Lateral Mass Research Articles

Selecting the lowest instrumented vertebra in a multilevel posterior cervical fusion across the cervicothoracic junction: a biomechanical investigation.

Posterior cervical fusion is a common surgical treatment for patients with myeloradiculopathy or regional deformity. Several studies have found increased stresses at the cervicothoracic junction (CTJ) and significantly higher revision surgery rates in multilevel cervical constructs that terminate at C7. The purpose of this study was to investigate the biomechanical effects of selecting C7 versus T1 versus T2 as the lowest instrumented vertebra (LIV) in multisegmental posterior cervicothoracic fusion procedures. Seven fresh-frozen cadaveric cervicothoracic spines (C2-L1) with ribs intact were tested. After analysis of the intact specimens, posterior rods and lateral mass screws were sequentially added to create the following constructs: C3-7 fixation, C3-T1 fixation, and C3-T2 fixation. In vitro flexibility tests were performed to determine the range of motion (ROM) of each group in flexion-extension (FE), lateral bending (LB), and axial rotation (AR), and to measure intradiscal pressure of the distal adjacent level (DAL). In FE, selecting C7 as the LIV instead of crossing the CTJ resulted in the greatest increase in ROM (2.54°) and pressure (29.57 pound-force per square inch [psi]) at the DAL in the construct relative to the intact specimen. In LB, selecting T1 as the LIV resulted in the greatest increase in motion (0.78°) and the lowest increase in pressure (3.51 psi) at the DAL relative to intact spines. In AR, selecting T2 as the LIV resulted in the greatest increase in motion (0.20°) at the DAL, while selecting T1 as the LIV resulted in the greatest increase in pressure (8.28 psi) in constructs relative to intact specimens. Although these trends did not reach statistical significance, the observed differences were most apparent in FE, where crossing the CTJ resulted in less motion and lower intradiscal pressures at the DAL. The present biomechanical cadaveric study demonstrated that a cervical posterior fixation construct with its LIV crossing the CTJ produces less stress in its distal adjacent discs compared with constructs with C7 as the LIV. Future clinical testing is necessary to determine the impact of this finding on patient outcomes.

Minimally invasive modification of the Goel-Harms atlantoaxial fusion technique: a case series and illustrative guide.

The Goel-Harms atlantoaxial screw fixation technique for the treatment of atlantoaxial instability and unstable odontoid fractures is reliable and reproducible for a variety of anatomies. The drawbacks of the technique are the potential for significant bleeding from the C2 nerve root venous plexus and the risks associated with posterior midline exposure and retraction, such as pain and wound complications. The authors developed a minimally invasive surgical (MIS) modification of the Goel-Harms technique using intra-articular grafting to facilitate placement of percutaneous lateral mass and pars screws with extended tabs for minimally invasive subfascial rod placement. The objective of this study was to present the authors' first series of 5 patients undergoing minimally invasive modification in comparison with 51 patients undergoing open atlantoaxial fusion. A retrospectiveanalysis of patient comorbid conditions, blood loss, length of surgery, and length of stay was performed on patients undergoing Goel-Harms instrumented fusion (GHIF) for unstable odontoid fractures performed between 2016 and 2021. Patients undergoing the minimally invasive procedure showed significantly less blood loss than those undergoing the open atlantoaxial fusion procedure, with a median blood loss of 30 ml compared with 150 ml using the open technique (p < 0.01). The patients showed no significant differences in length of stay (2 days for MIS vs 4 days for open atlantoaxial fusion, p = 0.25). There were no significant differences in length of surgery for MIS, but a possible trend toward increased operative duration (234 vs 151 minutes, p = 0.112). In this small pilot study, it was shown that MIS-GHIF can be performed with decreased blood loss in atlantoaxial instability and odontoid fractures. This technique may allow for greater and safer application of the procedure in the elderly and infirm.

Complications associated with subaxial placement of pedicle screws versus lateral mass screws in the cervical spine (C2-T1): systematic review and meta-analysis comprising 4,165 patients and 16,669 screws.

