C2 Spinous Process Research Articles

Evaluation of Radiological and Anatomical Features of Cervical Vertebrae in Adult Persian Cat.

Radiographic studies of Persian cat's cervical vertebrae can provide us with valuable information used in identifying its anatomical features, investigating various species of Persian cats and evaluating their cervical pathologies. The present study aimed to investigate the anatomical and radiological features of cervical vertebrae in Persian cats to create a comprehensive and accurate reference for the normal range of cervical bones and joints that can be used for clinical decision-making and interpretation of radiographic findings in these cats. The present descriptive-cross-sectional study included 10 adult Persian cats, including 5 males and 5 females. All cats underwent radiography in the dorsoventral, ventrodorsal, left lateral and right lateral recumbency. Then, anatomical investigations were performed. According to our findings, Persian cats were different from other cat species in some cervical vertebral characteristics, which can be suggested as comparative anatomy in these species. The most important differences were as follows: the C3 and C7 had the lowest and highest spinous process height (SPH), respectively. The atlas had the highest transverse process width (TPW), which was significantly different with other cervical vertebrae (p ≤ 0.05). Moreover, the cervical vertebrae were not significantly different in vertical diameter of cranial vertebral foramen (VDCrVF) and transverse diameter of cranial vertebral foramen (TDCrVF) (p ≤ 0.05). The caudal surface of the atlantic vertebral arch had two dorsal and ventral tubercles. Also, the ventral crest of the axis was quite indistinct in the cranial part while becoming prominent in the caudal part. The C3 spinous process was a wide, small tubercle, while the C7 spinous process was extended vertically. Finally, the C6 transverse processes had a large ventrocranial tubercle forming a sagittal plate with cranial and caudal parts separated by a notch. The accurate and comprehensive standard ranges obtained from the present study can be used for the interpretation of imaging results, clinical decision-making, and finding the normal and abnormal sizes of the cervical vertebrae and their processes in Persian cats.

Anatomical validation of needle placement for cervical paraspinal mapping of the multifidus.

The paraspinal muscles are an important component of electrodiagnostic testing for radiculopathy. In the cervical region, a protocol for cervical paraspinal mapping assumes accurate placement of the electromyography (EMG) needle into the cervical multifidus. However, there is scant information regarding the accuracy of needle placement in that muscle. This study examines the accuracy of this protocol in sampling the intended multifidus muscle of cadavers. An experienced electromyographer directed needles to multifidus at C5, C7, and T2 spinous processes of 19 embalmed cadavers, and injected color dyes. Separately another examiner dissected the cadavers, noting whether the dye was in the correct location and whether its trajectory approached any "danger zones" of nerve, artery, or joint. The dye was in the multifidus muscle 100% of the time and hit the intended bony target in 79%, 73%, and 79% of C5, C7, and T2 insertions. No insertion was found in a danger zone. The results indicate modest accuracy for EMG needle placement as proposed in the clinical protocol. Clinical utility of this method requires more work including the establishment of norms, sensitivities, specificities, and clinical impact.

Effects of Limbs' Spasticity on Spinopelvic Alignment in Post-Stroke Patients: A Cross-Sectional Study.

Objectives: This study aimed to determine the impacts of upper and lower limb (UL and LL) spasticity and impairment on spinal alignment in chronic post-stroke patients. Methods: A total of 45 consecutive chronic post-stroke patients, 18 women and 27 men, from 18 to 70 years old who presented post-stroke hemiparesis were recruited in this cross-sectional study. The clinical assessment included the Modified Ashworth Scale (UL-MAS and LL-MAS spasticity), Upper Limb Motricity Index (UL-MI), FAST-UL, and Five Times Sit-to-Stand Test (5T-STS); the Associated Reaction Rating Scale was used to measure associated reactions in the hemiparetic UL, the plumb line distance from the spinous process of C7 on the sagittal (PL-C7s) and frontal plane (Pl-C7f), the kyphosis apex (PL-AK), and the spinous process of L3 (PL-L3). Angular measures of spinal alignment were measured by a Bunnell scoliometer™ (angle of trunk rotation-ATR) and a gravity-dependent inclinometer (inclination at C7-T1 and T12-L1). Results: In chronic post-stroke patients, there was found to be an association between the 5T-STS and PL-C7f (β = 0.41, p = 0.05) and the angle of inclination at T12-L1 (β = 0.44, p = 0.01). The FAST-UL correlated with PL-C7f (β = -0.41, p = 0.05), while the UL-MI correlated with this last parameter (β = -0.36, p = 0.04) and the ATR (β = -0.31, p = 0.05). The UL-MAS showed correlation with the ATR (β = 0.38, p = 0.01). Conclusions: The results lead to the possibility that, in chronic post-stroke patients, spinal misalignment on the frontal and sagittal plane is associated both with strength impairment and UL spasticity. The improvement or restoration of spinopelvic parameters can take advantage of therapeutic interventions targeted at motor improvement and spasticity reduction of the hemiparetic side.

