Applied anatomy and surgical technique of the lateral single-position L5-S1 fusion.

The latest development in the anterior lumbar interbody fusion (ALIF) procedure is its application in the lateral position to allow for simultaneous posterior percutaneous screw placement. The technical details of the lateral ALIF technique have not yet been described. To describe the surgical anatomy relevant to the lateral ALIF approach we performed a comprehensive anatomical study. In addition, the preoperative imaging, patient positioning, planning of the skin incision, positioning of the C-arm, surgical approach, and surgical technique are discussed in detail. The technique described led to the successful use of the lateral ALIF technique in our clinical cases. No lateral ALIF procedure needed to be aborted during these cases. Our present work gives detailed anatomical background and technical details for the lateral ALIF approach. This teaching article can provide readers with sufficient technical and anatomical knowledge to assist them in performing their first lateral ALIF procedure.

Producing 3D printed high-fidelity retroperitoneal models from in vivo patient data: The Oxford Method.

Macroscopic anatomy has traditionally been taught using cadaveric material, lectures and a variable amount of additional resources such as online modules. Anatomical models have also been used to assist in teaching. Of these, traditional plastic models have been shown to be effective educational tools, yet have significant drawbacks such as a lack of anatomical detail and texturisation. Three-dimensional (3D) printed models stand to solve these problems and widen access to high-quality anatomical teaching. This paper outlines the use of 3D multi-planar imaging (CT and MRI) as a framework to develop an accurate model of the retroperitoneum. CT and MRI scans were used to construct a virtual 3D model of the retroperitoneum. This was printed locally as a full-size colour model for use in medical education. We give a complete account of the processes and software used. This study is amongst the first of a series in which we will document the newly formed Oxford Library of Anatomy. This series will provide the methodology for the production of models from CT and MRI scans, and the Oxford Library of Anatomy will provide a complete series of some of the most complex anatomical areas and ones which degrade quickly when a real cadaver is being used. In our own internal experience, the models are highly accurate, reproducible and durable, as compared to prosected specimens. We hope they will form an important adjunct in the teaching of the subject.

Association Among Dyskinesia of the Lumbar Spine Segment, Inclination Angle of the Lumbosacral Spine, and Low Back Pain in Young Athletes: A Predictive Correlational Study.

OBJECTIVE: This predictive correlational study aimed to investigate the association among low back pain (LBP), dyskinesia of the lumbosacral spine segment (determined by inertial sensors), and inclination angles: the inclination angle of the lumbosacral spine (alpha), the inclination angle of the thoracolumbar spine (beta), and the inclination angle of the upper thoracic section (gamma). Our hypothesis was that young athletes with LBP had a particular dyskinesia: nonphysiological movements of the lumbosacral segment of the spine. METHODS: The study group consisted of 108 young athletes aged 10 to 16 years (male/female 44%/56%; 12.3 ± 1.8 years; 160.1 ± 12.0 cm; 51.1 ± 13.8 kg; 4.3 ± 2.4 training years; 3.7 ± 2.1 training h/wk). The alpha, beta, and gamma angles were measured with a digital inclinometer. The position of the lumbosacral segment at the maximum extension was determined with the inertial sensors, positioned at the 11th thoracic vertebra (T11), the third lumbar spine vertebra (L3), and the second sacral spine vertebra (S2). The data were analyzed using Student's t tests, tetrachoric correlation coefficients, and logistic regression. RESULTS: There was a significant statistical difference in alpha angles (t = 9.4, P < .001) and lumbar positions in extension (t = 6.4, P < .001) between groups with LBP and without LBP. The logistic regression indicated that LBP in young athletes was significantly associated with the increased alpha angle and nonphysiological lumbar position in extension measured by a sensor at the third lumbar spine vertebra. CONCLUSION: There was a strong association among LBP, increased inclination angle of the lumbosacral spine, and dyskinesia of the lumbar spine segment in young athletes.

The sacral screw placement depending on morphological and anatomical peculiarities.