Lateral mass screw (LMS) and cervical pedicle screw (CPS) fixation are among the most popular techniques for posterior fusion of the cervical spine. Early research prioritized the LMS approach as the trajectory resulted in fewer neurovascular complications; however, with the incorporation of navigation assistance, the CPS approach should be re-evaluated. Our objective was to report the findings of a meta-analysis focused on comparing the LMS and CPS techniques in terms of rate of various complications with inclusion of all levels from C2 to T1. We conducted a systematic review of PubMed and EMBASE databases with final inclusion criteria focused on identifying studies that reported outcomes and complications for either the CPS or LMS technique. These studies were then pooled, and statistical analyses were performed from the cumulative data. A total of 60 studies comprising 4165 participants and 16,669 screws placed within the C2-T1 levels were identified. Within these studies, the LMS group had a significantly increased odds for lateral mass fractures (odds ratio [OR] = 43.2, 95% confidence interval [CI] = 2.62-711.42), additional cervical surgeries (OR = 5.56, 95%CI = 2.95-10.48), and surgical site infections (SSI) (OR = 5.47, 95%CI = 1.65-18.16). No other significant differences between groups in terms of complications were identified. Within the subgroup analysis of navigation versus non-navigation-guided CPS placement, no significant differences were identified for individual complications, although collectively significantly fewer complications occurred with navigation (OR = 5.29, 95%CI = 2.03-13.78). The CPS group had significantly fewer lateral mass fractures, cervical revision surgeries, and SSIs. Furthermore, navigation-assisted CPS placement was associated with a significant reduction in complications overall.

An unusual case of lateral neck swelling: schwannoma revisited

Lateral neck masses can pose a diagnostic challenge with clinicians across the globe. An algorithmic approach with definite investigations usually leads to diagnosing common etiopathogenesis. However, in rare instances it can pose a major challenge and an excision biopsy is both the investigation as well and the therapeutic option. Neurilemmomas are a group of benign nerve sheath tumours and have a pre ponderance for occurrence in head and neck areas. This case report was one such account of unusual neck mass and along with its review of literature.

Non-Surgical Management of Upper Cervical Instability via Improved Cervical Lordosis: A Case Series of Adult Patients

Injury to the head and neck resulting from whiplash trauma can result in upper cervical instability (UCIS), in which excessive movement at C1 on C2 is observed radiologically. In some cases of UCIS there is also a loss of normal cervical lordosis. We postulate that improvement or restoration of the normal mid to lower cervical lordosis in patients with UCIS can improve the biomechanical function of the upper cervical spine, and thus potentially improve symptoms and radiographic findings associated with UCIS. Nine patients with both radiographically confirmed UCIS and loss of cervical lordosis underwent a chiropractic treatment regimen directed primarily at the restoration of the normal cervical lordotic curve. In all nine cases, significant improvements in radiographic indicators of both cervical lordosis and UCIS were observed, along with symptomatic and functional improvement. Statistical analysis of the radiographic data revealed a significant correlation (R2 = 0.46, p = 0.04) between improved cervical lordosis and reduction in measurable instability, determined by C1 lateral mass overhang on C2 with lateral flexion. These observations suggest that enhancing cervical lordosis can contribute to improvement in signs and symptoms of upper cervical instability secondary to traumatic injury.

Evaluation of guaiacyl lignin aromatic structures using 13CO2 administered Ginkgo biloba L. xylem by quantitative solid- and liquid-state 13C NMR

Abstract Ginkgo biloba L. saplings were cultivated in an airtight growth chamber with 13CO2 for two months. The 13C ratio of the newly developed xylem region was ca. 85%, evaluated by high lateral resolution secondary ion mass spectrometry and thioacidolysis/GC-MS. Quantitative solid-state 13C direct polarisation/magic angle spinning (DP/MAS) NMR measurements with high-speed MAS of 70.0 kHz were conducted for cutting-milled wood (CMW), ball-milled wood (BMW), and enzymatically saccharified lignin (EL) samples. In addition, quantitative liquid-state 13C NMR measurements were carried out for EL in DMSO-d 6. Major lignin aromatic signals were classified into three groups of aromatic carbons of C–H, C–C, and C–O, and their area ratio was compared within these measurements. EL samples in solid- and liquid-state showed nearly the same results. However, the results for CMW and BMW in solid-state NMR suggest the structural alteration of lignin within the sample preparation procedure, including ball milling.

Complete Second Branchial Fistula: A Rare Entity.