Use of bone landmarks for assessing the safety of acupuncture on the posterior midline of the neck region

ObjectiveMany acupuncture acupoints are located on the posterior midline of the neck region. The needling depth for acupuncture is important for practitioners, and an unsafe needling depth increases the possibility of damage to the spinal cord and brainstem. Can the safety of acupuncture be assessed by examining bone structures? We focused on this aim to carry out this study.MethodsThe shortest distance from the posterior border of the foramen magnum to the line joining both upper ends of the posterior border of the mastoid process was measured on 29 skulls. Distances from the posterior border of the vertebral foramen to the tip of the spinous process and posterior tubercle of the atlas were measured and evaluated from 197 dry cervical vertebrae and 31 lateral cervical radiographs of patient subjects. The anatomic relationships of the vertebral canal with the external occipital protuberance, tip of the spinous process of the axis, tip of the posterior tubercle of the atlas, and upper end of the posterior border of the mastoid process were observed and evaluated via lateral cervical radiography.ResultsThe shortest distance from the foramen magnum to the line between the mastoid processes was 4.65±1.75 mm, and the distance from the superior border of the vertebral foramen of the atlas to the posterior tubercle was less than the distance from the inferior border. The distance from the superior border of the vertebral canal to the tip of the spinous process in C2-C7 was greater than the distance from the inferior border. The mean lengths of the superior border of the C2 spinous process and the inferior border of the C7 spinous process were greater than 21 mm and 31 mm, respectively. The line from the upper end of the posterior border of the mastoid process to the tip of the C2 spinous process or 10 mm deep to the tip of the C2 spinous process was posterior to the vertebral canal.ConclusionsOn the posterior midline of the neck region between the tip of spinous process of axis and external occipital protuberance, if the needle reaches the depth of the line between the upper end of posterior border of mastoid process and the tip of the spinous process of the axis, approximately 10 mm along the spinous process of the axis, the needle is in the safe region. The mean length of the C2-C7 spinous process is suitable to accommodate the needling depth of the adjacent acupoint. Bone structures can be used to effectively assess the safety of acupuncture on the posterior midline of the neck region.

Musculoskeletal Ultrasound to Identify Changes in Obliquus Capitis Inferior Muscle & Position of Atlas After a Manual Stretch

Introduction: Cervicogenic headache (CGH) is a prevalent condition caused by a disorder of the cervical spine that is commonly accompanied by neck pain and headaches. There is limited research regarding interventions benefiting CGH long-term. Interventions geared toward the suboccipital musculature may be used to improve CGH symptoms due to their anatomical connection to the cervical spine. Purpose: To determine if an isolated manual stretch of the obliquus capitis inferior will create a change in muscle diameter and length and position of atlas relative to axis. Methods: This quasi-experimental study used a single group of 36 subjects. Pre- and post-test measurements of the muscle diameter and length of the obliquus capitis inferior and the distance between atlas and axis were obtained using musculoskeletal ultrasound before and after our manual stretching intervention. Results: The results showed a significant increase in both measures, indicating increased length of the right Obliquus Capitis Inferior and the distance between the transverse process of C1 and spinous process of C2 after the manual stretch was applied. The average width of the right Obliquus Capitis Inferior was found to be 1.01 cm prior to applying the manual stretch and 1.99 cm after applying the manual stretch, demonstrating an increase in the width of the R OCI pre- and post-stretch. Conclusion: The results of this study indicate that the application of a manual static stretch held for 2x30 seconds will produce and immediate and significant increases in muscle length and width of the right Obliquus Capitis Inferior. Further research should be conducted to establish validated stretching parameters targeting the suboccipital muscles and further examine the effects of these muscles on CGH symptoms

Prevalence of bifidity of the seventh cervical vertebral spinous process in southwestern Nigeria: a computed tomography based study

Palpation of the seventh cervical vertebra (C7) is an important landmark for counting vertebrae for vertebral spine surgical instrumentation. However, studies have shown that the spinous process of C7 displays an anatomical deviation among individuals, which may mislead a surgeon who is not aware of this, and there have been no such studies among southwest Nigerians. The present study aimed to examine the incidence of bifidity in the C7 spinous process and their variation among 48 subjects with the aid of a three-dimensional (3D) computed tomography. The 48 subjects who had undergone cervical spine computed tomography studies comprised the pooled data of ages between 12 and 55 years of black race in southwest Nigeria from the radiology department of the Trauma and Surgical Centre, Ondo State, Nigeria. A series of multivariate and discriminant statistical tests were performed on the measurement data to determine the occurrence of bifid spinous processes at C7 in southwestern Nigeria. The results show about 10% bifidity in the C-7 vertebra and no bifidity in the first cervical vertebra and the highest rate in the C-6 vertebra in the study population. The incidence in this study is significantly higher than findings in previous works. Thus, there is a need for clinicians to pay more attention to this variation when using C7 as a landmark especially in the studied population.