PURPOSE: Various pathologies of the lumbosacral junction require fusion of the L5/S1 segment. However, pseudarthroses, which often come along with sacral screw loosening, are problematic. The aim of the present investigation was to elaborate the morphological features of the L5/S1 segment to define a so-called "safe zone" for bi- or tricortical screw placement without risking a damage of the iliac vessels. METHODS: A total of one hundred computed tomographies of the pelvis were included in this investigation. On axial and sagittal slices, pedicle morphologies, the prevertebral position of the iliac vessels, the spinal canal and the area with the largest bone density were analyzed. RESULTS: Beginning from the entry point of S1-srews iliac vessels were located at an average angle of 7° convergence, the spinal canal at 38°. Bone density was significantly higher centrally with a mean value of 276 Hounsfield Units compared to the area of the Ala ossis sacri. The largest intraosseous screw length could be achieved at an angle of 25°. The average pedicle width was 20 mm and the pedicle height 13 mm. CONCLUSIONS: A "safe-zone" for bicortical screw placement at S1 with regard to the course of the iliac vessels could be defined between 7° and 38° convergence. Regarding the area offering the largest bone density and the maximal possible screw length, a convergence of 25° is recommended at S1 to reduce the incidence of screw loosening. Screw diameter, as a further influence factor on screw holding, is limited by pedicle height not pedicle width.

Sagittal Spinal Morphotype Assessment in Dressage and Show Jumping Riders.

CONTEXT: Previous research has analyzed how the sport influences sagittal spinal curvatures in young athletes and has found that spinal curves may be modified as a consequence of repeated movement patterns and postures of each discipline. OBJECTIVE: To analyze sagittal spinal alignment by equestrian discipline and its relation to training load, and to describe "sagittal integrative morphotype" in young riders. DESIGN: Observational descriptive study. SETTING: Training room. PARTICIPANTS: A total of 23 riders (aged 9-17 y)-13 dressage riders (3 males and 10 females) and 10 show jumping riders (5 males and 5 females)-participated voluntarily. MAIN OUTCOME MEASURES: Mann-Whitney U test was applied to determine differences between riders' characteristics (gender, discipline, and training load) and spine variables. RESULTS: According to normality ranges for spinal curves, females showed an increase for lumbar curvature in standing position. It was found that show jumping riders manifested an increment in thoracic and lumbar curves while standing and an increase in the thoracic curvature in slump sitting. Statistically significant differences were found when lumbar curvature, "sit and reach" distance, and lumbo-horizontal angle in flexion were analyzed by gender in "sit and reach" test. No statistical significant differences were found when spinal curves in each position were analyzed depending on the training load. With regard to "sagittal integrative morphotype," all riders presented a hyperkyphotic dorsal morphotype no matter what their discipline. As for the lumbar curve, dressage and show jumping riders presented a functional hyperkyphotic morphotype. CONCLUSIONS: It is important to note that many riders presented a sagittal imbalance for the thoracic and lumbar curves. Therefore, as the sagittal spinal misalignments persist and worsen over time, exercise programs to prevent or rehabilitate these imbalances in young riders will be needed. The "sagittal integrative morphotype" assessment is an essential tool in order to identify the spinal misalignment.

3D vascular anatomy of the presacral space: impact of age and adiposity.

INTRODUCTION AND HYPOTHESIS: Defining patient characteristics that alter vascular anatomy at the sacrum is critical for avoiding life-threatening bleeding at the time of sacrocolpopexy. We tested the hypothesis that in thinner/older women, the bifurcations of the aorta and inferior vena cava (IVC) are lower relative to S1 resulting in less space accessible for suture/mesh placement, placing this group at increased risk of major vascular injury. METHODS: In a retrospective cross-sectional study, CT scans were used to make 2D measurements and a 3D model of the aorta/IVC, intervertebral disc space, and bony anatomy using segmentation and modeling software. For analysis, Spearman's and Pearson's correlation, Student's t test and the Mann-Whitney U test were used along with multivariate analysis of variance. RESULTS: Of eligible women who had undergone abdominal/pelvic CT, 107 were included. The median locations of the aortic and IVC bifurcations utilizing 2D analysis were at the inferior L4 and middle L5 vertebral body, respectively. In 10.2% of patients, the IVC was located at the L5-S1 disc space or lower; however, 3D modeling of this space which allowed assessment of the area below the S1 "drop off" showed that the amount of accessible space for suture/mesh placement was not decreased. Utilizing 2D analysis there was no statistically significant independent correlation between age or adiposity and the aortic or IVC bifurcation. Patients who were both elderly and thinner had a lower aortic bifurcation (p = 0.005) and a trend towards a lower IVC bifurcation (p = 0.082). CONCLUSIONS: In 10.2% of women, the IVC bifurcation descended at or below the L5-S1 disc space, suggesting that this group of women is at increased risk of major vascular injury. Patients who were both thin and elderly had lower bifurcations, but there was no difference in accessible surface area for suture placement on 3D analysis. 3D modeling improved visualization of the anatomy beyond the S1 "drop off" and may provide a future tool for surgical planning once predictors of high-risk anatomy are defined.

