Posterior Spines Research Articles

The effects of speed, duration and gender on the relative three-dimensional angular kinematics of the lumbar spine and pelvis during running

INTRODUCTION and AIM Knowledge of lumbo-pelvic motion during running could help in the treatment and prevention of injury to the lumbar spine. Three dimensional angular kinematic patterns of lumbo-pelvic motion at speeds greater than 4m/s have received little attention. Research into the effect of running duration on these patterns is also scarce, and gender has not been taken into account over a wide range of speeds or in relation to time. Therefore the aim was to determine how the lumbar spinal range of motion and the three dimensional angular kinematic patterns that occur during walking and running, differ with running speed and duration, whilst taking gender into account. PATIENTS/MATERIALS and METHODS Three-dimensional angular kinematics of the lumbar spine in relation to the pelvis were recorded in nine male and nine female recreational athletes within the age bracket of 18-35 years. Markers were attached in accordance with [1]. Gait cycle parameters were calculated using markers placed on the lateral malleolus and the distal end of the second metatarsal of both ankles/toes with an additional marker on each heel. Pelvic markers were attached to both anterior superior iliac spines (ASIS) and both posterior superior iliac spines (PSIS). A rigid cluster of three markers was centred over the 12th thoracic spinous process (T12) to determine spinal orientation. A VICON 612 motion analysis system recorded marker coordinate data at 100Hz for treadmill walking speeds of 0.89 and 1.79m/s, and running speeds of 1.79, 2.68, 3.58 and 4.47m/s with no incline. Each recording epoch was 10 seconds. To assess the effect of running duration 10 seconds of data was collected every 5 minutes for 30 minutes at a velocity of 2.68m/s. Range of motion (peak to peak) and time histories (time-normalised to the gait cycle) for lumbar flexion, lateral flexion and axial rotation were ascertained and analysed with respect to the experimental factors. RESULTS The effect of speed on range of motion was highly significant for lumbar flexion, lateral flexion and axial rotation, with all angulations increasing with speed (all p<0.001). However, only axial rotation range of motion increased significantly with running duration (p<0.001). A gender difference in the trend for lateral flexion with respect to speed was detected (p<0.05) but no strong interaction with duration was evident. Females displayed higher overall ranges of motion throughout. Whilst kinematic patterns differed in amplitude, little variance in timing across speed, duration or gender was observed, with the exception of lumbar flexion between genders. DISCUSSION and CONCLUSIONS As expected [2], spinal motion increased with speed. Whilst this motion is not enough, per se, to induce acute spinal injury, a temporal co-ordination of peak angulation with peak loading may be chronically deleterious to intervertebral disc biomechanics. As tiredness sets in, this study suggests that the body compensates by increasing axial rotation of the spine, probably in an attempt to utilise upper body angular momentum to augment lower body propulsive ground reaction forces and/or swing phase kinematics. This study has also evidenced a gender difference in spinal motion, as found before [3] which may be attributed to height and limb length differences. Nonetheless, differences in lumbo-pelvic motion observed between genders are consistent enough to merit careful consideration of subjects in related future investigations, especially with regard to speed. Complementary studies are suggested to investigate the relative angular kinematics of the lumbar spine and pelvis at running speeds faster than 4.5m/s; for durations longer than 30 minutes; and in LBP populations. REFERENCES [1] Schache, A. G., Blanch, P., Rath, D., Wrigley, T., & Bennell, K. (2002). Three-dimensional angular kinematics of the lumbar spine and pelvis during running. Human Movement Science, 21, 273-293. [2] Saunders, S. W., Schache, A., Rath, D., & Hodges, P. W. (2005). Changes in the three dimensional lumbo-pelvic kinematics and trunk muscle activity with speed and mode of locomotion. Journal of Clinical Biomechanics, 20, 784-793. [3] Schache, A. G., Blanch, P., Rath, D., Wrigley, T., & Bennell, K. (2003). Differences between the sexes in the three-dimensional angular rotations of the lumbo-pelvic-hip complex during treadmill running. Journal of Sports Sciences, 21, 105-118.