CT-navigated C2 Pedicle Screw insertion using dynamic reference array on C2 spinous process: A Novel Technique

ntroduction: Spine surgeons have endeavoured to improve the accuracy of pedicle screw insertion. Computed tomography (CT) guided navigation has been helpful in precisely passing pedicle screws even further accurately but, there were shortcomings noted with the technique due to movement between reference frame and anatomical landmarks, especially in the cervical spine which led to injury of vital neurovascular structures. Thus, there was a need for developing a technique which would eliminate the inherent error due to movement in the vertebral body while passing screws. Research Question: Can using C2 spinous process as an attachment for the reference array improve accuracy of C2 pedicle screws. Material and Methods: We prospectively studied data of 10 patients (20 screws) in whom Computed tomography navigated C2 pedicle screws insertion was carried out using the reference array on C2 spinous process. Accuracy of pedicle screws were confirmed by post instrumentation Computed tomography scan immediately intra operatively. Results: With the presented technique overall breach rate was 5% with one screw having a medial breach of grade 1 with no incidence of neurovascular injury or need for further revision. Discussion and Conclusion: Results from this study shows better accuracy than other techniques described to pass C2 pedicle screws eliminating the error in movement from the cervical vertebrae and the reference frame being nearest to the C2 pedicle. Although there is a learning curve with the adoption of the navigation system, with experience, the challenges associated with Cervical pedicle screws (CPS) insertion can be overcome.

Analysis of risk factors for axial symptoms after posterior cervical open-door laminoplasty

BackgroundLaminoplasty (LP), a procedure commonly used to treat cervical spondylotic myelopathy (CSM), often results in the development of axial symptoms (AS) postoperatively. This study aims to analyze the risk factors associated with the occurrence of AS after LP.MethodsWe collected and evaluated clinical data from 264 patients with CSM who underwent LP treatment at our institution from January 2018 to January 2022 through a single-center retrospective study. Of the patients, 153 were male and 111 were female, with an average age of 58.1 ± 6.7 years. All patients underwent C3-7 posterior laminoplasty. Based on the occurrence of postoperative axial symptoms, the patients were divided into an AS group and a non-AS group. General information, including age, gender, disease duration, Japanese Orthopaedic Association (JOA) score, postoperation early function training, and collar-wearing time, was recorded and compared between the two groups. Surgical-related data, such as operative segments, surgical time, intraoperative blood loss, intraoperative facet joint destruction, and destruction of the C7 spinous process muscle insertion, were also compared. Imaging data, including preoperative cervical curvature, cervical range of motion, preoperative encroachment rate of the anterior spinal canal, and angle of laminar opening, were collected. Univariate and multivariate logistic regression analyses were used to identify risk factors for the development of AS after LP, and receiver operator characteristic (ROC) curves were utilized to explore the optimal preoperative parameters.ResultsAll 264 patients successfully underwent surgery and were followed up for an average of 19.5 ± 6.8 months. At the 6-month follow-up, 117 patients were diagnosed with AS, resulting in an incidence rate of 40.2%. The multivariate logistic regression analysis identified that preoperative encroachment rate of anterior spinal canal (Pre-op ERASC), intraoperative facet joints destruction (Intra-op FJD), intraoperative open-door angle (Intra-op OA), destroy the C7 spinous process muscle insertion (Destroy C7 SPMI), postoperative loss of cervical curvature (Post-op LCC), and postoperative loss of cervical range of motion (Post-op LCROM) were independent risk factors for AS. Conversely, preoperative cervical curvature (Pre-op CC) and postoperation early function training (Post-op EFT) were protective factors against AS. According to the ROC curve, the cutoff values for preoperative anterior spinal canal occupation rate and preoperative cervical curvature were 28.5% and 16.5°, respectively. When the preoperative anterior spinal canal occupation rate was greater than 28.5% or the preoperative cervical curvature was less than 16.5°, AS was more likely to occur after surgery.ConclusionHigh preoperative anterior spinal canal occupation rate, facet joint damage during surgery, C7 spinous process muscle stop point damage, larger angle of laminar opening, and greater postoperative cervical curvature loss and cervical range of motion loss are associated with an increased risk of developing AS after cervical laminoplasty. Conversely, a larger preoperative cervical curvature and early postoperative functional exercises can help reduce the occurrence of AS.