Optimal axis for lumbosacral interbody fusion: Prospective finite element analysis and retrospective 3D-CT measurement.

A feasible and optimal axis of biomechanical and anatomic significance in axial lumbosacral interbody fusion (AxiaLIF) was designed. Using the image dataset of an adult volunteer, two groups of finite element (FE) models of the AxiaLIF, lumbosacral anterior column fixation (ACF) models and middle column fixation (MCF) models with different bone graft fusion degrees, were prospectively established, and their biomechanical differences were comparatively predicted. In addition, 3D reconstruction was performed by retrospectively collecting CT data from pelvises in 60 adult cases. Their anatomic parameters relating to two groups of models were digitally measured and statistically compared. Numerical analysis revealed that the load and the maximum stress on the screw as well as the maximum stress difference between the screw and peripheral tissues in the MCF model were reduced compared with the ACF model. These indices of both models all decreased markedly in response to the increase in the disc fusion degree. Statistical analysis revealed that the effective fixed length of the sacrum in the MCF model was increased compared with the ACF model (P < 0.05). The surgical dissection distance of presacral vessels and nerves from the axis to sacrum of the MCF model was reduced compared with the ACF model (P < 0.05). The feasible and optimal axis of biomechanical and anatomic significance of the AxiaLIF is similar to the axis of the MCF model. Disc bone graft fusions plus axial screw fixations of middle column could strengthen the biomechanical stability of the AxiaLIF model. Clin. Anat. 32:337-347, 2019. © 2018 Wiley Periodicals, Inc.

Geometric Model for the Postural Characterization in the Sagital Plane of Lumbar Raquis.

The individual's posture is the physical expression of his body. It is modified throughout life and it is determined by the particular anatomical characteristics that directly affect the biomechanics of the spine. The typing of the spinal curvature is important for the knowledge of body posture. The possibility of having a method for the systematic postural characterization of the spine is an essential objective resource in order to obtain normal or control patterns of the spinal morphology of the population. A widely accepted methodology of morphological characterization of the spine is a necessary requirement for the establishment of preventive criteria for spinal pathologies based on epidemiological population studies. It also represents a necessary requirement for the classification of individuals, based on the biomechanical, orthopaedic or ergonomic criteria necessary for disciplines such as sports, industrial design or sports performance. The present study proposes the development of a morphological postural model of the spine in the lumbar region. The model is based on a system of measurement of objective and comparable parameters by means of X-ray analysis, in order to characterize its morphology in the sagittal plane. The comparison of the results in a population of 47 individuals allowed the possibility to carry out a statistical study on three morphological parameters: sacral angle (α1); reversal angle (α2) and degree of lordosis (DL). The statistical hypothesis that the results behave according to a normal distribution with p < 0.05 is relevant and allows the systematization and postural modelling of the individual.

Correlation of Body Mass Index with Pelvis and Lumbar Spine Alignment in Sagittal Plane in Hemophilia Patients.

Introduction: Concern about weight gain among people has been high due to negative health consequences in addition to the increasing prevalence of the problem. Overweight and obesity also occur in patients with hemophilia. Analysis of literature shows that increased body weight might have a biomechanical effect on the spatial orientation of the pelvis and the lumbar spine. The aim of this study was to determine the correlation between body mass index (BMI) and the parameters characterizing the alignment of the sacrum (SS, sacral slope), the pelvis (PT, pelvic tilt; PI, pelvic incidence) and the angle value of lumbar lordosis (LL, lumbar lordosis) assessed in the sagittal plane among patients with hemophilia. Materials and methods: A total of 49 patients were subjected to the study, 23 of whom met the inclusion criteria. Body weight and height were measured. Measurement of the angle values of indicators characterizing the position of the lumbar-pelvic complex was established based on X-ray imaging analysis. Results: Analysis of the correlation between the BMI and sacral, pelvic, and lumbar indicators evaluated in the sagittal plane in the study group of patients with hemophilia showed a correlation between BMI and SS (r = 0.48). SS values were significantly and positively related to PI (r = 0.6; p = 0.002) and LL (r = 0.46; p = 0.02). The results obtained indicate the BMI relationship with the setting of the sacrum in the sagittal plane (SS). After adjusting for the knee flexion contracture, the correlation on the border of significance (b = 0.73, p = 0.07) between the body mass index and the spatial orientation of the pelvis and the spine was revealed. Conclusion: We hypothesize that increased body weight among people with hemophilia might have an effect on the positioning of the lumbosacral region. Therefore, it is believed that preventing obesity among people with hemophilia can contribute to a smaller number of intra-articular hemorrhages and better orthopedic condition of the limb joints, and thus could avoid changes in the lumbosacral region as well as their consequences.