Effect of bone-borne rapid maxillary expanders with and without surgical assistance on the craniofacial structures using finite element analysis

The aim of this study was to analyze stress distribution and displacement of the craniofacial structures resulting from bone-borne rapid maxillary expanders with and without surgical assistance using finite element analysis. Five designs of rapid maxillary expanders were made: a tooth-borne hyrax expander (type A); a bone-borne expander (type B); and 3 bone-borne surgically assisted modalities: separation of the midpalatal suture (type C), added separation of the pterygomaxillary sutures (type D), and added LeFort I corticotomy (type E). The geometric nonlinear theory was applied to evaluate the Von Mises stress distribution and displacement. The surgical types C, D, and E demonstrated more transverse movement than did the nonsurgical types A and B. The amounts of expansion were greater in the posterior teeth in types A and B, but in types C, D, and E, the amounts of expansion were greater in the anterior teeth. At the midpalatal suture, the nonsurgical types showed more anterior expansion than did the posterior region, and higher stresses than with the surgical types. Type B showed the highest stresses at the infraorbital margin, anterior and posterior nasal spines, maxillary tuberosity, and pterygoid plate and hamulus. The 3 surgical models showed similar amounts of stress and displacement along the teeth, midpalatal sutures, and craniofacial sutures. Therefore, when using a bone-borne rapid maxillary expander in an adult, it is recommended to assist it with midpalatal suture separation, which requires minimal surgical intervention.

PELVIC TILT: RELIABILITY OF MEASURING THE STANDING POSITION AND RANGE OF MOTION IN ADOLESCENT ATHLETES

BackgroundStanding pelvic posture remains a common assessment in sports therapy. The palpation technique assessing the relative position of the anterior and posterior superior iliac spines is widely used to quantify...

A New Titanosaur (Dinosauria, Sauropoda) from the Upper Cretaceous (Cerro Lisandro Formation) of Mendoza Province, Argentina

Abstract. Quetecsaurus rusconii gen. et sp. nov. is a new titanosaur (Dinosauria, Sauropoda) from the Neuquen Basin of Mendoza Province, Argentina. The specimen comes from red mudstones of the Cerro Lisandro Formation (middle-late Turonian, Upper Cretaceous), and is the first sauropod with well-preserved remains to be discovered in this formation. The holotype includes a postorbital, teeth, the atlas, a posterior cervical vertebra, an incomplete dorsal vertebra, a posterior caudal centrum, dorsal ribs, a coracoid, fragments of a humerus, radius and ulna, and five metacarpals. It is characterized by the following combination of autapomorphies: (1) intercentrum of atlas with a prominent anteroventral border and expanded posteroventral processes; (2) posterior cervical neural spines with incipient lateral expansions; and (3) humerus with strongly sigmoid proximal border, rounded proximomedial border, and angular proximolateral corner. A preliminary cladistic analysis placed Quetecsaurus as a sister taxon of ...

Assessment of inter- and intra-operator cephalometric tracings on cone beam CT radiographs: comparison of the precision of the cone beam CT versus the latero-lateral radiograph tracing

BackgroundIn this study we aimed at quantifying the possible errors which may occur when assessing specific reference planes and linear derivants on cephalometric radiographs traced manually and digitally. Furthermore, we have compared the precision of the tracings according to both the two- and three-dimensional (2D and 3D respectively) techniques and between clinicians.FindingsWe have obtained via cone beam computed tomography (CBCT) archive of the orthodontics department of the University of Milan 20 cone beam CT radiographs from which we have obtained 20 latero-lateral radiographs. Five independent clinicians referred to as A, B, C, D, E have been randomly selected to trace both radiographs maintaining the same working and lighting conditions to minimize the possibility of operator- and environment-dependent errors from occurring. The results have been statistically assessed by Student’s t test. The comparison of the data gathered from the tracings in 2D and 3D shows that certain measurements have statistically significant differences. Particularly, the difference in the measurements of the sagittal dimension of the mandible and the anterior and posterior nasal spines has resulted to be statistically significant. The results of the intra-operator comparison proved that the 3D technique is extremely precise.ConclusionOur study determines that the 3D technique allows to obtain more precise results and with several advantages when compared to the conventional technique such as a true representation of the anatomical structures, less risk of errors occurring due to clinician skills and absence of overlapping anatomical structures.

