Male Clavicles Research Articles

Morphometry and Sexual Dimorphism of the Human Clavicle in South Indian Population

Background: In forensic anthropology, determining an individual's sex is the fundamental criteria of identification, but this is a tough task that gets considerably more difficult when only a single bone, such as the clavicle, is available. In physical anthropology, determining the sex of a deceased individual is a fundamental prerequisite. Physical anthropologists have gotten more concerned about the difficulties of human identity in recent years. Traditional techniques of sexing bone are subjective and ineffective when absolute sexing precision is desired, hence this study. Methods: Measurement of clavicular length and circumference using an Osteometric board or sliding and Vernier Callipers product from 1128 dry clavicles of unknown sex and age procured from various medical institutions and departments of anthropology in south Inda. Length, inner angle, outer angle, the sum of angles, inner segment, middle segment, outside segment, width at the inner end at an inner angle, least width at conoid tubercle, at the outer end, and mid circumference have all been measured. Results and Discussion: The male mid-shaft circumference is 38.0±0.5mm on the right side and 36.5±0.5mm on the left side, whereas the female mid-shaft circumference is 31.4±0.3mm on the right side and 31.4±0.6mm on the left side. The length of the left clavicle is greater than the length of the right collarbone. The curvature of the right collarbone is higher than that of the left, resulting in a shorter right bone than the left. The clavicle of males has a higher mean across all parameters than females. Male clavicle length is more than female clavicle length, midshaft circumference is less in females than males, and breadth at an inner angle is shorter in females than men, all of which are statistically significant. The Mid-shaft Circumference as a sex-determination metric is statistically significant in differentiating the clavicle's sex. This delivers a better result than clavicle weight since clavicle weight fluctuates with age and the health state of the individual. Male clavicles have a larger Mid-shaft Circumference than female clavicles. KEY WORDS: Anthrozoology, Clavicle, Morphometry, Skeletal Remains, Mid-Shaft Circumference.

Biomechanical evaluation of an intramedullary clavicle screw in simple oblique and butterfly wedge fractures.

This biomechanical study evaluates the performance of a solid titanium-alloy intra-medullary (IM) clavicular screw in torsion and cantilever bending in cadaveric clavicle specimens with simulated simple oblique and butterfly wedge midshaft fractures. Thirty-two fresh-frozen male clavicles were sorted into six experimental groups: Torsion Control, Torsion Simple Oblique Fracture, Torsion Butterfly Wedge Fracture, Bending Control, Bending Simple Oblique Fracture, and Bending Butterfly Wedge Fracture. The experimental groups were controlled for density, length, diameter, and laterality. All other samples were osteotomy-induced and implanted with a single 90 mm × 3 mm clavicle screw. All groups were tested to physiologically relevant cutoff points in torsion or bending. There were no statistically significant differences in the performance of the oblique and butterfly wedge fracture models for any torsion or bend testing measures, including maximum torsional resistance (p = 0.66), torsional stiffness (p = 0.51), maximum bending moment (p = 0.43), or bending stiffness (p = 0.73). Torsional testing of samples in the direction of thread tightening tended to be stronger than samples tested in loosening, with all groups either approaching or achieving statistical significance. There were no significant differences between the simple oblique or the butterfly-wedge fracture groups for any of the tested parameters, suggesting that there is no difference in the gross biomechanical properties of the bone-implant construct when the IM clavicle screw is used in either a simple midshaft fracture pattern or a more complex butterfly wedge fracture pattern.

Determination of Sex From Adult Clavicle – An Autopsy based Regional Study

Background: Studies on “identification of the sex from clavicle bone alone” are carried out by various workers all over the world.But, it is well known fact that the racial and geographical differences exist in the metrical measurement of all the bones including clavicles, as the determination of sex is a population specific phenomenon. Matrials and Methode : This study was conducted on100 male clavicles and 100 female clavicles collected from identified corpses brought for medicolegal autopsy at Department of Forensic Medicine Govt. Medical College Calicut. Measured the various parameters and compared with previous studies. RESULTS :In the present study, the length , midclavicular circumference and weight of male clavicles weres more than female clavicles. The female clavicle has its length around 86% of male clavicle and mean MCC around 83% of the male clavicles.. Robustness index also calculated, mean robustness index was 23.11, and could identify only 76 % males and 64% females by this. CONCLUSION:In order to establish the anthropometric standards, and for the evaluation of the same from time to time, the continuance of such studies in defined geographical areas over a particular period of time is needed.

