Neuroendovascular Therapy 2023Basilar artery occlusion (BAO) secondary to traumatic vertebral artery (VA) dissection caused by vertebral fracture is a rare cause of acute ischemic stroke, and optimal...
OBJECTIVE
Basilar artery occlusion (BAO) secondary to traumatic vertebral artery (VA) dissection caused by vertebral fracture is a rare cause of acute ischemic stroke, and optimal management, such as antithrombotic agents, surgical fixation, and parent artery occlusion (PAO), has been controversial. We report a case in which mechanical thrombectomy and PAO were performed for a BAO due to right VA dissection caused by a transverse foramen fracture of the axis vertebra.
CASE PRESENTATION
A patient in her 80s suffered from a backward fall, and a neck CT revealed a fracture and dislocation of the right lateral mass of the axis and a compressed transverse foramen. The patient was instructed to admit and to remain in bed rest; however, she suddenly lost consciousness the following day. The CTA revealed right VA occlusion and BAO; therefore, the patient underwent mechanical thrombectomy and the BAO was successfully reperfused but the VA stenotic dissection remained. PAO of the right VA was performed on the fifth day after the accident to prevent BAO recurrence.
CONCLUSION
Mechanical thrombectomy is an effective treatment for BAO caused by VA dissection, and PAO may contribute to the prevention of stroke recurrence.
PubMed: 38125961
DOI: 10.5797/jnet.cr.2023-0041 -
Case Reports in Orthopedics 2023The current case series describes three cases of fusion between the 2nd cervical vertebra, the axis (C2), and the 3rd cervical vertebra (C3), creating a C2-C3 osseous...
PURPOSE
The current case series describes three cases of fusion between the 2nd cervical vertebra, the axis (C2), and the 3rd cervical vertebra (C3), creating a C2-C3 osseous complex and highlighting its morphological type of fusion (partial or complete) and morphometric details. The developmental background of this complex is emphasized, pointing out the possible clinical significance.
MATERIALS AND METHODS
The osseous complexes were derived from disarticulated skeletons of body donors and were collected from the osseous collection of the Anatomy Department of the Medical School of the National and Kapodistrian University of Athens.
RESULTS
Three blocked vertebral complexes (2 partial and 1 complete C2-C3 osseous masses) were identified. In two cases, the vertebral bodies were partially fused and in one case were completely fused. In the 1st case, the C2-C3 complex had fused spinous processes and distinct transverse processes. Facets were completely fused on the left and partially fused on the right side. In the 2nd case, the C2-C3 complex had partially fused vertebral bodies and distinguishable spinous processes. In the 3rd case, the C2-C3 complex had completely fused vertebral bodies, facets, laminae, and transverse and spinous processes.
CONCLUSIONS
Among the three (C2-C3) fused osseous complexes, the two were partially and the one was completely ossified. The fused vertebrae were characterized by osteophytic formations (at the dens and C3 area) and osteoporotic lesions. Taking into consideration the C2-C3 fusion, and possible coexisted variants, particular caution should be made in the upper cervical area, to interpret possible neurological manifestations and to reach a safe surgical plan.
PubMed: 38076299
DOI: 10.1155/2023/3577693