Spine curvature analysis between participants with obesity and normal weight participants: a biplanar electromagnetic device measurement.

To analyse and compare standing thoracolumbar curves in normal weight participants and participants with obesity, using an electromagnetic device, and to analyse the measurement reliability. Material and Methods. Cross-sectional study was carried out. 36 individuals were divided into two groups (normal-weight and participants with obesity) according to their waist circumference. The reference points (T1–T8–L1–L5 and both posterior superior iliac spines) were used to perform a description of thoracolumbar curvature in the sagittal and coronal planes. A transformation from the global coordinate system was performed and thoracolumbar curves were adjusted by fifth-order polynomial equations. The tangents of the first and fifth lumbar vertebrae and the first thoracic vertebra were determined from their derivatives. The reliability of the measurement was assessed according to the internal consistency of the measure and the thoracolumbar curvature angles were compared between groups. Results. Cronbach's alpha values ranged between 0.824 (95% CI: 0.776–0.847) and 0.918 (95% CI: 0.903–0.949). In the coronal plane, no significant differences were found between groups; however, in sagittal plane, significant differences were observed for thoracic kyphosis. Conclusion. There were significant differences in thoracic kyphosis in the sagittal plane between two groups of young adults grouped according to their waist circumference.

Acanthocephalans from fishes and amphibians in Vietnam, with descriptions of five new species

Eight species of acanthocephalans are reported, and five are new. Specimens of Neoechinorhynchus (Hebesoma) manubrianus Amin, Ha & Ha, 2011 were similar to the original description. Neoechinorhynchus (Hebesoma) spiramuscularis n. sp. (Neoechinorhynchidae), from Xenocypris davidi, has a unique proboscis receptacle wrapped in a spiral muscular layer, and an undulating flask-shaped lemnisci, as well as double para-receptacle structures. Heterosentis mongcai n. sp. (Arhythmacanthidae), from Acreichthys sp., has a small fusiform trunk with an unarmed cone and anterior trunk spines, and a proboscis with two circles of rooted apical hooks and 3–4 circles of rooted posterior spines as well as a para-receptacle-like structure at the posterior end. The poorly known Filisoma indicum Van Cleave, 1928 is fully described and illustrated for the first time. Acanthocephalus parallelcementglandatus n. sp. (Echinorhynchidae), from Clarias batrachus, is distinguished from other species of Acanthocephalus by its small fusiform trunk and parallel tubular cement glands. Pseudoacanthocephalus coniformis n. sp. (Echinorhynchidae), from Hylarana sp., is distinguished from other species by having an anterior trunk collar and staggered prominent filiform cement glands, among other features. Cathayacanthus spinitruncatus n. sp. (Rhadinorhynchidae), from Leiognathus equulus, is distinguished from the only two known species of the genus by having a very long and slender proboscis with more than 50 hooks per row and a totally spined trunk. The generic diagnosis of Cathayacanthus Golvan, 1969 is emended. Rhadinorhynchus johnstoni Golvan, 1969 (Rhadinorhynchidae) perfectly fits the only complete description of that species from the Fiji Islands.

Where is the apex of the sacral hiatus for caudal epidural block in the pediatric population? A radio-anatomic study