Lack of Exercise-Induced Hypoalgesia to Repetitive Back Movement in People with Chronic Low Back Pain.

PURPOSE: To investigate whether people with chronic low back pain (LBP) show dysfunctional exercise-induced hypoalgesia (EIH) in response to repeated contractions of their back muscles during a lifting task. METHODS: In this cross-sectional observational study conducted on asymptomatic participants (n = 18) and participants with chronic LBP (n = 21), quantitative sensory testing (QST) was applied extensively over the lumbar region and a remote area before and after a repeated task that involved lifting a 5-kg box for ~7 minutes. QST included pressure pain thresholds (PPTs), thermal detection, pain thresholds, and measures of temporal summation. Topographical maps of the percentage change in PPT detected at 16 locations over the lumbar region were generated to explore regional differences and compared between groups. RESULTS: Mean (standard deviation) PPTs measured from 16 sites over the lower back changed significantly in asymptomatic participants (+29.78 kPa [41.4]) following task completion, indicative of EIH, whereas no significant change was observed for the low back pain (LBP) group (-14.87 kPa [61.2]). No changes were detected at the remote site for either group. No changes were revealed for the thermal tests. Temporal summation data revealed decreasing pain sensitivity as the test progressed, but the test response did not change after the exercise for either group. CONCLUSION(S): Unlike asymptomatic individuals, participants with LBP lacked EIH over the lumbar erector spinae muscles following repeated lifting. Although these results should be considered in relation to the study limitations, particularly the absence of a control group, the findings support impaired EIH in patients with LBP.

[Advances in the study of anatomy and biomechanics of lumbosacral transitional vertebrae].

Lumbosacral transitional vertebrae (LSTV) is a common phenomena of developmental anomaly, which is characterized by anatomic variation and biomechanical changes. LSTV is often accompanied with low back pain, lumbar disc herniation, lumbar spinal stenosis, lumbar spondylolisthesis and other spinal diseases. The diagnosis of LSTV has a great significance for proper treatment process. Early imageological studies have limitations on distinguishing different types of LSTV from the aspect of morphological changes. This review focuses on recent studies of LSTV anatomy and variation, its influence in local biomechanics and spinal alignment, and its relationship with spinal diseases.

Determining the extent of the dural sac for the performance of caudal epidural blocks in newborns.

BACKGROUND: Information regarding the position and relationship of vital structures within the caudal canal is important for anesthesiologists who perform a caudal block. This information can be acquired by anatomical dissection, with ultrasound technology, or radiological studies. AIMS: The aim of this study was to determine the position of the dural sac in neonates by measuring the distance of the termination of the dural sac from the apex of the sacral hiatus in neonatal cadavers. METHODS: After careful dissection, the distance from the apex of the sacral hiatus to the dural sac was measured in a sample of neonatal cadavers. RESULTS: In 39 neonatal cadavers, the mean distance from the apex of the sacral hiatus to the dural sac was 10.45 mm. The range of this distance was between 4.94 and 26.28 mm. The mean distance for females was 9.64 mm (range from 6.66 to 15.09); that for males was 10.90 mm (range between 4.94 and 26.28). Linear regression with the log of this distance as the outcome variable gave an estimated 3.3% increase in the distance for each 1 cm increase in the length of the neonate (95% CI for this proportion was 1.91-4.71). CONCLUSION: Anesthesiologists should be aware of the short distance between the sacral hiatus and the dural sac when performing caudal blocks, the shortest distance was 4.94 mm. Armed with this knowledge, caudal techniques should be modified to improve the safety and reduce the risk of complications, such as dural puncture.

Robot-assisted multi-level anterior lumbar interbody fusion: an anatomical study.

