Surface alignment to unmask scoliotic deformity in surface topography

Comparisons of back surface topography to monitor scoliosis are hampered by shape change due to other causes, primarily stance variations. The aim is to extract changes due only to the scoliosis from the observed changes. Surface (back) topography data were derived from 2 patients measured repeatedly (10x) at a single visit and from 45 patients measured at routine clinical visits. The measured back shapes were aligned to obtain the position of closest fit using a mathematical technique. The shape similarities were then quantified with a closeness-of-fit index. The similarity indices from the alignments were used to estimate noise factors due to postural variation, relative to typical patient change. Surface alignment has also been trialled using models with predictable topographic changes to determine whether the noise sources can be modelled. The values of the root-mean-square of the residual surface differences at all measured points after mathematical back shape alignment were used as a surface similarity index. The magnitude of this index for the repeatedly measured back shapes indicates the back shape variation due to stance, and has been compared with the variation found in normal patients. The similarity index has also been examined for cases both with and without modelled changes to estimate the effectiveness of stance modelling. The noise due to stance change was indicated by a surface similarity index which averaged 2.0 mm; the index for backs measured at routine visits averaged 3.5 mm. It was concluded that noise due to stance is significant and deserves to be recognised, in the comparison of back surfaces in three-dimensions. There is evidence that changes due to noise can be modelled.

Iliocostalis muscles in three mammals (dolphin, goat and human): Their identification, structure and innervation

Iliocostalis (IC) muscles were studied in four dolphin embryos, three goat embryos and four Japanese adult cadavers through macroscopic dissection. The IC muscles of the dolphin were located on the lateral aspect of the trunk and displayed an intercostal arrangement. In contrast, the IC muscles in both the goat and human showed a double-layered architecture formed by a multisegmental muscle-tendon complex and were located on the lateral and medial sides of the costal angle, respectively. Generally, the nerve to the iliocostalis (NIC) in the dolphin and goat did not form a common trunk with the nerve to the longissimus on the epaxial plane, whereas in humans the NIC ran parallel to the nerve to the longissimus part of the way. The individual NIC ran caudolaterally, innervating the one lower (caudal) metameric division of the IC muscle in the dolphin and piercing the fascia of the IC muscles at a point in the next caudal intercostal level in the goat and human. In the upper thoracic part of the goat and human, the caudal shift of innervation was obscured, where the IC muscles were close to the vertebrae. The course of the NIC was closely related to that of the lateral cutaneous branch. The present study shows that the NIC is commonly destined for the one lower intercostal level among the three mammalian species, with their respective IC muscles having distinctly different structural complexity.

[<< Reverse >> latissimus dorsi musculocutaneous flap: anatomic study of the secondary pedicles]

PURPOSE

The latissimus dorsi flap based on the secondary segmental vessels, wich is termed << reverse >> or << distally based >> latissimus dorsi flap, has been used to repair major thoraco-lumbar defects, to close myelomeningoceles and to reconstruct congenital diaphragmatic absences. The arc of flap rotation is markedly restricted because the blood supply is segmental. It is the most important factor that limits the flap mobility and so restricts its use. The authors report an anatomic study of these secondary pedicles in order to improve the flap dissection and to extend the arc of flap rotation.

MATERIAL AND METHOD

The precise location of the secondary pedicles of the flap was determined by 24 anatomic dissections.

RESULTS

The latissimus dorsi has 3, 4 or 5 secondary pedicles respectively in 50%, 25% and 25% of cases in the study. These pedicles take origin from the dorsal branches of the posterior intercostal arteries of the 7th, 8th, 9th, 10th and 11th intercostal spaces.

CONCLUSION

The number of secondary pedicles is not constant. The entire flap can be safely based on 2 secondary pedicles when the latissimus dorsi muscle has 3 secondary pedicles. When this muscle has 4 or 5 secondary pedicles, the entire flap should be at least based on 3 secondary pedicles, particularly if the skin island is very far from the origin of these vessels.

Site-specific protective effect of broad-spectrum sunscreen on nevus development among white schoolchildren in a randomized trial

BACKGROUND

Melanocytic nevus density is a strong risk factor for cutaneous malignant melanoma. Reducing the number of nevi in children may reduce the risk of their developing melanoma as adults.