Caudal epidural block (CEB), administered through the sacral hiatus, is a regional anesthetic technique commonly used in children. To facilitate and optimize pediatric CEB, morphometric data that may be important for the sacral hiatus have been obtained using multidetector computed tomography (MDCT). This study is the first radio-anatomic study designed to address this topic in children. Images of 79 children (39 girls and 40 boys between 1 and 9 years old) were divided into three groups according to age [group I (ages 1-3), group II (ages 4-6), and group III (ages 7-9)] and were retrospectively examined. Data were gathered via 3D volume-rendered images. Measurements included the height and width of the sacral hiatus, S2-S4 (sacral vertebra) distance, the distances between the poles of the unfused spinous process of each sacral vertebra, and the dimensions of an imaginary triangle formed between the right and left posterior superior iliac spines (PSIS) and the apex of the sacral hiatus. The most frequently fused spinous process was at S2 level. The mean S2-S4 distance was 1.36 cm for group I, 1.78 cm for group II, and 2.17 cm for group III. There was not the imaginary equilateral triangle used in the method of finding the sacral hiatus for CEB, and the apex of this triangle did not occur at the standard level (S4) in most of the children. It was observed that the apex deriving from the most distal fused spinous process was at the level of S2 in one of two children. Dural puncture is inevitable for CEB applied at the S2 level. Consequently, CEB should be applied below this level (range, 1.36-2.17 cm) from the midpoint of the interspinous distance between the PSIS (at the same level with S2) in children aged 1-9 years.

Intra- and inter-rater reliability of a modified measure of hand behind back range of motion

The aim of this reliability study was to identify the clinimetric properties, specifically intra- and inter-rater reliability, for measuring the functionally and clinically important hand behind back (combined shoulder internal rotation/adduction and elbow flexion) range of motion using a modified technique. Sixty asymptomatic participants (20 male, 40 female) aged 45.4 ± 11.7 years (mean ± SD). Hand behind back was measured as the distance from the mid-line between the posterior superior iliac spines (PSIS) to the tip of the thumb and recorded in centimetres above the PSIS (a positive measure) or below the PSIS (a negative measure). The intra- and inter-rater reliability for the measurement were excellent, with ICC (2,1) of 0.95 for intra-rater and ICC (2,2) of 0.96 for inter-rater reliability. The standard error of the measurement (SEM) and smallest real difference (SRD) values showed acceptable levels of measurement error, SEM 4.3 mm and SRD 12.8 mm for intra-rater reliability and SEM 2.6 mm and SRD 7.7 mm for inter-rater reliability. The assessment of hand-behind-back motion from a point equidistant between the PSISs to the tip of the thumb is more reliable than traditional methods and a useful clinical tool.

Larval and juvenile development of dusky grouper Epinephelus marginatus reared in mesocosms

The larval development of the dusky grouper Epinephelus marginatus up to the benthic juvenile stage is described in detail to establish a reference for their larval identification. Development is described in terms of ontogenetic changes in morphology, growth, pigmentation, fin structure and skeletal structure. Larvae were reared in mesocosms at a mean temperature of 24·3° C, salinity of 36·5, dissolved oxygen of 6·4 mg l(-1) and pH of 8·2. Newly hatched larvae had an estimated total length (LT ) of 2·3 mm. On the second day post hatching the yolk was almost fully absorbed with traces of the oil globule still present, the eyes were already pigmented and mouth and gut functional. At this stage the cranial skeletal elements for feeding and breathing (mouth and gills) and the pectoral-fin support were already present. About 50% of the observed larvae had food in their guts. Pigmentation was very characteristic, consisting of two large chromatophores visible on the edge of the primordial fin, close to the midpoint of the post-anal region of the body and over the midgut and hindgut and post-anal portion of the body. At 2·9 mm LT the emergence of the second dorsal-fin spine, characteristic of the Epinephilinae, was clearly visible. The pre-flexion stage started in larva of 3·2 mm LT . At 5·5 mm LT the larvae possessed posterior preopercular angle spines, and the dorsal and pelvic spines presented serrated edges and were pigmented. The water surface-tension-related death of the yolk sac and pre-flexion larvae described in the rearing of several other grouper species did not occur during E. marginatus culture. Notochord flexion, with initial ossification of the caudal-fin supporting elements, started at 6·6 mm LT . At this stage the major melanophores, preopercular, dorsal and pelvic spines and mandibular teeth were already present. Transformation of larvae into juveniles occurred when larvae averaged 13·8 mm LT . Juveniles with a mean LT of 20·1 mm started to settle and most of them were benthic with a mean LT of 26·8 mm.