BACKGROUND: Minimally invasive surgical approaches still provide limited exposure. Access to the L2-L5 intervertebral discs during a single procedure is challenging and often requires repositioning of the patient and adopting an alternative approach. OBJECTIVES: Investigate the windows to the L2-L5 intervertebral discs to assess the dimensions of the interbody implants suitable for the procedure and evaluate the feasibility of multi-level lumbar intervertebral disc surgery in robot-assisted surgery (RAS) METHODS: Sixteen fresh-frozen cadaveric specimens underwent a retroperitoneal approach to access the L2-L5 intervertebral discs. The L2-L3 to L4-L5 windows were defined as the distance between the left lateral border of the aorta (or nearest common iliac vessel) and the medial border of the psoas, measured in a static state and after gentle medial retraction of the vascular structures. Two living porcine specimens and one cadaveric specimen underwent da Vinci robot-assisted transperitoneal approach to expose the L2-L3 to L4-L5 intervertebral discs and perform multi-level discectomy and interbody implant placement. RESULTS: The L2-L3 to L4-L5 intervertebral disc windows significantly increased from a static to a retracted state (p < 0.05). The mean L2-L3, L3-L4, and L4-L5 windows measured respectively 20.1, 21.6, and 19.6 mm in the static state, and 27.2, 30.9, and 30.3 mm after gentle vascular retraction. The intervertebral windows from L2-L3 to L4-L5 were successfully exposed through an anterior transperitoneal approach with the da Vinci robot on the cadaveric and living porcine specimens, and interbody implants were inserted. CONCLUSION: RAS appears to be feasible for a mini-invasive multi-level lumbar intervertebral disc surgery. The RAS procedure, longer and more expensive than conventional MIS approaches, should be reserved for elective patients.

The effect of recumbency and hindlimb position on the lumbosacral interlaminar distance in dogs: a cadaveric computed tomography study.

OBJECTIVE: To examine the effect of sternal or lateral recumbency, with or without cranial extension of the hindlimbs, on the distance between the dorsal lumbosacral laminae in dogs. STUDY DESIGN: Blinded, randomized, crossover, experimental study. ANIMALS: A total of 19 canine cadavers. METHODS: Computed tomography of the lumbosacral junction was performed in four positions: sternal and right lateral recumbency, with hindlimbs extended cranially or not. Order of positioning was randomized. The lumbosacral interlaminar (LSI) distance, defined as the distance between the dorsal laminae of the seventh lumbar vertebra (caudal margin) and sacrum (cranial margin), was measured for each position by two independent assessors who were unaware of positioning. Mean distances in each position were compared using a paired t-test, corrected for multiple comparisons. RESULTS: For n = 19 cadavers [6 female; median (range) age 9 (0.3-16) years; weight, 20.4 (1.0-34.0) kg], cranial extension of the hindlimbs increased the LSI distance, compared with control, in both sternal (9.2 ± 2.2 mm versus 3.1 ± 1.3 mm, p < 0.001) and right lateral recumbency (8.2 ± 1.9 mm versus 4.9 ± 1.5 mm, p < 0.001). With the hindlimbs extended cranially, sternal recumbency increased LSI distance when compared with right lateral recumbency (p < 0.001). CONCLUSIONS AND CLINICAL RELEVANCE: Cranial extension of the hindlimbs in both sternal and lateral recumbency increases the LSI distance to an extent that is both statistically significant and of potential clinical relevance. Although ease of epidural access or injection was not assessed, the small (1 mm) difference in LSI distance between cranial hindlimb extension in sternal and right lateral recumbency is unlikely to be of clinical relevance. Conversely, cranial extension of the hindlimbs in either sternal or lateral recumbency would be expected to facilitate epidural injection.

Organization of the fascia and aponeurosis in the lumbar paraspinal compartment.