Second branchial anomalies like branchial cyst, sinus or fistula are common lateral neck masses in pediatric age group but it is rare to encounter complete branchial fistula with external as well as internal openings. We present a case of 16 yrs old female patient with complete Branchial fistula which was diagnosed with the help of CT fistulogram and thereafter taken up for surgical excision of fistula under general anaesthesia. Histopathology confirmed the diagnosis of branchial fistula. In case of lateral neck mass with external opening in pediatric age group strong possibility of diagnosis of branchial fistula should be kept, timely management of the case improves the quality of life.

Lateral Mass Screws Versus Pedicle Screws at C7: Reoperation Rates for Operative Adjacent Segment Disease and Nonunion in Posterior Cervical Fusion.

A retrospective cohort study. To determine if there is a difference in reoperation rates for symptomatic adjacent segment disease (operative ASD) and symptomatic nonunions (operative nonunions) in posterior cervical fusions (PCFs) stopping at C7 using either lateral mass screws (LMS) or cervical pedicle screws (CPS) at C7. Stopping PCFs at C7 has been controversial because of the risks of adjacent segment disease or nonunions. The two commonly used fixation techniques at the C7 level are LMS and CPS. A retrospective analysis from the Kaiser Permanente Spine Registry identified a cohort of patients with cervical degenerative disk disease who underwent primary PCFs stopping at C7 with either LMS or CPS at C7. Demographic and operative data were extracted from the registry, and operative ASD and operative nonunions were adjudicated through chart review. Patients were followed until validated operative ASD or nonunion, membership termination, death, or end of study (March 31, 2022). Descriptive statistics and multivariable Cox proportional hazards models were calculated for operative ASDs and operative nonunions. We found 481 patients with PCFs stopping at C7 with either LMS (n=347) or CPS (n=134) at C7 with an average follow-up time of 5.6 (±3.8) years, time to operative ASD of 3.0 (±2.8) years, and to operative nonunion of 1.2 (±0.7) years. There were 11 operative ASDs (LMS=8, CPS=3) and eight operative nonunions (LMS=4, CPS=4). There was no statistical difference between patients stopping at C7 with LMS versus CPS for operative ASDs (HR: 0.68, 95% CI=0.17-2.77, P =0.60) or operative nonunions (HR: 2.09, 95% CI=0.45-8.58, P =0.37). A large cohort of patients with PCFs stopping at C7 with an average follow-up of > 5 years found no statistical difference in reoperation rates for symptomatic ASD (operative ASD) or operative nonunion using either LMS or CPS at C7.

Posterior osteosynthesis with a new self-designed lateral mass screw-plate system for unstable atlas burst fractures

BackgroundIn the treatment of unstable atlas fractures using the combined anterior–posterior approach or the posterior monoaxial screw-rod system, factors such as severe trauma or complex surgical procedures still need to be improved despite the favourable reduction effect. This research described and evaluated a new technique for the treatment of unstable atlas fracture using a self-designed lateral mass screw-plate system.MethodsA total of 10 patients with unstable atlas fractures using this new screw-plate system from January 2019 to December 2021 were retrospectively reviewed. All patients underwent posterior open reduction and internal fixation (ORIF) with a self-designed screw-plate system. The medical records and radiographs before and after surgery were noted. Preoperative and postoperative CT scans were used to determine the type of fracture and evaluate the reduction of fracture.ResultsAll 10 patients were successfully operated with this new system, with an average follow-up of 16.7 ± 9.6 months. A total of 10 plates were placed, and all 20 screws were inserted into the atlas lateral masses. The mean operating time was 108.7 ± 20.1 min and the average estimated blood loss was 98.0 ± 41.3 ml. The lateral mass displacement (LMD) averaged 7.1 ± 1.9 mm before surgery and almost achieved satisfactory reduction after surgery. All the fractures achieved bony healing without reduction loss or implant failure. No complications (vertebral artery injury, neurologic deficit, or wound infection) occurred in these 10 patients. At the final follow-up, the anterior atlantodens interval (AADI) was 2.3 ± 0.8 mm and the visual analog scale (VAS) was 0.6 ± 0.7 on average. All patients preserved almost full range of motion of the upper cervical spine and achieved a good clinical outcome at the last follow-up.ConclusionsPosterior osteosynthesis with this new screw-plate system can provide a new therapeutic strategy for unstable atlas fractures with simple and almost satisfactory reduction.