Revision of the Indo-West Pacific genus Brachypterois (Scorpaenidae: Pteroinae), with description of a new species from northeastern Australia.

A taxonomic revision of the scorpaenid genus Brachypterois resulted in three valid species. Brachypterois serrulifer Fowler 1938, previously regarded as ajunior synonym of Sebastes serrulatus Richardson 1846, can be distinguished from its congeners by having usually 16 pectoral-fin rays (vs. 15 in the congeners) and 0-22 spines on the median lateral ridge of the maxilla (vs. almost always absent), in addition to longer dorsal- and anal-fin soft rays, relatively fewer large dark spots on the caudal fin, and the posterior lacrimal spines usually directed ventrally. Brachypterois curvispina sp. nov., described on the basis of 32 specimens, can be distinguished from B. serrulata (Richardson 1846) by having fewer number of scale rows in the longitudinal series 41-45 (vs. 44-51 in B. serrulata); relatively long head, its length 41.6-44.5 (mean 43.1)% SL [vs. 38.3-43.1 (mean 40.2)% SL]; posterior lacrimal spines usually directed posteriorly, with the tip curved strongly upward in large males (vs. simply directed posteroventrally); and posteriorly directed spine(s) on the posterior corner of the outer angular ridge (vs. directed ventrally). Brachypterois serrulifer is distributed widely in the Indo-West Pacific, whereas distributional ranges of B. curvispina sp. nov. and B. serrulata are restricted to northeastern Australia and the northwestern Pacific, respectively. Intraspecific variation, including sexual dimorphism and ontogenetic changes in the three species are described in detail. A neotype, collected from southern Taiwan, is designated for S. serrulatus Richardson 1846.

Acanthorhachis, a new genus of shark from the Carboniferous (Westphalian) of Yorkshire, England

AbstractAn association of diverse hollow spines and dermal denticles (ichthyoliths) from the Carboniferous (Westphalian) of Todmorden, Yorkshire, England are attributed to a new genus of enigmatic shark that may lie close toListracanthusNewberry &amp; Worthen, 1870. Scanning electron microscopy shows that denticle morphology is highly variable, but forms a morphocline including elongate multi-spined elements as well as robust dome-like stellate denticles and recurved spinose elements. Histological analysis suggests an absence of enameloid. Continuous variation of form between elongate multi-cusped spines to boss-like circular denticles shows that all previously described Palaeozoic species ofListracanthusare probably junior synonyms of the type speciesL.hystrixNewberry &amp; Worthen, 1870. The status ofListracanthusas a surviving ‘Lilliputian’ taxon after the Permian extinction is questioned. Although the new specimen has affinities withListracanthus, significant differences in the form of the posterior spines on elongate denticles warrants its placement in the new genusAcanthorhachisgen. nov. The family Listracanthidae is erected to accommodateListracanthusandAcanthorhachis.

An alternative technical marker set for the pelvis is more repeatable than the standard pelvic marker set

Multiple marker sets and models are currently available for assessing pelvic kinematics in gait. Despite the presence of a variety models, there are still debates on their reliability and consistency, and consequently there is no clearly defined standard. Two marker sets were evaluated in this study: the ‘Traditional’ where markers are placed at the anterior and posterior superior iliac spines (ASISs, PSISs); and the ‘Cluster’, where a cluster of three orthogonal markers fixed on a rigid based is attached to the sacrum. The two sets were compared with respect to intra and inter session standard deviations of maximum pelvic tilt, obliquity and rotation angles. The repeatability between and within sessions was measured using coefficient of multiple correlation (CMC). Also the similarity between the two sets was assessed using inter-protocol CMC (ipCMC). Both data sets generated showed high within and between session repeatability in the sagittal plane (CMC>0.80), although the Cluster method showed higher repeatability than that of the Traditional method in non-sagittal plane motion for both within and between sessions. The authors are not aware of other studies reporting the differences in intra and inter session variability and repeatability values for different body mass index categories such as overweight and obese subjects with relatively large sample size. Hence the Cluster method overcomes a number of theoretical and experimental limitations such as minimising the marker occlusion and is a reliable alternative to the Traditional (the standard) marker set.