OBJECTIVE

We sought to assess the effect of sunscreen use on nevus development by anatomic sites and by nevi of different sizes for white schoolchildren in a randomized trial.

METHODS

We compared the new nevus count between the sunscreen intervention group (n = 145) and the control group (n = 164) by anatomic site.

RESULTS

Children randomized to the sunscreen group had significantly fewer new nevi on the trunk than children in the control group. The differences were more pronounced among the freckled children than children with no freckles.

LIMITATIONS

Potential limitations to this study include relatively small numbers of enrolled children, and a follow-up period of only 3 years.

CONCLUSION

Sunscreen use attenuated new nevus development on intermittently sun-exposed body sites for white schoolchildren, particularly among the freckled children.

In vivo measurement of lower back deformations with Fourier-transform profilometry

Through the variation of their cross sections, the in vivo response of lower back muscles to low loading in an upright seated posture is explored by the Fourier-transform profilometry technique. The maximization of its sensitivity allows us to reach an adequate resolution for the evaluation of low-back displacements. Refinements of the fringe pattern analysis permit the minimization of errors. The experiments show an asymmetric distribution of the displacement during head rotation movements. Significant contribution of the lower back to grasping exertions is also observed. These results are thought to be useful for early defect detection in the lower back.

Elevator muscle of the tendon of latissimus dorsi muscle

Muscular dispositions in the axilla acquire importance under certain surgical procedures that involve the axillary artery ligature. These supernumerary muscles make the approach to the axillary fossa and their content difficult. We dissected 108 formalized corpses from adult male individuals. The specimens belong to the topographic Anatomy Unit of the Faculty of Medicine, Universidad de La Frontera, Chile. In all dissections, a rare and infrequent muscular variation attributed to the presence of a elevator muscle at the dorsal part of the latissimus muscle on the right upper limb from an adult individual was found. This muscle was fusiform and originated at the coracoid process by a short tendon of cylindrical form inserted in the dorsal superior part of the tendon of the latissimus dorsi muscle. Muscular belly and tendons of origin and insertion were closely related to the brachial plexus and the axillar vessels that they crossed.

Lymphatic drainage of the skin

A successful sentinel lymph node biopsy (SLNB) in melanoma patients requires an accurate map of the pattern of lymphatic drainage from the primary site. Lymphoscintigraphy (LS) can provide such a map. LS needs an understanding of lymphatic physiology, an appropriate small-particle radiocolloid, high-resolution collimators, and imaging protocols that detect all sentinel nodes (SNs). Patterns of lymphatic drainage from the skin are not clinically predictable. Unexpected drainage has been found from the skin of the back to SNs in the triangular intermuscular space (TIS) and the paraaortic, paravertebral, and retroperitoneal areas. It can also occur from the base of the neck up to nodes in the occipital or upper cervical areas or from the scalp down to nodes at the neck base, bypassing many node groups. Upper limb drainage can be to SNs above the axilla. Interval nodes not uncommonly can be SNs, especially on the trunk. Lymphatic drainage may involve SNs in multiple nodal fields, and drainage across the midline of the body is quite common. Because micrometastatic disease can be present in any SN regardless of its location, all true SNs must be biopsied. LS is an important first step to ensure this goal is achieved.

[Anatomy of latissimus dorsi and its clinical application]

OBJECTIVE

To investigate the feasibility of segmentation of latissimus dorsi on the basis of anatomy and electrophysiology.

METHODS

Ten cadaveric latissimus dorsi was dissected according to the blood supply, nerve innervation. Electromyelogram (EMG) of latissimus dorsi of 13 healthy persons was recorded with superficial electrode plate in the motion of shoulder joint. The results of record were managed with statistic methods. Ten patients(including reconstruction of breast and repair of scar on elbow joint and on chest wall) were treated with the lateral inferior myocutaneous island flap.

RESULTS

According to the medial and lateral vasculonervous branches, latissimus dorsi can be divided into the medial superior and lateral inferior segments. The clinical application of the segment achieved good results in reconstructing breast and in repairing scars on elbow and on chest wall.

CONCLUSION

Latissimus dorsi can be divided into two segments and applied separately. The lateral inferior segment is more useful in shoulder motion.