Assessment of Cervical Skeletal Trauma: The Synergistic Contribution of Forensic and Clinical Medicine to a Case of Corpse Concealment

Fatal neck injuries represent a major challenge in forensic pathology because the anatomical complexity and high variability of neck structures make it often extremely difficult to differentiate true pathological findings from artifacts at autopsy. This topic becomes even more relevant when the forensic pathologist is required to make a pathophysiological evaluation of bone fractures in the absence of soft tissue to support the diagnosis. We report a case of unidentified, stone-covered, skeletonized human remains found within a pit below an abandoned building with bony lesions of the cervical spine and ribs, including a full-thickness fracture of the right lateral mass of the atlas (C1). After a careful study of the fractures was carried out by screening forensic literature and anthropological studies, clinical neurosurgical expertise was called upon to provide a reliable explanation. A rapid and violent twisting of the neck in the opposite direction from the fracture site by an attacker who pinned the victim's torso is the scenario that most likely occurred in our case. This case report shows that the diagnosis of cervical spine injuries in skeletal remains should be the result of a multidisciplinary approach that integrates forensic, anthropological, and clinical expertise.

The Impact of Rigid Cervical Collars on Outcome of Patients Who Underwent Posterior Cervical Laminectomy and Fusion: A Retrospective Comparative Study.

Retrospective cohort study. This study aimed to investigate the cervical collar impact on the functional outcomes of patients after posterior cervical laminectomy and lateral mass screw fixation (PCLF) surgery. The safety and possible benefits of implementing rigid cervical collars subsequent to PCLF are insufficiently investigated. Patients who underwent PCLF and received postoperative cervical collars from 2018 to 2020 were included in this retrospective cohort study. Their data were compared with an age- and sex-matched group of subjects who did not receive collars after PCLF during the same period. Pain intensity (using the Visual Analog Scale), Neck Disability Index, and quality of life (using 36-item Short Form Health Survey) of the patients were compared at baseline, 1, 3, 6, and 12 months postoperatively. A total of 36 patients who received cervical collars after surgery and 40 controls were included. At baseline and 1-month follow-up, there were no differences in pain intensity, functional status, and quality of life between the groups. However, at 3 months postoperatively, the quality of life of the subjects with no orthosis was higher than those who received cervical collars (p =0.01). At 6- and 12-month follow-up, there were no differences between the groups in pain intensity, functional status, and quality of life. No difference in the pain intensity and functional status of patients who used cervical collars and controls was shown in our study. Patients who did not wear cervical collars had a higher quality of life during the 3-month postoperative evaluation. Future prospective, well-controlled studies with longer follow-ups are needed to further investigate the effects of cervical orthosis on the clinical outcome of patients after PCLF.

Preliminary experience with a novel facet-based lateral mass drill guide for the placement of lateral mass screws compared to freehand technique: a cadaveric study