Anatomical study and proposed EMG technique for the cervical paraspinal muscles.

Paraspinal electromyography has proven to be the most sensitive component of the electrodiagnostic examination for lumbar spinal disorders. However, no standardized, anatomically validated technique has been proposed for the cervical region. This study reviewed the published textbooks on cervical paraspinal anatomy to develop a standardized electromyography technique and scoring system. A library search found 32 anatomy texts published between 2000 and 2021. Of these 11 were unique and appropriate. Most texts described the basic muscle anatomy similarly, but only one cited original research. When the spinous process is defined as the origin, the multifidus and deeper rotatores appear innervated by the posterior primary rami of single cervical roots. However, texts differ in the number of pennae, between two and five, traveling to transverse process regions below. These are crowded into a small area between the spinous processes and transverse processes. Based on this understanding, a proposed cervical paraspinal mapping technique involves skin insertions from 1 to 2 cm lateral to the C5, C7, and T2 spinous processes. The needle samples transversely and deep toward midline, contacts bone, then is withdrawn and redirected to sample medial and caudally to midline to bone, creating two scores of 0-4 at three levels, theoretically resulting in scores of 0-24. This technique must be validated by clinical research to determine the range of normal, reproducibility, and the spectrum of findings in various disorders.

Axial Neck Pain after Cervical Laminoplasty with Preserving C7 Spinous Process Using C7 Arcocristectomy: A Prospective Study.

Single-blinded, randomized, single-center, prospective study. This study aims to compare the radiographical and clinical outcomes between C7 laminoplasty and C7 arcocristectomy, which preserves the C7 spinous process. Laminoplasty is a widely used surgical method that decompresses the cervical spinal cord. However, axial neck pain is one of the major factors of dissatisfaction, and still, it is not clearly solved the reduction method of postoperative axial neck pain. Thirty-one patients with multilevel cervical spondylotic myelopathy who required C6-C7 level decompression surgery were operated and followed up for 24 months. One group (15 patients) received C7 arcocristectomy without laminoplasty, and the other group (16 patients) received C7 laminoplasty. Flexion, neutral, and extension angles were measured using the Cobb method at C2-C7 to evaluate preoperative and postoperative radiographic parameters. Range of motion (ROM), ROM preservation rate of the cervical spine, C2-C7 sagittal vertical axis (SVA), and T1 slope were measured using C-spine lateral X-ray. The Visual Analog Scale (VAS) and modified Japanese Orthopedic Association (JOA) score were used to compare preoperative and postoperative clinical symptoms. Flexion, neutral, extension angles of the cervical spine, C2-C7 SVA, T1 slope, ROM, ROM preservation rate, and modified JOA score were not significantly different between the two groups (p>0.05). In the C7 arcocristectomy group, the average postoperative VAS for axial neck pain was increased in 13.3% (2/15) of the patients, whereas in the C7 laminoplasty group, the average postoperative VAS was increased in 43.8% (7/16) of the patients (p=0.018). C7 arcocristectomy, which preserves the C7 spinous process and posterior structures, is a useful technique for relieving axial neck pain.

Morphological analysis of C2-C7 spinous process bifurcation in Chinese population: a study using three-dimensional reconstruction of computed tomography.

This study aimed to investigate the anatomical morphology of the C2 to C7 spinous process (SP) bifurcation (SPB) in the Chinese population and reveal its potential clinical significance. Measurement parameters of the three-dimensional (3D) reconstructions of neck computed tomography scans (n = 92 scans) were retrospectively analysed. The 3D reconstruction and measurements were performed using Mimics Research 19.0 and 3-Matic Research 11.0. Two independent investigators reviewed all the data, including parameters such as the length and angle of the SPB. The effects of age and sex were also analysed. We identified four morphological types of SPB: fully bifid (n = 252, 45.65%), partially bifid (n = 65, 11.78%), non-bifid (n = 226, 40.94%) and unilateral branch (n = 9, 1.63%). The Kappa coefficients indicated good inter-observer reproducibility (0.776), and the intraclass correlation coefficients (ICC) values demonstrated excellent intra-rater reliability (ICC = 0.9, p < 0.0001) in the classification and measurement of SPB parameters. The percentage of general bifid SP was more than 70% in C2-5 and about 21% in C6, while all C7 SPs presented non-bifid. Morphology was symmetrical in bifid and partially bifid SP, while unilateral SP was not. The classification system of SPB in this study proved consistent and reliable, despite the subjective bias. Identifying the cervical level by C6 bifurcation is unreliable, as nearly 80% of C6 SP is non-bifid. Our work provides an accurate and effective anatomical reference for SPB studies in the Chinese population.