PURPOSE: The thoracolumbar fascia (TLF) and the erector spinae aponeurosis (ESA) play significant roles in the biomechanics of the spine and could be a source of low back pain. Attachment, collagen fiber direction, size and biomechanical properties of the TLF have been well documented. However, questions remain about the attachment of the TLF and ESA in relation to adjoining tissues in the lumbosacral region. Moreover, quantitative data in relation to the ESA have rarely been examined. The aim of this study was to further investigate the anatomical features of the TLF and ESA and to determine the attachments and sliding areas of the paraspinal compartment through dissection. MATERIALS AND METHODS: In 10 fresh cadavers (6 females, 4 males, mean age: 77 ± 10 years), we determined (1) the gross anatomy of the ESA and the TLF (attachments and sliding areas) and (2) the structure of the ESA and the TLF (thickness, width, orientation of collagen fibers). The pennation angle between the axis of the ES muscle fibers and the axis of the collagen fibers of the ESA were also measured. RESULTS: The TLF is an irregular dense connective tissue with a mean thickness of 0.95 mm. The distance between the spinous processes line and the site where the neurovascular bundles pierced the TLF, depending on the vertebral level, ranged from 29 mm at L1 to 75 mm at L3. The ESA constituted a band of regular longitudinally oriented connective fibers (mean thickness: 1.85 mm). Muscles fibers of the ES were strongly diagonally attached to the ESA (mean pennation angle 8° for the iliocostalis and 14° for the longissimus). To a lesser extent, the superficial multifidi were attached to the ESA at the lumbar level close to the midline and at the sacral level. CONCLUSION: The ESA, at twice the thickness of the pTLF, was the thickest dense connective tissue of the paraspinal compartment. The ESA and the TLF circumscribed subcompartments and sliding areas between the TFL and the lumbar paraspinal muscles, between the ES and the multifidus, and between the longissimus and the iliocostalis.

Radiographic analysis of the lumbar and sacral region angles in young Turkish adults.

OBJECTIVE: To determine the normal angular ranges of the lateral spinal alignments in the lumbar and sacral regions. METHODS: This cross-sectional study was conducted at the Kilis State Hospital, Kahramanmaras Sutcu Imam University, Kahramanmaras, Turkey, from February to August 2017, and comprised patients aged 18-27 years who underwent standardised standing lateral lumbar radiography to eliminate hip and low back disorders. All radiographs were obtained from the hospital database as well as the demographic and contact information of each subject. Patients were invited for an interview and physical examination. Standard standing lateral radiographs of the lumbar spine were obtained from those who had no complaint of back pain and/or lower back problems. Sacro-horizontal angle, lumbosacral joint angle and sacral inclination angle were measured on the radiographic images. SPSS 22 was used to analyse data. RESULTS: Of the 150 subjects evaluated, 80(53.33%) were women and 70(46.77) were men. There was no statistically significant difference between women and men regarding lumbar lordosis angle, sacro-horizontal angle and lumbosacral angle (p>0.05). Sacral inclination angle and lower limb length in men were greater than in women (p<0.05). A positive correlation was observed between the lumbar lordosis angle, sacral inclination angle and sacro-horizontal angle values, while a negative correlation with the lumbosacral angle (p<0.05). There was no relationship observed between age, weight, height and body mass index, and sacral inclination, sacro-horizontal and lumbosacral angle values (p>0.05). Lumbar lordosis angle increased depending on the increase of the body mass index (p<0.05). CONCLUSIONS: Values identified can be considered as reference values for young healthy Turkish adults.

Reliability and Precision of Sonography of the Lumbar Multifidus and Transversus Abdominis During Dynamic Activities.

OBJECTIVES: To determine the intrarater reliability and precision of lumbar multifidus and transversus abdominis thickness measurements using freehand sonography in a range of static and dynamic conditions. METHODS: Fifteen asymptomatic participants performed a range of exercises while sonography was used to measure absolute muscle thickness and changes in muscle thickness from rest. Exercise conditions included the abdominal drawing-in maneuver, active straight leg raise, contralateral arm lift, both unloaded and loaded, treadmill walking, and using the Functional Readaptive Exercise Device. Intraday and interday reliability was assessed by intraclass correlation coefficients, and the standard error of measurement was used to assess measurement precision. RESULTS: Good to excellent reliability was achieved for absolute transversus abdominis and lumbar multifidus thickness in all conditions. Measurement precision for absolute lumbar multifidus thickness was ≤2.8 mm for the unloaded contralateral arm lift, ≤1.8 mm for the loaded contralateral arm lift, ≤3.1 mm for treadmill walking, and ≤3.8 mm for the Functional Readaptive Exercise Device; for absolute transversus abdominis thickness, precision was ≤0.6 mm for the abdominal drawing-in maneuver, ≤0.5 mm for the active straight leg raise, ≤0.7 mm for treadmill walking, and ≤0.5 mm for the Functional Readaptive Exercise Device. Good to excellent reliability was achieved for relative transversus abdominis and lumbar multifidus thickness in all conditions. Measurement precision for relative lumbar multifidus thickness was ≤3.7% for the unloaded contralateral arm lift, ≤3.8% for the loaded contralateral arm lift, ≤6.3% for treadmill walking, and ≤7.6% for the Functional Readaptive Exercise Device; for relative transversus abdominis thickness, precision was ≤13.6% for the abdominal drawing-in maneuver, ≤6.9% for the active straight leg raise, ≤11.1% for treadmill walking, and ≤7.2% for the Functional Readaptive Exercise Device. CONCLUSIONS: Acceptable reliability and precision of measurement is achieved for absolute and relative measures of deep spinal muscle thickness using freehand sonography in relatively static and dynamic exercises.