BACKGROUND CONTEXTLateral mass screw fixation is the standard for posterior subaxial cervical fixation. Several freehand surgical techniques for placing lateral mass screws have been described which rely on anatomical landmarks and surgeon mastery of the technique to safely place screws. The accuracy of these freehand techniques is inherently variable and can be influenced by a surgeon's level of clinical experience. A novel technique was developed that utilizes the plane of the facet joint to create lateral mass screw pilot holes parallel with the joint line to improve the safety and accuracy of lateral mass screw placement regardless of experience. PURPOSETo assess the safety and accuracy of lateral mass screw placement using a novel lateral mass drill guide instrument (LM Guide), compared to standard freehand technique. STUDY DESIGNRandomized cadaveric study utilizing multiple surgeon evaluators to compare the safety and accuracy of guided cervical lateral mass placement compared to traditional freehand techniques. MATERIALS AND METHODSLateral mass screws were placed from C3 to C7 in 20 cadaver specimens by 8 spine surgeons of varying levels of clinical experience (4 attendings, 4 fellows). Screws were placed bilaterally using standard anatomic landmarks (“freehand”) randomly allocated on one side and using the LM Guide on the other. Cadaveric specimens were imaged with high-resolution CT to assess screw placement. Zone grading for safety was conducted based on screw tip position and clinical severity of screw breach was based on proximity to surrounding neurovascular anatomy. Screws were graded as safe, at-risk, or critical, with at-risk and critical screws considered malpositioned. To assess the accuracy of screw trajectory placed using the LM Guide compared to freehand, sagittal screw angle was measured and compared to an “ideal” screw path parallel to the facet joint line. Freehand and LM Guide groups were compared using Pearson's chi-square correlation. RESULTSScrew placement using the LM guide yielded a significantly lower rate of screw malpositioning, with 7 of 91 (7.7%) compared with 18 of 99 (18.2%) screws placed in the At-Risk or Critical Zones, p<.05. Of the 91 screws inserted using the LM Guide, 84 (92.3%) were in the Safe Zone, 7 (7.7%) were At-Risk, and 0 were in Critical zones. There was no incidence of neural or transverse foramen breaches with the LM Guide. In comparison, for the 99 screws inserted freehand, 81 (81.8%) were Safe, 14 (14.1%) were At-Risk, and 4 (4.1%) were in Critical zones. The 4 Critical zone freehand screw breaches included 1 neural foramen breach, 2 transverse foramen breaches, and 1 facet breach. The LM Guide also resulted in higher accuracy of screw trajectory, as indicated by a significant reduction in sagittal screw angle compared with freehand, p<.01. Notably, in the less-experienced surgeon cohort, the LM Guide significantly reduced the sagittal screw angle and resulted in no critical screw breaches compared to 3 critical breaches with freehand technique suggesting there might be a benefit in decreasing the learning curve associated with lateral mass screw placement. CONCLUSIONSLateral mass screw placement with a novel LM Guide that uses the facet joint to control screw trajectory improved the accuracy and reproducibility of screw placement with a significant reduction in screw breach rate and sagittal screw angle compared to freehand techniques regardless of surgeon experience level. CLINICAL SIGNIFICANCEThe inherent variability of freehand lateral mass screw placement can increase the risk of clinical complications associated with screw malpositioning. The technique presented in this cadaveric study may be a viable alternative to standard freehand technique that can improve the overall safety of lateral mass screw placement.

Evaluation of enlarged laminectomy with lateral mass screw fixation in relieving nerve root symptoms and correcting kyphosis for cervical myelopathy and radiculopathy.

This study aimed to compare the surgical efficacy of enlarged laminectomy with lateral mass screw fixation (EL-LMSF) and anterior cervical decompression and fusion (ACDF) for multilevel cervical myelopathy and radiculopathy (CMR) related to kyphosis. 75 patients were retrospectively reviewed and divided into ACDF and EL-LMSF group. Clinical results including operative time, blood loss, and postoperative complications were compared. The JOA scoring system was used to evaluate spinal cord function and the VAS score evaluate nerve root pain severity. Cervical alignment a C2-C7 was measured with Cobb method and compared to confirm the reconstruction effect. Data on 75 patients (M/F: 41:34; EL-LMSF/ACDF:42/33) with the mean age of 57.5 years (range 43-72 year old) were reviewed retrospectively. Discectomy and/or sub-toal corpectomy in ACDF group was performed with a mean of 3.24 levels (range, 3-4). Enlarged laminectomy in EL-LMSF group was performed with a mean of 3.89 enlarged levels (range, 3-5). The procedure of ACDF group showed a shorter operation time (103 ± 22 min vs. 125 ± 37 min, P = 0.000) and less blood loss (78 ± 15 ml vs. 226 ± 31 ml, P = 0.000) compared than that of the EL-LMSF group. Patients treated with EL-LMSF indicated lower VAS for upper extremity (1.3 ± 1.7 vs. 3.3 ± 1.3, P = 0.003) and better curvature corrected (10.7 ± 4.2° vs. 8.5 ± 3.5°, P = 0.013). The difference were of statistical significance. No statistical difference was found after surgery in the JOA score (14.1 ± 1.7 vs. 13.5 ± 2.1, P = 0.222). During the follow-up period, 15.2% of patients in the ACDF group had complications including 2 cases with transient dysphagia, 1 case with C5 palsy, 1 case with axial pain, and 1 case with screw pullout 3 month after surgery. However, only 9.5% of cases in the EL-LMSF group experienced complications, including 3 cases of axial pain and 1 case of epidural hematoma. The EL-LMSF procedure requires a longer operation time and more blood loss because of the incision of the stenosed foramen. However, the procedure has obvious advantages in relieving nerve root symptoms and correcting cervical curvature with fewer postoperative complications.