An Orientational Harvesting Occipital Artery Technique via far Lateral Approach: A Cadaveric Study

To provide further information on the identification of the occipital artery (OA) and suggest an improved approach to its anterograde dissection technique for harvesting. Six cadaveric specimens were prepared for surgical simulation, and the anterograde approach was used to harvest the OA; a hockey stick incision was made from the C2 spinous process through the nuchal ligament to the mastoid tip. By retracting the scalp flap from the posterior arch of C2 to the transverse process, the suboccipital triangle was reflected by a single myocutaneous flap from the inferior nuchal line. In addition, 70 head computed tomography angiography scans were assessed bilaterally (n= 140) to study the running pattern of the OA. The mean total length of the mobilized OA was 11.8 ± 0.7cm, with a diameter of 1.5 ± 0.1-2.1 ± 0.2mm at the suboccipital segment and 1.3 ± 0.1mm at the upper edge of the surgical incision. The average distance of OA at the inferior nuchal line to the midline was 2.9 ± 0.3cm, the average distance of OA at the superior nuchal line to midline was 4.1 ± 0.2cm, the average distance of OA at incision edge to midline was 5.2 ± 0.3cm. Orientational anterograde technique for OA harvesting is a fast and easy approach. This approach avoids critical neurovascular structures. The most important step is to identify the OA near the lateral edge of the superior oblique muscle. Subsequently, in conjunction with preoperative computed tomography angiography, an imaginary line that crosses the inferior and superior nuchal lines may be established to assist in the separation of theOA.

Impact of C3 laminectomy on cervical sagittal alignment in cervical laminoplasty: a prospective, randomized controlled trial comparing clinical and radiological outcomes between C3 laminectomy with C4–C6 laminoplasty and C3–C6 laminoplasty

Background ContextC3 laminectomy in cervical laminoplasty is a modified laminoplasty technique that can preserve the semispinalis cervicis muscle attached to the C2 spinous process. Several previous studies have shown that this technique can lead to better outcomes of postoperative axial neck pain and C2–C3 range of motion (ROM) than conventional cervical laminoplasty. However, there is still a lack of understanding of total and proportional postoperative cervical sagittal alignment outcomes. PurposeTo assess the effects of C3 laminectomy in cervical laminoplasty on postoperative cervical alignment and clinical outcomes. DesignA single-center, patient-blinded, randomized controlled trial. Patient SampleWe included consecutive 126 patients diagnosed with cervical spondylotic myelopathy (CSM) or ossification of posterior longitudinal ligament (OPLL) who were scheduled for cervical laminoplasty from March 2017 to January 2020. Outcome MeasuresThe primary outcome measures were C2–C7 Cobb angle (CA) and neck disability index (NDI). Secondary outcomes measures included other clinical outcomes and radiographic parameters including segmental Cobb angle and presence of C2–C3 interlaminar fusion. MethodsPatients were randomly allocated to either the C3 laminectomy with C4–C6 laminoplasty group (LN group) or the C3–C6 laminoplasty group (LP group) at a 1:1 ratio. Laminoplasty was performed using a unilateral open-door technique and stabilized with titanium mini plates. A linear mixed model analysis was employed to examine the longitudinal data from postoperative 1-year through 3-year. Additional analysis between three types of cervical sagittal alignment morphology was done. ResultsAmong 122 patients who were randomly allocated to one of two groups (LN group, n=61; LP group, n=61), modified intent-to-treat analysis was done for 109 patients (LN group, n=51, LP group, n=58) who had available at least a year of postoperative data. Postoperative C2–C7 CA was not significantly different between the two groups. However, NDI was significantly different between the two groups (12.8±1.0 in the LN group vs 8.6±1.0 in LP group, p=.005), which exceeded the minimum clinically important difference (MCID). The postoperative C2–C3 CA was significantly greater in the LN group (7.1±0.5° in LN group vs 3.2±0.5° in LP group, p<.001) while C4–C7 CA was significantly smaller in the LN group (3.9±0.8° in LN group vs 7.7±0.7° in LP group, p<.001) with greater cSVA in the LN group (31.6±1.4 mm in LN group vs 25.5±1.3 mm in LP group at postoperative 3-year, p=.002). Postoperative Euro-Quality of Life-5 Dimension (EQ-5D), numerical rating scores for neck pain (NRS-N) were significantly better in the LP group than in the LN group (all p<.05) and only EQ-5D surpassed the MCID. The C2-C3 fusion rate was significantly different between the LN group (9.8%) and the LP group (44.8%) (p<.001). The LN group showed a higher prevalence of a specific cervical alignment morphology characterized by a sigmoid shape with proximal lordosis and distal kyphosis (S curve). This S curve demonstrated significantly unfavorable outcomes across multiple outcome variables. ConclusionThe impact of C3 laminectomy in cervical laminoplasty on postoperative kyphosis among patients with CSM or OPLL did not significantly differ from that of C3–C6 laminoplasty. However, C3 laminectomy in cervical laminoplasty might result in an unfavorable clinical outcome with an unbalanced cervical sagittal alignment characterized by a sigmoid shape with proximal lordosis and distal kyphosis.