Sonographic spinal imaging of normal anatomy, pathology and magnetic growing rods in children.

The wide availability of ultrasound, along with its lack of ionizing radiation burden and need for sedation for most exams, often make sonography the first line in the imaging evaluation of children. The developing osseous anatomy of the spine in young infants provides a distinct window allowing for a detailed depiction of the spinal canal and its contents, which is not present in older children or adults. Here we review the clinical indications, sonographic technique, normal anatomy and pathology for imaging the lumbosacral spine in neonates and young infants. Additionally, we review the procedure for ultrasound assessment of the lengthening of magnetically controlled growing spinal rods, which allows orthopedists and radiologists to evaluate the effectiveness of distraction procedures of this hardware without the use of ionizing radiation.

Feasibility assessment of shear wave elastography to lumbar back muscles: A Radioanatomic Study.

Low back pain is often associated with tensional changes in the paraspinal muscles detected by palpatory procedures. Shear wave elastography (SWE), recently introduced, allows the stiffness of muscles to be assessed noninvasively. The aim of this work was to study the feasibility of using SWE on the three main lumbar back muscles (multifidus, longissimus, and iliocostalis) in vivo after analyzing their muscular architecture ex vivo. We determined the orientation of fibers in the multifidus, longissimus, and iliocotalis muscles in seven fresh cadavers using gross anatomy and B-Mode ultrasound imaging. We then quantified the stiffness of these three muscles at the L3 level ex vivo and in 16 healthy young adults. Little pennation was observed in the longissimus and iliocostalis, in which the direction of fibers was almost parallel to the line of spinous processes. The multifidus appeared as a multiceps and multipennate muscle. Given the random layering of millimetric fascicles, tendons, and fatty spaces, the multifidus had multiple fiber orientations. Muscular fascicles and fibers were oriented from 9° to 22° to the line of spinous processes. The shear moduli related to stiffness were 6.9 ± 2.7 kPa for the longissimus, 4.9 ± 1.4 kPa for the iliocostalis, and 5.4 ± 1.6 kPa for the multifidus. SWE is a feasible method for quantifying the stiffness of the lumbar back muscles. Clin. Anat. 30:774-780, 2017. © 2017Wiley Periodicals, Inc.

TRANSRECTAL ULTRASONOGRAPHY OF EQUINE LUMBOSACRAL NERVES: PILOT STUDY IN 28 HEALTHY WARMBLOOD HORSES.

A noninvasive method for visualizing lumbosacral nerves would be helpful for horses with suspected lumbosacral plexopathy or injury. The aim of this prospective descriptive pilot study was to characterize the ultrasonographic appearance of the lumbosacral nerves in a sample of healthy horses, and expand on the technique for image acquisition. Horses were recruited for inclusion if they were determined to be healthy and sound based on clinical and lameness evaluation. Transrectal ultrasound images of the lumbosacral nerves (L6, S1, and S2) were obtained for both sides. Landmarks for localization, and techniques for nerve identification and measurement were described. Effects of sex, age, side, and nerve on measured thickness were statistically tested. Twenty-eight warmblood horses were sampled (15 males and 13 females). Ages ranged from 5 to 15 years. Ventral nerve roots from L6 to S2 appeared as tubular structures with a characteristic hyperechoic linear echo pattern. There was no significant difference in nerve vertical diameter between left and right sides. A three-way interaction was found among sex, age and lumbosacral nerve. The L6 nerve in males was significantly larger than S1 only in the youngest group. The S2 nerve was significantly smaller than L6 or S1 regardless of age group or sex. In conclusion, transrectal ultrasound was a feasible method for visualizing and measuring equine lumbosacral nerves. Wide ranges of sizes for each nerve were found between horses, however nerves were bilaterally symmetrical within horses. Side comparison is therefore recommended when nerve pathology is suspected.