Genetic algorithm-neural network estimation of cobb angle from torso asymmetry in scoliosis

Scoliosis severity, measured by the Cobb angle, was estimated by artificial neural network from indices of torso surface asymmetry using a genetic algorithm to select the optimal set of input torso indices. Estimates of the Cobb angle were accurate within 5 degrees in two-thirds, and within 10 degrees in six-sevenths, of a test set of 115 scans of 48 scoliosis patients, showing promise for future longitudinal studies to detect scoliosis progression without use of X-rays.

Effect of conformational aspects on the movement of the equine back

The relationship between structure and function is important in the judgement of the horse. Twenty sound riding horses walked and trotted on a treadmill. The movement of the backs of each of the horses was measured using a commercially available movement analysis system. Morphometric, spatiotemporal and kinematic information were correlated to investigate the effect of conformation on movement. Taller and heavier horses seem to have longer thoracic and lumbar backs, and are wider at the pelvis. Horses with longer strides extended and flexed their backs in the caudal saddle region to a greater extent at the walk, but not the trot. Horses with greater angle of L5 tend to extend and flex this region of the back more. At the walk and trot, a long thoracic back results in greater lumbar lateral bending. A negative relationship was found between the curvature of mid-thoracic back and the amount of lateral bending of L1 and L3 and axial rotation of the pelvis at the trot. There are clear relationships between back conformation and movement that may be important to the orthopaedic health of the horse. Further understanding of the relationships between conformation, movement and injury may provide an objective basis for the evaluation of future performance and soundness.

Lumbar hernia: anatomical route assessed by computed tomography

Lumbar hernia is classically described as arising from the superior (Grynfeltt's) lumbar triangle or the inferior (Jean-Louis Petit's) lumbar triangle. The present anatomical study based on a computed tomography examination performed in a patient with lumbar hernia, has led to the suggestion that lumbar hernias cross the lumbar wall through a musculoaponeurotic tunnel, whose deep and superficial openings are the superior and inferior lumbar triangles, respectively.

User friendly computer profilometry

Portable optical profilometer for measurement and analysis of the human back shape has been developed. The driving user friendly software includes correction of distortion of the observation lens, data calibration, three-dimensional Z-axis rotation of the patient normalizing his position, calculus of the curvature map (second derivative), and precise indication of different characteristic points of the back including the spinous processes line. This instrument enables the examination of the back in both erected and bent positions.

3D back shape in normal young adults

In today's climate of evidence based medicine, there is an increasing emphasis on objective assessment to monitor treatment effectiveness. Although spinal posture and back shape are commonly assessed by clinicians, current practice is based on subjective findings and unreliable objective tools. Numerous management protocols aim to improve both posture and shape, however data related to normal back shape is quite scarce. The aim of this study was to investigate normal back shape in young adults, in order to produce normative values against which deformity could be defined. The Integrated Shape Imaging System (ISIS) was used to measure the three-dimensional back shape. A convenience sample of 48 normal adults, aged 18-28 volunteered to participate in this study. A small minority of individuals showed no curve (8%), 55% showed a single curve and the rest showed a double one. Right spinal asymmetry was more frequent than the left (77% to 52%). Mean values and 95% confidence intervals were 14.1 degrees (11.7 degrees-16.5 degrees) for upper Lateral asymmetry, 5.6 degrees (3.3 degrees - 7.9 degrees) for lower lateral asymmetry, 24.9mm (20.6mm -29.2mm) for thoracic kyphosis and 14.9mm (12.5mm -17.2mm) for lumbar lordosis. Increasing upper lateral asymmetry correlated with decreasing thoracic kyphosis (p=0.01). Maximum skin surface angle correlated positively with only upper lateral asymmetry (p<0.0001). Similar topographical interrelationships have been demonstrated in scoliosis. It is important that clinicians in relevant disciplines objectively assess all three dimensions of back shape, as our research shows that changes in one plane are associated with changes in the other two planes.

3-D measurement of posture and back shape using a low cost, portable system--a reliability study

The reliability and accuracy in the measurement of landmark points using a 3-D digitizer on a static back phantom are reported. The results show the systems clinical reliability as a low cost, portable and flexible method for recording back posture. Consistent results are demonstrated for a single measurer and good agreement was found between two measurers. Few intrinsic errors were found in the devices performance.