Evaluation of intraoperative coronal alignment using a computer-assisted rod bending system (CARBS) without intraoperative radiation exposure in adult spinal deformity surgery: a technical note and preliminary results.

Intraoperative radiographs and fluoroscopy are used in adult spinal deformity (ASD) surgery to prevent postoperative coronal malalignment but with limited accuracy. Therefore, we applied a computer-assisted rod bending system (CARBS: Bendini®) for an intraoperative coronal alignment evaluation. The purpose of this study is to introduce this novel technique and validate its accuracy. Fifteen ASD patients were included in the study. The heads of the bilateral S1 pedicle screws (S1), the S1 spinous process, and the bilateral greater trochanter (GT) and the C7 spinous process were recorded with CARBS for an intraoperative coronal alignment evaluation. The lines which connect the bilateral S1 and GT were used as references. The C7-center sacral vertical line (C7-CSVL) on the CARBS monitor was checked, and the C7-CSVL from the intraoperative CARBS recording and postoperative standing whole spine radiograph were compared. Intraoperative C7-CSVL with CARBS was 35.1 ± 31.6mm when the S1 pedicle screws were used as the reference line and was 16.6 ± 17.8mm when the GTs were used. Postoperative C7-CSVL by radiograph was 15.1 ± 16.5mm. In addition, the intraoperative C7-CSVL with CARBS and the postoperative C7-CSVL showed a strong positive correlation in both GT (R = 0.86, p < 0.01) and in S1(R = 0.79, p < 0.01), with a better correlation found in GT than in S1. Intraoperative C7-CSVL with CARBS was found to be highly accurate in ASD surgery. Our results suggest that this novel technique can be useful as an alternative to intraoperative radiography and fluoroscopy and may reduce radiation exposure.

Relation between Photogrammetry and Spinal Mouse for Sagittal Imbalance Assessment in Adolescents with Thoracic Kyphosis.

The evaluation of postural alignment in childhood and adolescence is fundamental for sports, health, and daily life activities. Spinal Mouse (SM) and photogrammetry (PG) are two of the most debated tools in postural evaluation because choosing the proper instrument is also important to avoid false or misleading data. This research aims to find out the best linear regression models that could relate the analytic kyphosis measurements of the SM with one or more PG parameters of body posture in adolescents with kyphotic posture. Thirty-four adolescents with structural and non-structural kyphosis were analyzed (13.1 ± 1.8 years; 1.59 ± 0.13 m; 47.0 ± 12.2 kg) using SM and PG on the sagittal plane in a standing and forward-bending position, allowing us to measure body vertical inclination, trunk flexion, and sacral inclination and hip position during bending. The stepwise backward procedure was assessed to estimate the variability of the grade of inclination of the spine and thoracic spine curvature with fixed upper and lower limits, evaluated with SM during flexion. In both models, the PG angle between the horizontal line and a line connecting the sacral endplate-C7 spinous process and the PG hip position were the best regressors (adjusted-R2 SM bend = 0.804, p < 0.001; adjusted-R2 SM fixed bending = 0.488, p < 0.001). Several Spinal Mouse and photogrammetry parameters showed significant correlations, especially when the Spinal Mouse measurements were taken when the adolescents were in the forward-bending position. Physicians and kinesiologists may consider photogrammetry as a good method for spinal curve prediction.