Pelvic girdle enthesitis in spondyloarthritis

A 21-year-old woman was admitted to our hospital for a longstanding history of inflammatory type low back pain. There was no significant medical history. Physical examination revealed pressure pain of superior posterior iliac spines.

The morphology and SSU rRNA gene sequence analysis of a poorly-known brackish water ciliate, Pinacocoleps tesselatus (Kahl, 1930) (Ciliophora, Colepidae) from Hangzhou Bay, China.

The morphology and infraciliature of a poorly-known colepid ciliate, Pinacocoleps tesselatus (Kahl, 1930) Foissner et al., 2008, collected from brackish-water biotope (salinity 12 per thousand) in Hangzhou Bay, China, were investigated using live observations and silver impregnations. This species is characterized by its length of 60-85 μm in vivo, ovular shape, two anterior and three posterior spines, 21-25 longitudinal and 11 transverse ciliary rows on average, a macro and micro nucleus, and one terminal contractile vacuole. The key to all known seven Pinacocoleps species is updated. Additionally, we characterized the taxon P. tesselatus via small subunit rRNA gene data. Our phylogenetic analyses performed using both maximum-likelihood and Bayesian methods indicate that P. tesselatus falls into the core assemblage of the family Colepidae.

Validity of palpation techniques for the identification of the spinous process L5

For spinal diagnosis and treatment it is important to be able to identify spinal levels by palpation. The objective of this diagnostic study was to examine the validity of four palpation techniques to detect the fifth lumbar vertebra (L5). A physiotherapist examined 66 low back pain patients using first three techniques. Motion palpation (MP), palpation via the posterior superior iliac spines (PSIS technique) and palpation via the iliac crests (CI technique) were deployed in random order. The spinous processes identified using these techniques were marked using an UV marker. The fourth technique was the motion palpation using the previously visible marked landmarks PSIS and CI (MP+). X-rays were taken as a reference standard through replacing the markings by radio-opaque markers. The accuracy of the single techniques ranged from 45% to 61%. There was no significant difference between the individual techniques. If two techniques were in agreement the accuracy ranged from 58% to 78%. If three techniques were in agreement the accuracy ranged from 69% to 83%. This was a significant to highly significant improvement compared to single techniques. If there is agreement between palpation techniques, the accuracy can be significantly improved. This illustrates the need to combine techniques and to relate them to each other. Future studies should investigate combined techniques using marker for further anatomical structures.

The assessment of the body posture and motor abilities of 14-year-old boys and girls

AbstractAim of the study: The purpose of this study was to assess the body posture parameters measured with the photogrammetric Moiré’s method, and motor abilities of 14-year-old boys and girls living in Kraków.Material and methods: The study group consisted of 273 children, including 140 girls and 133 boys, aged 14. Their height and body mass were measured. Their body posture was assessed using the Moiré’s method, as a result of which 14 parameters were described (6 parameters in plane median, 1 in plane transverse and 7 in plane coronal). Motor abilities were assessed using the test of marching balance as well as some trials being part of the battery test EUROFIT.Results: As far as the body posture, significant differences between the boys and the girls were observed in respect of five parameters assessed with the Moiré’s method thoracic kyphosis angle, elevation of the left inferior angle of scapulae, lowering of the left waist triangle, the difference in height of posterior superior iliac spines, the maximum leftwards deviation of the spine line from the line C7-S1. The statistically significant differences between the boys and the girls were pointed out in terms of the motor abilities with the components of strength, as well as suppleness and flexibility.Conclusions: Worse body posture of girls and boys aged 14 does not lead to a decrease in physical fitness, therefore it seems that it is necessary to increase the time of physical exercises for these children compared to their peers with better posture.