MORPHOMETRIC ANALYSIS OF ATLAS AND IT'S CLINICAL SIGNIFICANCE: AN ANATOMICAL STUDY OF INDIAN HUMAN ATLAS VERTEBRA.

The atlas and axis are unique in their morphology and also have a complex vertebral artery relationship.The atlas consists of a neurovascular groove for the vertebral artery located behind each lateral mass at the posterior arch of the atlas. Superiorly the vertebral groove is arched by the posterior atlanto-occipitalmembrane, leaving an opening for the upwards passage of the vertebral artery and the outwards passage of the rst cervical spinal nerve. This prospective observational study was conducted in the Department of Anatomy, Government Medical College, Jammu, a total of 40 dry adult atlas vertebrae were measured with the aim to study the morphology of Indian human atlas vertebra and it's clinical signicance. The mean±SD and range of various parameters of atlas were recorded. It was observed that there was no signicant difference between right and left sides which shows bilateral symmetry. The study concluded that various parameters of atlas are helpful for the different neurosurgeries mainly in the surgical procedures of traumatic neck condition to prevent further injuries to vertebral artery and spinal cord

The role of cervical pedicle screw in cervical spine trauma: A single-center retrospective study.

Placement of pedicle screw in the subaxial cervical spine is a challenging and complex technique but provides significant biomechanical advantages. Despite its potential complications, the role and use of cervical pedicle screw (CPS) are growing. A literature review of the significant articles on applying pedicle screws in the subaxial cervical spine was done (articles between 1994 and 2020). Furthermore, our center´s experience of 15 years related to CPS is also discussed in this study. Transpedicular instrumentation in the subaxial cervical spine requires profound anatomical knowledge and meticulous surgical technique. This technique provides superior biomechanical stability compared to the other cervical fixation techniques. Pull-out strength of CPS is twice as compared to the lateral mass screws. There have been numerous variations in the technique of CPS, varying from open techniques to minimally invasive and the use of biomodels and templates during this procedure. Clinically, CPS can be used in different cervical trauma situations, such as fracture-dislocations, floating lateral mass, and fractures associated with ankylosing spondylitis. Despite the possibility of neurovascular injury due to the proximity of the vertebral artery, spinal cord, and spinal nerves to the cervical pedicles, scientific literature, and our center × s experience show low risk, and this technique can be performed safely. CPS placement is a safe procedure, and it has great potential in the management of cervical spine trauma.

RADIOLOGICAL CLASSIFICATION OF THE PELVIS: A TOOL FOR TRAUMA SURGICAL PLANNING

Dysmorphic pelves are a known risk factor for malpositioned iliosacral screws. Improved understanding of pelvic morphology will minimise the risk of screw misplacement, neurovascular injuries and failed fixation. Existing classifications for sacral anatomy are complex and impractical for clinical use. We propose a CT-based classification using variations in pelvic anatomy to predict the availability of transosseous corridors across the sacrum. The classification aims to refine surgical planning which may reduce the risk of surgical complications.The authors postulated 4 types of pelves. The “superior most point of the sacroiliac joint” (sSIJ) typically corresponds with the mid-lower half of the L5 vertebral body. Hence, “the anterior cortex of L5” (L5a) was divided to reference 3 distinct pelvic groups. A 4th group is required to represent pelves with a lumbosacral transitional vertebra. The proposed classification:A – sSIJ is above the midpoint of L5aB – sSIJ is between the midpoint and the lowest point of L5aC – sSIJ is below the lowest point of L5aD – pelves with a lumbosacral transitional vertebraSpecific measures such as the width of the S1 and S2 axial and coronal corridors and the S1 lateral mass angles were used to differentiate between pelvic types.Three-hundred pelvic CT scans were classified into their respective types. Analysis of the specific measures mentioned above illustrated the significant difference between each pelvic type. Changes in the size of S1 and S2 axial corridors formed a pattern that was unique for each pelvic type. The intra- and inter-observer ratings were 0.97 and 0.95 respectively.Distinct relationships between the sizes of S1 and S2 axial corridors informed our recommendations on trans-sacral or iliosacral fixation, number and orientation of screws for each pelvic type. This classification utilises variations in the posterior pelvic ring to offer a planning guide for the insertion of iliosacral screws.