Regional variations in C1–C2 bone density on quantitated computed tomography and clinical implications

BackgroundOur elderly population is growing and the number of spine fractures in the elderly is also growing. The elderly population in general may be considered as poor surgical candidates experience a high rate of fractures at C1 and C2 compared with the general population. Nonoperative management of upper cervical fractures is not benign as there is a high nonunion rate for both C1 and C2 fractures in the elderly, and orthosis compliance is often suboptimal, or complicated by skin breakdown. The optimal technique for upper cervical stabilization in the elderly may be different than in younger populations as the bone quality is inferior in the elderly. The objective of this basic science study is to determine whether the bone mineral density (BMD) of C1 and C2 vary by region, and if this is a gender difference in this elderly age group. MethodsTwenty cadaveric spines from 45 to 83 years of age were used to obtain BMD using quantitated computed tomography (QCT). BMD was measured using a QCT. For C1, 8 regions were determined: anterior tubercle, bilateral anterior and medial lateral masses, bilateral posterior arches, and posterior tubercle. For C2, 7 regional BMDs were determined: top of odontoid, base of odontoid-body interface, mid body, bilateral lateral masses, anterior inferior body near the discs space, and the C2 spinous process. ResultsThe BMD was greatest at the C1 anterior tubercle (564.4±175.8 mg/cm3) and C1 posterior ring (420.8±110.2 mg/cm3), and least at the anterior and medial lateral masses (262.8±59.5 mg/cm3, 316.9±72.6 mg/cm3). At C2 QCT BMD was greatest at the top of the dens (400.6±107.9 mg/cm3) decreasing down through the odontoid-C2 body junction (267.8±103.5 mg/cm3) and least in the mid C2 body 249.1±68.8 mg/cm3). The posterior arch of C1 and the spinous process of C2 had higher BMD's 420.8±110.2 mg/cm3 and 284.1±93.0 mg/cm3, respectively. A high correlation was observed between the BMD at the interface of the dens-vertebral body with the vertebral body with a Pearson correlation coefficient of 0.86. The BMD of the top of dens was significantly higher (p<.05) than all the regions in C2. ConclusionsRegional and segmental BMD variations at C1 and C2 have clinical implications for surgical constructs in the elderly population. Given the higher BMDs of the C1 and C2 spinous process and posterior arches, consideration should be given to incorporate these areas using various C1–C2 wiring techniques. In the elderly, lateral masses particularly at C1 with lower BMD may result in potential screw loosening and nonunion in this age group. Old-school wiring techniques have a track record of efficacy and safety with less blood loss, reduced operative time, reduced X-ray exposure, and should be considered in the elderly as a primary stabilization technique or a belt-over suspenders approach based on regional variations in BMD in the elderly.

Test-retest reliability of a photographic marker-based system for postural examination.

The BHOHB system (Bhohb S.r.l., Italy) is a portable non-invasive photographic marker-based device for postural examination. To assess the test-retest reliability of the BHOHB system and compare its reliability with an optoelectronic system (SMART-DX 700, BTS, Italy). Thirty volunteers were instructed to stand upright with five markers on the spinous processes of C7, T6, T12, L3 and S1 vertebrae to define the dorsal kyphosis and lumbar lordosis (sagittal plane) angles. Three markers were placed on the great trochanter, apex of iliac crest and lateral condyle of the femur to detect pelvic tilt. Finally, to define angles between the acromion and the spinous processes (frontal plane), two markers were placed on the right and left acromion. Postural angles were recoded simultaneously with BHOHB and optoelectronic systems during two consecutive recording sessions. The BHOHB system revealed excellent reliability for all the angles (ICCs: 0.92-0.99, SEM: 0.78∘-3.33∘) as well as a shorter processing time compared to the optoelectronic system. Excellent reliability was also found for all the angles detected through the optoelectronic system (ICCs: 0.91-0.99, SEM: 0.84∘-2.80∘). The BHOHB system resulted as a reliable non-invasive and user-friendly device to monitor spinal posture, especially in subjects requiring repeat examinations.

Quantitatively biomechanical response analysis of posterior musculature reconstruction in cervical single-door laminoplasty