Sectional neuroanatomy of the lower limb II: leg and foot

The authors have produced a pair of articles that can be used to rapidly identify back, hip, and lower limb muscles and their innervation(s). This article presents the motor and sensory innervation of the lower limb by color-coding structures to match their peripheral nerves. It provides a companion summary table that allows prediction of unique patterns of denervation from 12 lesions sites.

Estimation of spinal deformity in scoliosis from torso surface cross sections

STUDY DESIGN

Correlation of torso scan and three-dimensional radiographic data in 65 scans of 40 subjects.

OBJECTIVES

To assess whether full-torso surface laser scan images can be effectively used to estimate spinal deformity with the aid of an artificial neural network.

SUMMARY OF BACKGROUND DATA

Quantification of torso surface asymmetry may aid diagnosis and monitoring of scoliosis and thereby minimize the use of radiographs. Artificial neural networks are computing tools designed to relate input and output data when the form of the relation is unknown.

METHODS

A three-dimensional torso scan taken concurrently with a pair of radiographs was used to generate an integrated three-dimensional model of the spine and torso surface. Sixty-five scan-radiograph pairs were generated during 18 months in 40 patients (Cobb angles 0-58 degrees ): 34 patients with adolescent idiopathic scoliosis and six with juvenile scoliosis. Sixteen (25%) were randomly selected for testing and the remainder (n = 49) used to train the artificial neural network. Contours were cut through the torso model at each vertebral level, and the line joining the centroids of area of the torso contours was generated. Lateral deviations and angles of curvature of this line, and the relative rotations of the principal axes of each contour were computed. Artificial neural network estimations of maximal computer Cobb angle were made.

RESULTS

Torso-spine correlations were generally weak (r < 0.5), although the range of torso rotation related moderately well to the maximal Cobb angle (r = 0.64). Deformity of the torso centroid line was minimal despite significant spinal deformity in the patients studied. Despite these limitations and the small data set, the artificial neural network estimated the maximal Cobb angle within 6 degrees in 63% of the test data set and was able to distinguish a Cobb angle greater than 30 degrees with a sensitivity of 1.0 and specificity of 0.75.

CONCLUSIONS

Neural-network analysis of full-torso scan imaging shows promise to accurately estimate scoliotic spinal deformity in a variety of patients.

The representation of the back in idiomatic expressions--do idioms value the body?

OBJECTIVE

Whilst investigating the influence of patients' representations on the impact of teaching in the back school, we took an interest in 1) the place of the back in the French idioms referring to the body; and 2) the meaning these idioms convey about the back.

METHODS

The idioms including body part terms were sought on the basis of a compilation of French idioms; it has to be noted that such a compilation, however excellent it may be, can only offer a partial view of lay conversation. Occurrence of body parts and of their connotations were assessed. Idioms were classified as positive, negative or neutral, keeping in mind the difficulties of a strict classification in such a field. Drawings were then performed on the basis of the results of the descriptive analysis.

RESULTS

Globally, idiomatic expressions offer a rather negative picture of the body or at least suggest that the body is prominently used to express negative ideas and emotions. This is particularly striking for the idioms associated with the back.

CONCLUSION

The analysis of idioms referring to the body allows us to 'see with our own eyes' another aspect of the representations of the body and the back, as they are conveyed in the French language.

Timing of activation of the erector spinae and hamstrings during a trunk flexion and extension task

STUDY DESIGN

Timing of activation of the hamstrings and erector spinae was assessed using surface electromyography.

OBJECTIVES

To investigate the influence of posture and movement speed during trunk flexion-extension on the flexion-relaxation response and trunk muscle activation patterns.

SUMMARY OF BACKGROUND DATA

The literature contains numerous reports on coactivity and synergistic behavior of major muscle groups during trunk flexion-extension. There are few reports on the timing of muscle activation.

METHODS

Six subjects were recruited for a training session and six biweekly test sessions. Ten surface electromyogram electrodes and a lordosimeter were used to record timing of lumbar motion and muscle recruitment in the hamstrings and at four sites in the thoracolumbar region. A 3 x 2 within-subject factorial design was used to test the effects of posture and speed on activation patterns.