Accuracy of atlantoaxial screw placement using computed tomography-based navigation system-assisted surgery: The single-level vertebral registration

ObjectivePosterior screw fixation via a C1 lateral mass screw combined with a C2 pedicle screw is a well-known technique for atlantoaxial instability. However, screw malposition can occur because of the complex anatomical structure of this region. This study aimed to evaluate the accuracy and risk factors of cortical breach following the C1 lateral mass and/or C2 pedicle screw insertion using a preoperative computed tomography (CT)-based navigation system with a single-level vertebral registration method. MethodsThis retrospective cohort study included patients who had undergone a C1 lateral mass and/or a C2 pedicle screw placement using a preoperative CT-based navigation system from January 2013 to March 2020 from the university hospital. The extent of screw deviation was classified as: within the pedicle (grade 0), out of pedicle < 2 mm (grade I), from 2 to 4 mm (grade II), and > 4 mm (grade III). The risk of cortical breach was evaluated using multivariate analysis. ResultsSeventy-eight C1 lateral masses and 71 C2 pedicle screws were inserted into 42 patients. The accuracy of screw placement was as follows: 133 grade 0 (89.3 %), 14 grade I (9.4 %), and two grade II (1.3 %). No screws required repositioning, and no vertebral artery injury or neurological deficit was associated with this technique. Additionally, a diameter of < 5 mm was associated with the cortical breach in the multivariate analysis. ConclusionsC1 lateral mass and C2 pedicle screw placement could be safely and effectively performed by using a preoperative CT-based navigation system with a single-level registration technique. The risk factors for cortical breach are the C1 lateral mass and C2 pedicle diameters.

Sudden Appearance of a Palpable Chest Wall Mass Secondary to Macrocystic Lymphatic Malformation: A Case Report

Chest wall lymphatic malformations are rare and can pose a diagnostic dilemma, particularly if they present abruptly. This case report describes a 15-month-old male toddler presenting with a left lateral chest mass. Histopathology of the surgically excised mass confirmed the diagnosis of a macrocystic lymphatic malformation. Furthermore, there was no recurrence of the lesion in the two-year follow-up period.

Paracondylar process and epitransverse process on cone beam computed tomography: a pictorial review based on a serie of 9 patients

Objective: Paracondylar (PCP) and epitransverse processes (ETP) represent rare types of articulations that can occur between the occipital bone and the transverse process of atlas vertebra.&#x0D; Material and methods: Five systematic search strings were conducted on PubMed database on 14.01.2022. The search was conducted by one observer to identify studies on PCP, and on ETP in living patients. Open and close access articles were selected as this topic is infrequently described in the main medical literature.&#x0D; Results: We provided with a pictorial review of 1) Paracondylar tubercle, 2) Unilateral PCP with cylindrical shape, 3) Unilateral PCP with pyramidal shape, 4) Unilateral PCP with lateral joint with transverse process, 5) Unilateral PCP with superior joint and partial fusion with transverse process, 6) Unilateral ETP with neo-condyle and joint with occipital condyle, 7) Unilateral ETP with joint with occipital bone, 8) Unilateral ETP with a bony bridge with lateral mass (ponticulus lateralis), and 9) Bilateral variation: paracondylar mass and ETP.&#x0D; Conclusions: Six figures were found in the selected literature and belong only to articles published in closed access. We provided with additional 41 open access freely available figures. We were first to present CBCT reference figures of: 1) Unilateral paracondylar tubercle, 2) Fusion of PCP with the transverse process of C1, 3) Joint between ETP and the lateral side of occipital condyle, and 4) Presence of bony bridge (ponticulus lateralis) between ETP and the lateral mass of C1. We were also first to describe a bilateral mixt variation with paracondylar mass on one side and ETP on the other side of C1. An open and accessible knowledge support (such as Nemesis journal) is needed to easily find clinical reference CBCT figures of craniocervicofacial bone variations.&#x0D;

Web in the Neck – An Interesting Case Report

Lateral neck masses are common in children, ranging from simple benign diseases to pathologies with malignant potential. Plexiform neurofibromas are extremely rare peripheral nerve sheath tumours involving multiple nerve sheath fascicles. They are typically seen in the paediatric population, with the majority affecting the craniofacial area and neck. Due to the close clinical and histological resemblance with other benign neck lesions such as lymphadenitis and branchial cysts, these cases can often go misdiagnosed. We describe a lesion in a young girl who presented with a progressive lateral neck swelling and how it was managed.