Evidence of Costoclavicular Joint as A Synovial Joint

Introduction: The present study was conducted to note the osteological evidence of a synovial joint between clavicle and first rib in Indians. Material and Methods: The present study was conducted on 310 pairs of adult clavicles and first ribs, out of which 210 pairs were males and 100 pairs were females obtained from the Anatomy department of Pt. B. D. Sharma Postgraduate Institute of Medical Sciences, Rohtak. The articular facets were studied and measured with the help of a sliding Vernier caliper (Micropole). Results: Among 210 pairs (420 no.) of male clavicles examined, 6 clavicles (2.86%) had a circumscribed smooth articular facet with well-defined margins. Out of these 6 clavicles, 3 (1.43%) were of right side and 3(1.43%) were of left side. A corresponding facet was present on the first ribs of the same skeletons. The facets were found to be present unilaterally and that too in males only. The measurements of the articular facets on the rhomboid area of the clavicles and ribs were-the average length, width and elevation was 7mm, 5.4mm and 2.2mm respectively. Conclusion: These articular facets on the rhomboid area of clavicles and first ribs are osteological evidence of a synovial articulation between clavicle and first rib.

Morphometric Analysis of the Clavicles in Chinese Population.

The clavicle has a complex geometry that makes plate fixation technically difficult. The current study aims to measure the anatomical parameters of Chinese clavicles as reference for plate design. One hundred clavicles were analyzed. The clavicle bone model was reconstructed by using computed tomography images. The length, diameters, and curvatures of the clavicle were then measured. The female clavicle was shorter, more slender, and less curved in lateral part than the male clavicle. There was a positive relationship between height and clavicle parameters except lateral curve and depth. The measurements of Chinese clavicles were generally smaller than Caucasians. The clavicle curves were correlated with the bone length; thus consideration of the curve variations may be necessary as designing size distribution of clavicle plate.

Curvatures and Medullary Canal of the Clavicle Among an Egyptian Population: A three Dimensional Computed Tomography Study

Background: Clavicle is the most frequently fractured bone in human skeleton. Fractures treated nonoperativelyshowed higher rate of non-union or malunion. Operative treatment have superior results overthe non-operative treatment, and include two approaches; external fixation or internal fixation. Externalfixation may be cosmetically displeasing and uncomfortable. Internal fixation is accompanied by a higherrate of cure with lesser complications, however the shape and size of the medullary canal of the clavicle canbe a prohibiting factor making the placement of intramedullary devices difficult.Aim of work: The present work was designed to study the length, the curvatures as well as the dimensionsof the medullary canal of the clavicle among Egyptians using three dimensional computed tomography.Material and Methods: This study was carried on one hundred clavicles. CT scan of the chest with coronaland sagittal reformatting and 3D reconstruction of the clavicle was done.Results: The length of male clavicles was longer than female clavicles. Left clavicles were shorterthan right clavicle in both sexes. The medial as well as the lateral angle of the left clavicle was greaterthan that of the right clavicle in both sexes. The height and width of the medullary canal of the claviclewere generally greater in males than in females.Conclusion: Computed tomography imaging has been shown to be an accurate method for describingthe anatomy of the clavicle. Data could be used to determine whether the anatomy of the clavicle and itsmedullary canal were suitable for intramedullary fixation.

The anatomy of the clavicle

The clavicle has a complex osteologic structure that makes morphological analysis extremely difficult. A three-dimensional study was conducted to examine the anatomical variations and characteristics of the bone. Sixty-eight human cadaver clavicles were dissected, CAT-scanned, and reconstructed. An automated parameterization and correspondence shape analysis system was developed. A new length, designated as centerline (CL) length, was defined and measured. This length represents the true length of the clavicle. The endpoint length was measured as the distance between two endpoints. The width and curvature were measured in the axial (AX) and frontal (FR) plane and defined along the CL. Next gender and side characteristics and variations were examined. The mean CL length was 159.0 ± 11.0 mm. The mean endpoint length was 149.4 ± 10.3 mm, which was statistically significantly shorter than the CL. The male clavicle was significantly longer (166.8 ± 7.3 mm vs. 151.0 ± 8.2 mm), wider (14.6 ± 1.5 mm vs. 12.7 ± 1.3 mm lateral FR plane, 25.9 ± 4.1 mm vs. 23.5 ± 3.0 mm lateral AX plane and 24.7 ± 2.8 mm vs. 22.8 ± 2.8 mm medial AX plane), and more curved (10.8 ± 2.8 mm vs. 8.6 ± 2.3 mm medial and 10.5 ± 3.3 mm vs. 9.1 ± 2.5 mm lateral) than the female one. Left clavicles were significant longer (159.8 ± 10.9 mm vs. 158.0 ± 11.2 mm) than right clavicles. A novel three-dimensional system was developed, used and tested in order to explore the anatomical variations and characteristics of the human clavicle. This information, together with the automated system, can be applied to future clavicle populations and to the design of fixation plates for clavicle fractures.

