Comparison of imaging planes during CT-based evaluation of clavicular ossification: a multi-center study.

Determining the ossification stage of the medial clavicular epiphysis by computed tomography represents the currently recommended methodology for the question of whether a living individual has completed the 18th or 21st year of life. In the present study, thin-slice CT scans of 1078 sternoclavicular joints were reconstructed in axial and coronal image series and evaluated according to the two classification systems established for age diagnostics using the clavicle. Both image series (axial and coronal) were analyzed separately. When comparing the results of axial and coronal view, a different ossification stage was found in 35.6% of the clavicles. The results suggest an influence of the imaging plane on the process of stage determination. In order to further approximate the three-dimensional and asymmetrical structure of the epiphyseal ossification center, the usage of at least two different reformation types may be recommended. In practice, only those reference studies should be applied which exactly employed the same number and orientations of the reformation types that are going to be used in the respective routine case.

Projection radiography of the clavicle: still recommendable for forensic age diagnostics in living individuals?

As superimposition effects often impede the evaluation of the ossification status of the medial clavicular epiphysis in standard posterior-anterior (PA) radiographs, additional oblique images (right anterior oblique, RAO, and left anterior oblique, LAO) are currently recommended to allow for reliable stage assessments. The present study examines the influence of the radiographic projection type on stage determination. To this end, 836 sternoclavicular joints were prospectively obtained during forensic autopsies of bodies aged between 15 and 30 years. Subsequently, three different radiographs (PA, RAO, and LAO) were taken from each specimen and separately evaluated as to the developmental stage of the medial clavicular epiphysis. A forensically established five-stage classification system was used. In 25 % of the cases, the medial clavicular epiphysis depicted in an oblique projection showed a different ossification stage than in the PA projection. In at least 10 % of the cases, a higher ossification stage was observed which would have significant disadvantages in criminal proceedings (ethically unacceptable error). In conclusion, the usage of the current radiographic reference data, which rely upon chest radiographs taken as PA projections, appears to be inadmissible for oblique projections. Projection radiography of the clavicle can therefore no longer be recommended for forensic age estimation practice. As to the question of whether an individual has achieved the age of 18 or 21, computed tomography of the clavicle must be regarded as the exclusive method of choice.

The value of sub-stages and thin slices for the assessment of the medial clavicular epiphysis: a prospective multi-center CT study.

The clavicle plays an important role for forensic age estimation in living individuals, particularly with regard to the age of majority. The present prospective study aims to evaluate the age-dependent ossification process of the medial clavicular epiphysis in order to establish the clavicular sub-stages introduced in 2010 as well as the advantages and possibilities of thin-slice computed tomography (CT). For this purpose, 0.6 mm thin-slice CT scans of sternoclavicular joints of 572 bodies aged between 10 and 40 years were evaluated by means of two complementary classification systems: a five-stage system and a sub-staging system for the main stages 2 and 3. Assessment was possible in 493 cases. The results for stages 4 and 5 are in line with previous studies that found the ages of 21 years and 26 years, respectively, as minimum ages for these stages. Sub-stage 3c was first found at the age of 19 years in both sexes, thereby corroborating the value of this sub-stage as to statements about the age of majority. In comparison to other CT studies, stage 3a was first observed ~1 year earlier (16.4 years in males and 15.5 years in females). Stage 2c only occurred in 3 cases. In conclusion, the data corroborate the significance of diagnosing sub-stages as well as the value of thin-slice CT. For forensic practice, the concomitant and complementary use of both classification systems applied in this study can be recommended.

Anatomy and biomechanics of the acromioclavicular and sternoclavicular joints.

The acromioclavicular and sternoclavicular joints have important soft-tissue static constraints that, based on biomechanical studies, imply a great deal of stability. The infrequency of significant symptoms following dislocations of these joints certainly highlights the fact that the dynamic muscle support is also very important. In performing resections of these joints for degenerative disease, our goal should be to preserve these important ligamentous supports by minimizing the amount of bone excised, as this seems to optimize results [84]. Precise isometric reconstruction of these complex, three-dimensional ligamentous structures merits further investigation in the laboratory and clinical settings.

Histologic comparison of the costochondral, sternoclavicular, and temporomandibular joints during growth in Macaca mulatta.

The costochondral joint (CCJ) is commonly used to replace defective mandibular condyles in children for the restoration of normal temporomandibular (TMJ) growth and function. However, continued and harmonious growth following rib grafting is the exception rather than the rule. This may be due to the differences in the growth characteristics of the costal cartilage and the condyle. A joint that is similar both developmentally and structurally to the TMJ is the sternoclavicular joint (SCJ). The purpose f this study was to describe histologically the SCJ and CCJ during growth in Macaca mulatta and to compare the histomorphologic features with those of the TMJ. Costochondral and sternoclavicular joints were obtained from infant, juvenile, adolescent, and adult Macaca mulatta. The histologic sections were compared with mandibular condyles of the same ages available in our laboratory. The results indicate that the TMJ and SCJ are very similar morphologically throughout the growth period. The clavicular head contained layers of cartilage typical of the mandibular condyle, i.e., articular, prechondroblastic, chondroblastic, hypertrophic, and endochondral ossification layers, at each age during growth. Like those in the condyle, the hypertrophic cartilage cells were arranged in an apparently random, noncolumnar fashion. The CCJ, however, did not resemble the condyle but appeared to be more similar to the growth plate in a long bone epiphysis during growth. The results of this investigation indicate that the SCJ may be more suitable for mandibular condylar replacement than the CCJ.

Radiology of postnatal skeletal development. III. The clavicle.

Thirty-one pairs of clavicles obtained from human cadavers ranging in age from full-term stillborn to fourteen years were studied morphologically and radiographically. Specimen roentgenography using air/cartilage interfacing demonstrated the osseous and cartilaginous portions of the epiphyses. Overall longitudinal growth appeared to occur to a greater degree in the sternal end, which also developed a secondary ossification center. No comparable ossification was seen in the acromion. The curve patterns differed in the acromial and sternal ends. The sternoclavicular joint has a meniscus throughout postnatal development. This was demonstrated by air arthrography. Finally, the sternoclavicular joint was dislocated anteriorly and posteriorly to duplicate trauma to this region. Roentgenographic aspects of development are discussed and illustrated to provide a reference index.