RESULTS

Patterns of muscle activation were found to be dependent on posture and the direction of movement. The flexion-relaxation response was pervasive in the lumbar region but was less consistent at the T9 and hamstring sites. Significant differences in the delay between electromyogram activation and lumbar motion were found for the standing postures at initiation of extension, in which activation progressed in the caudad-to-cephalad direction.

CONCLUSIONS

The flexion-relaxation response is ubiquitous in the lumbar erector spinae and is present in the hamstrings and lower thoracic erector spinae, although not consistently in all subjects. In standing, timing of activation differed significantly by site in extension but not in flexion. Muscle activation patterns and flexion-relaxation were consistent over six biweekly test sessions.

Genome-wide scan for body composition in pigs reveals important role of imprinting

The role of imprinting in body composition was investigated in an experimental cross between Chinese Meishan pigs and commercial Dutch pigs. A whole-genome scan revealed significant evidence for five quantitative trait loci (QTL) affecting body composition, of which four were imprinted. Imprinting was tested with a statistical model that separated the expression of paternally and maternally inherited alleles. For back fat thickness, a paternally expressed QTL was found on Sus scrofa chromosome 2 (SSC2), and a Mendelian-expressed QTL was found on SSC7. In the same region of SSC7, a maternally expressed QTL affecting muscle depth was found. Chromosome 6 harbored a maternally expressed QTL on the short arm and a paternally expressed QTL on the long arm, both affecting intramuscular fat content. The individual QTL explained from 2% up to 10% of the phenotypic variance. The known homologies to human and mouse did not reveal positional candidate genes. This study demonstrates that testing for imprinting should become a standard procedure to unravel the genetic control of multifactorial traits.

Variability in three-dimensional measurements of back contour with raster stereography in normal subjects

Forty normal children with a mean age of 9.1 years were investigated by using a Quantec Spinal Image System (QSIS). The QSIS uses computerized raster stereography technology to acquire three-dimensional measurements of back contour. Within a 95-percentile confidence interval (a) coronal-plane QSIS angles ranged from 0.05 to 2.36 degrees; (b) transverse-plane QSIS angles ranged from 0.03 to 1.96 degrees; and (c) sagittal-plane QSIS angles ranged from 36.8 to 44.8 degrees. Trunk-alignment deviation ranged from 3.51 to 7.45 mm within a 95-percentile confidence interval. An intraobserver standard deviation of +/-4.2 degrees was noted across all angular metrics. Normal ranges of QSIS-determined values for a population of 40 children without clinical evidence of pathology are reported.

Relationship between muscle fiber composition and functional capacity of back muscles in healthy subjects and patients with back pain

Back muscles are important to the stability of the lumbar spine. Muscle fiber composition may give some indication of the functional capacity of these muscles. This review explores the relationship between muscle fiber composition and functional capacity of back muscles. The reference values for the type and size of the muscle fibers found in the back musculature of healthy subjects and patients with back pain are also presented. A high percentage of type I fibers, which are larger in size than type II fibers, has been found in back muscles at the thoracic and lumbar levels. This is in accordance with the postural function of these muscles. The diameter of type II fibers is smaller in females than males, which may partly explain the lesser strength and greater endurance capacity of back muscles in females. Due to the limited amount of pertinent data, no conclusive evidence is available regarding age-related changes in muscle fiber composition in the musculature of the back. In patients with lumbar disorders, pathological changes and selective atrophy of type II fibers are seen, and these can be changed with adequate exercises. Further research is suggested to address issues related to gender, age, back pain, and exercise and their effects on the apparent back muscle fiber composition.

Quantification of cosmesis for patients affected by adolescent idiopathic scoliosis

The aim of this study was to quantify cosmesis for patients affected by adolescent idiopathic scoliosis. Eight nonmedical judges were asked to examine photographs of 40 patients with adolescent idiopathic scoliosis, and to score the cosmesis of their backs without any information. Various parameters were measured from radiographs, Moiré topographies, and physical measurements of patients, and these were compared with the cosmetic scores of the judges. The judges' scoring proved to be reliable. The cosmetic scores showed a significant correlation with the Cobb angle, hump severity, asymmetry of the waist line, circumference of the chest, and obesity. Multivariate analysis produced equations to calculate the cosmetic score for the back. This equation is thought to have a useful clinical application.