Development and validation of a subject-specific finite element model of a human clavicle

This study aimed to develop and validate a finite element (FE) model of a human clavicle which can predict the structural response and bone fractures under both axial compression and anterior–posterior three-point bending loads. Quasi-static non-injurious axial compression and three-point bending tests were first conducted on a male clavicle followed by a dynamic three-point bending test to fracture. Then, two types of FE models of the clavicle were developed using bone material properties which were set to vary with the computed tomography image density of the bone. A volumetric solid FE model comprised solely of hexahedral elements was first developed. A solid-shell FE model was then created which modelled the trabecular bone as hexahedral elements and the cortical bone as quadrilateral shell elements. Finally, simulations were carried out using these models to evaluate the influence of variations in cortical thickness, mesh density, bone material properties and modelling approach on the biomechanical responses of the clavicle, compared with experimental data. The FE results indicate that the inclusion of density-based bone material properties can provide a more accurate reproduction of the force–displacement response and bone fracture timing than a model with uniform bone material properties. Inclusion of a variable cortical thickness distribution also slightly improves the ability of the model to predict the experimental response. The methods developed in this study will be useful for creating subject-specific FE models to better understand the biomechanics and injury mechanism of the clavicle.

Age estimation from clavicular epiphyseal union sequencing in a Northwest Indian population of the Chandigarh region

Medial clavicular epiphysis is the long bone epiphysis to fuse last and therefore, is useful for estimating age in the post-pubertal period. Age estimation was done from clavicles obtained from 343 cadavers (252 males and 91 females) of known age. The data was subjected to statistical analysis to see whether the difference obtained in the various ages was significant or not. Commencement of fusion was seen as early as 18 years of age in both male and female clavicles. No clavicle showed complete fusion until the age of 22 years. Complete fusion of the medial end of the clavicle was seen latest at 32 years in the male clavicles while the same was observed at 31 years in the female bones, i.e., the medial epiphysis of female clavicles fused one year earlier than their male counterparts. Advanced stages of clavicular epiphyseal union were seen in most of the clavicles after 24 years of age in females and 23 years of age in males. No significant difference was noticed in both sexes for the right and left clavicles as regards to the occurrence of various stages of epiphyseal union.

Studies on the biomechanics of the human clavicle (author's transl)

64 non preserved and 35 preserved clavicles were fractured in three defined positions in a bending test by a tension testing machine with electronic measurement of force. 30 non preserved bones were fractured in an axial infraction test. Force-deflection-diagrams were registered, and the values of maximum load, breaking load, ultimate deflection and energy were correlated to cross section and thickness of compacta. The significantly greater non preserved male clavicles are loadable at a higher level (medium breaking load about 1200 N) than female bones (medium breaking load abut 800 N). The breaking energy of the more flexible female clavicles is about 30% lower than those of males whereas elastic modulus of female clavicles is significant greater. Preservation has a significant influence on biomechanical properties of bones: ultimate deflection decreases; breaking energy, ultimate stress and elastic modulus increase. Breaking load is greatest in the middle portion of the clavicle, while deflection is greatest in the sternal portion. Removal of periosteum causes lower breaking load, deflection, ultimate stress and elastic modulus as well. With axial load clavicle fractures occur most frequently between middle and sternal third.

Anatomy of the clavicle and the intramedullary nailing of midclavicular fractures

Intramedullary fixation is used increasingly to treat clavicular fractures. Anatomical variations in the clavicle of relevance to this procedure are analyzed. The length, diameters and curvature of the clavicle were measured in 196 specimens from the dissecting room. The calcium bone density was analyzed in 300 cross-sectional samples of 100 specimens. The thickness of cortical and medullary bone of 70 slices was analyzed from freshly plastinated clavicles with implants in place. The female clavicle was shorter, less curved, and had a lower concentration of calcium than the male clavicle. Measurement of cortical thickness showed a mean value of 1.05 +/- 0.23 mm at the most sternal measuring point, 2.05 +/- 0.29 mm at the midpoint of the clavicle, and 0.95 +/- 0.35 mm at the acromial end. The thinnest regions were the medial ventral cortex and the dorsal acromial cortex. These measurements explain clinical observations on nail perforation. The diameter of the medullary canal measured 6.7 +/- 2.6 mm at its narrowest part, so that reaming (i.e., predrilling the medullary canal) prior to 3.5 mm titanium nail insertion is not necessary. The main difficulties encountered when placing a nail are secondary to the S-curvature of the clavicle. In 80% of fractures, the break is located at the narrowest diameter of the medullary canal. Thus, the clavicle displays definite gender- and side-specific anatomical features in terms of length, diameter, curvature, and calcium concentration. These should be considered when performing intramedullary fixation.

Determination of sex from the clavicle and scapula in a Guatemalan contemporary rural indigenous population.

The clavicle has been described as a useful bone for the metric determination of sex of human skeletal remains in a contemporary, predominantly white, North American forensic sample. In this article, measurements of clavicle and scapula are provided for a contemporary Guatemalan rural indigenous sample of forensic origin. Maximum length and circumference at midshaft of the clavicle, and height and width of the glenoid fossa of the scapula, were measured in 35 female and 62 male clavicles, and in 38 female and 65 male scapulae. Discriminant function analysis was used to study sexual dimorphism in this population with a classification purpose. Leave-one-out method (jackknife) matrices produced classification success rates ranging from 85.6% to 94.8%. A comparison with the North American forensic sample showed low percentages of correctly sexed Guatemalan male clavicles, ranging from 29.4% to 54.9%. The choice of an appropriate standard for the metric determination of sex is a crucial step in forensic anthropology.