Background and objectiveThe current trend of laminoplasty is developing toward the goal of muscle preservation and minimum tissue damage. Given this, muscle-preserving techniques in cervical single-door laminoplasty have been modified with protecting the spinous processes at the sites of C2 and/or C7 muscle attachment and reconstruct the posterior musculature in recent years. To date, no study has reported the effect of preserving the posterior musculature during the reconstruction. The purpose of this study is to quantitatively evaluate the biomechanical effect of multiple modified single-door laminoplasty procedures for restoring stability and reducing response level on the cervical spine. MethodsDifferent cervical laminoplasty models were established for evaluating kinematics and response simulations based on a detailed finite element (FE) head-neck active model (HNAM), including ① C3 – C7 laminoplasty (LP_C37), ② C3 – C6 laminoplasty with C7 spinous process preservation (LP_C36), ③ C3 laminectomy hybrid decompression with C4 – C6 laminoplasty (LT_C3 + LP_C46) and ④ C3 – C7 laminoplasty with unilateral musculature preservation (LP_C37 + UMP). The laminoplasty model was validated by the global range of motion (ROM) and percentage changes relative to the intact state. The C2 – T1 ROM, axial muscle tensile force, and stress/strain levels of functional spinal units were compared among the different laminoplasty groups. The obtained effects were further analysed by comparison with a review of clinical data on cervical laminoplasty scenarios. ResultsAnalysis of the locations of concentration of muscle load showed that the C2 muscle attachment sustained more tensile loading than the C7 muscle attachment, primarily in flexion-extension (FE) and in lateral bending (LB) and axial rotation (AR), respectively. Simulated results further quantified that LP_C36 primarily produced 10% decreases in LB and AR modes relative to LP_C37. Compared with LP_C36, LT_C3 + LP_C46 resulted in approximately 30% decreases in FE motion; LP C37 + UMP also showed a similar trend. Additionally, when compared to LP_C37, LT_C3 + LP_C46 and LP C37 + UMP reduced the peak stress level at the intervertebral disc by at most 2-fold as well as the peak strain level of the facet joint capsule by 2–3-fold. All these findings were well correlated with the result of clinical studies comparing modified laminoplasty and classic laminoplasty. ConclusionsModified muscle-preserving laminoplasty is superior to classic laminoplasty due to the biomechanical effect of the posterior musculature reconstruction, with a retained postoperative ROM and loading response levels of the functional spinal units. More motion-sparing is beneficial for increasing cervical stability, which probably accelerates the recovery of postoperative neck movement and reduces the risk of the complication for eventual kyphosis and axial pain. Surgeons are encouraged to make every effort to preserve the attachment of the C2 whenever feasible in laminoplasty.

Median trans-atlanto-occipital membrane microsurgical approach to the posterior cranial fossa without craniotomy.

Minimally invasive approaches are becoming increasingly popular and contributing to improving the results of the surgical treatment of a wide variety of intracranial pathologies. Fifteen patients with posterior cranial fossa tumors underwent microsurgery through the atlanto-occipital membrane without resection of any bone structures. Tumors were localized in the brainstem in 8 patients and in the fourth ventricle in 7 patients. According to preoperative MRI and CT scans, the distance between the posterior arch of the atlas and the opisthion ranged from 9.9 to 16.5 mm (median 13 mm). The surgery was performed with the patient in the prone position and the head flexed. The trajectory of the surgical approach was directed from the skin incision located above the C2 spinous process 3.5-4 cm rostral along the midline. Total tumor resection was performed in 10 patients, subtotal resection in 2 patients, partial resection in 1 patient, and open biopsy in 2 patients. Surgical complications occurred in only 1 patient (meningoencephalitis). This minimally invasive trans-atlanto-occipital membrane approach for posterior cranial fossa tumors provides adequate visualization of the caudal part of the fourth ventricle and brainstem when the anthropometric parameters of the patient are suitable.

Assessment of Spinal Motion in Young Adults (15 to 26 Years of Age) Without Spine Deformity Using Inertial Sensor and Manual Measurements

Introduction: The evaluation of spinal range of motion is paramount in the context of spinal disorders, especially considering emerging surgical techniques focused on motion preservation and circumventing spinal fusion. Manual measurement techniques, which utilize a goniometer and tape measure, demand proficiency to accurately assess spinal motion. This becomes further complicated in patients with spinal deformities. Inertial sensors emerge as a potential clinical solution. By assessing electronic inertial sensor performance in capturing thoracolumbar spinal range of motion, this study evaluates the level of association observed between the range of motion measurements captured by manual and sensor methods. Methods: Participants included 19 healthy young adults (74% female, average age 20 years [range 15-26]) without spinal conditions. Each performed a series of manual spinal motion evaluations quantified using a standard goniometer and a tape measure. Participants repeated the motions with an electronic inertial sensor attached to their C7 spinous process. Each manual and electronic motion sequence was performed three times. Data were analyzed with a Pearson’s correlation to assess congruence between the datasets, and a paired t-test compared the mean values between the two groups to examine the two motion measurement methodologies. Results: Association between the different planes of motion for manual and electronic repeated clinical motions were moderate (r=0.44) to strong (r=0.70). Manual measurements showed similar levels of variation to that of the electronic measurements. Upon comparing the manual and electronic measurement sets through a paired t-test, the mean values exhibited no statistically significant differences. Conclusion: The electronic motion measurements were congruent with manual measurements based on the correlation values and t-tests presented. Thus, inertial sensors can approximate the measurements of manual methods in assessing spinal range of motion. This demonstrates the potential for clinical adaptation of these sensors into spine centers to objectively assess patient outcomes in spinal motion preserved surgeries.