A NEW TITANOSAUR (DINOSAURIA, SAUROPODA) FROM THE UPPER CRETACEOUS (CERRO LISANDRO FORMATION) OF MENDOZA PROVINCE, ARGENTINA

Quetecsaurus rusconii gen. et sp. nov. is a new titanosaur (Dinosauria, Sauropoda) from the Neuquén Basin of Mendoza Province, Argentina. The specimen comes from red mudstones of the Cerro Lisandro Formation (middle-late Turonian, Upper Cretaceous), and is the first sauropod with well-preserved remains to be discovered in this formation. The holotype includes a postorbital, teeth, the atlas, a poste- rior cervical vertebra, an incomplete dorsal vertebra, a posterior caudal centrum, dorsal ribs, a coracoid, fragments of a humerus, radius and ulna, and five metacarpals. It is characterized by the following combination of autapomorphies: (1) intercentrum of atlas with a prominent anteroventral border and expanded posteroventral processes; (2) posterior cervical neural spines with incipient lateral expansions; and (3) humerus with strongly sigmoid proximal border, rounded proximomedial border, and angular proximolateral corner. A preliminary cladis- tic analysis placed Quetecsaurus as a sister taxon of Lognkosauria (Mendozasaurus + Futalognkosaurus). Quetecsaurus shares with the lognkosaurs the presence of cervical neural spines with ‘lateral laminae’, but relatively reduced in comparison with those taxa. This discovery provides new information on the diagnosis of Lognkosauria within South American titanosaurs.

The Myth of the Equiangular Triangle for Identification of Sacral Hiatus in Children Disproved by Ultrasonography

A triangle formed by the sacral hiatus and posterior superior iliac spines (PSISs) has been known as equiangular and has been proposed as a way to help identify the sacral hiatus for a caudal block. In children, however, no feasibility study of this triangle has been performed. We compared the expected sacral hiatus obtained from the equiangular triangle method and the real sacral hiatus confirmed by ultrasound. Eighty children (aged 0.5-72 months) were placed in the left lateral decubitus position in full hip flexion. The vertex of an equiangular triangle formed inferior to PSISs was considered as the expected sacral hiatus by classic bony landmarks. The real sacral hiatus was identified by ultrasound. The angle formed by the 2 lines connecting each PSIS and the real sacral hiatus (angle θ) was also measured. The distances between the midpoint of PSISs and expected sacral hiatus (distance E) and real sacral hiatus (distance R) were measured and compared. The angle θ was greater than 60 degrees in all children (79.3 [9.3] degrees) and negatively correlated with age younger than 1 year. Distance R (3.5 [1.1] cm) was significantly shorter than distance E (4.9 [1.2] cm) (P< 0.001). The distance R positively correlated with age, weight, height, and the distance between the PSISs. In children, using the equiangular triangle to identify the sacral hiatus may be inappropriate because the actual triangle formed by the sacral hiatus and PSISs is not equiangular.

Morphometric Study of Sacral Hiatus with Significance in Interventional Clinical Procedure

Introduction: The sacral hiatus is an important portal for interventional clinical procedure. Identification of sacral hiatus is usually easy but sometime it becomes difficult particularly in obese person. Aim of present study was to identify additional anatomical landmarks to increase the success rate of trans-sacral hiatal procedure. Methodology: The morphometric study was conducted on 31undamaged adult sacra. The measurements were done with the help of Vernier caliper and goniometer. Results : The posterior superior iliac spines impose upon upper part of lateral sacral crest (superolateral crest). The distance between two superolateral crests was considered as the base and distance from two superolateral crests to apex of sacral hiatus as two sides of the triangle. The base, right side and left side of the triangle were 65.81 mm ± 4.00mm, 66.74 mm ± 6.18 mm and 66.84mm ± 6.07m respectively. The mean depth (AP diameter) of sacral canal at the apex of sacral hiatus was 4.17 mm ± 1.18 mm. An additional important landmark, the mean distance from the level of sacral cornua to the level of S2 foramina was 59.23mm ± 4.77mm. Conclusion: The triangle formed by the two superolateral crests and apex of the sacral hiatus was an equilateral triangle in most of the sacra and this is very important parameter in localization of sacral apex in transacral hiatal procedures. The AP diameter of sacral canal at the apex was adequate for passage of needle and endoscope in most of the specimens.