Study of age dependence of epiphyseal ossification of the hand skeleton

Radiological analysis of the hand skeleton is a key pillar of forensic age diagnostics in living subjects undergoing criminal proceedings. The present study investigated whether ossification stage classification of selected epiphyses of the hand could provide added value to hand radiograph analysis. Hand radiographs from 265 male and 164 female subjects aged 10–18years old who had been X-rayed due to traumatological indications were therefore assessed. Epiphyseal ossification of selected elements of the hand skeleton (ulna, radius and third metacarpal, basal phalanx, mesophalanx and telephalanx) was graded based on the criteria of the five-stage classification system of Schmeling et al. (Int J Legal Med, 118:5–8, 2004) for clavicular epiphyseal cartilage. Stage 5 (absence of the epiphyseal scar) does not occur in the radius of men before the age of 18. Stage 5 can therefore be regarded as a potential parameter for valid determination of a minimum age of 18 years for forensic age estimation in criminal proceedings.     

Magnetic resonance imaging of the clavicular ossification

Assessment of the degree of ossification of the medial clavicular epiphyseal cartilage is of vital importance in forensic age diagnostics of living individuals aged more than 18 years. To date, reference studies on the assessment of clavicular ossification using imaging procedures only relate to conventional radiography and computed tomography (CT). In this study, magnetic resonance (MR) scans of 54 sternoclavicular joints of bodies aged between 6 and 40 years were evaluated prospectively. All of the examined medial clavicular epiphyseal cartilages permitted an assessment of the degree of ossification. Stage 2 was first observed at the age of 15.0 years, the earliest age at which stage 3 was observed was 16.9 years, and stage 4 was first observed at the age of 23.8 years. The observed age intervals of the respective degrees of ossification correspond to the known data from X-ray and CT scan examinations. The achieved results should be examined with a larger number of cases. A modified examination protocol is required for the MR examination of the medial clavicular epiphyseal cartilage for the purpose of forensic age diagnostics of living individuals.     

Skeletal age determination of the hand: a comparison of methods

Until final completion of maturation processes at the age of approximately 18 years, determination of the skeletal age of the hand plays a central role in forensic age diagnostics in living persons in criminal proceedings. In this process, assessment of hand radiographs relies primarily on the stage of development of the epiphyseal nuclei, the increase in size of the individual bones and of the hand skeleton as a whole, changes in the shape of the various skeletal elements and ossification of the epiphyseal plates. To achieve this, there are a variety of methodological approaches based on two different fundamental principles. The methods proposed by Greulich and Pyle, Thiemann et al. and Gilsanz and Ratib rank among the so-called atlas techniques, whilst the methods proposed by Tanner et al. and Roche et al. are classified as so-called bone-specific techniques. In order to be applicable in the field of criminal procedure, the methods of estimating the skeletal age of the hand developed with clinical aspects in mind must satisfy the demands of a high degree of estimate accuracy and good reproducibility of the estimated results. In the course of the present study, a study population of 92 persons was used to compare the above-mentioned atlas and bone-specific techniques for determining hand skeleton age in view of these qualitative criteria. Estimate accuracy was studied using Pearson’s correlation coefficients, and weighted kappa coefficients were determined for studying the intra-and interobserver agreement of an estimate result. In the inter-method comparison, a basically good agreement was shown between the skeletal ages and the chronological age of the test persons on the one hand and the skeletal age diagnoses of one or of two examiners on the other. No general advantage of the methodological approach of the bone-specific technique was discernible in the course of comparison; in the female gender, particularly, the RUS2 and RUS3 score of the method of Tanner et al. proved unfavourable. For age estimation practice in criminal proceedings, the atlas methods of Greulich and Pyle and Thiemann et al. are particularly recommendable.     

The use of magnetic resonance imaging to examine ossification of the proximal tibial epiphysis for forensic age estimation in living individuals

The establishment of radiation-free examination procedures in the field of forensic age diagnostics in living persons is to be considered of special scientific interest so as to minimize necessary exposure to X-rays while facilitating additional assessment of skeletal development in all cases. To this end, the advantages offered by magnetic resonance imaging in securing a practical application which is as unrestricted and complication-free as possible should be among the methods exploited in investigating such indicators of skeletal maturity. Within the framework of a retrospective study, we investigated the ossification status of the proximal tibial epiphysis on the MRI scans of 124 females and 166 males aged between 10 and 30 years. All the images had been generated on a 3.0 T scanner using a T1-weighted turbo spin-echo sequence. When evaluating the ossification stage, a combination of modified classifications proposed by Schmeling et al. and by Kellinghaus et al. was used. The statistical evaluation included calculation of a variety of measures to describe specific ossification stages as well as kappa coefficients to assess intra- and inter-observer agreement on diagnoses of individual stages. In forensic contexts, completion of the 14th year of life can be adequately evidenced in females with an ossification stage IV according to Schmeling et al. and in males with an ossification stage III c according to Kellinghaus et al. or an ossification stage IV according to Schmeling et al. In forensic contexts, the presence of an ossification stage IV according to Schmeling et al. can prove that the age of 16 years has been exceeded only in the male sex, whereby for age estimation purposes the diagnosis should be in line with other skeletal maturity indicators. The results available displayed a high degree of intra- and inter-observer agreement. Examination of the ossification status of the proximal tibial epiphysis using magnetic resonance imaging represents an effective additional tool for use in radiation-free forensic age diagnostics in living persons.     

Age dependence of epiphyseal ossification of the distal radius in ultrasound diagnostics

By determining the ossification stage of the distal radial epiphysis, it is possible to gain important information to help clarify the question of whether various legally relevant age limits have been exceeded. Any examination of the hand by means of projection radiography such as that used in conventional skeletal age diagnostics is strictly regulated for reasons of radiation hygiene. In many areas of the law, there are no basic legal provisions authorising the performance of X-ray examinations. The present study examines the applicability of ultrasound diagnostics in assessing ossification processes in the distal radius. To this end, the ossification stages of the distal radial epiphysis were determined in 306 female and 309 male study participants aged between 10 and 25 years. In the female gender, ossification stage III was determined at an age of 13.4 years at the earliest, and ossification stage IV at 15.0 years at the earliest. In the male gender, ossification stage III was not observed until 14.3 years, and ossification stage IV not until 15.2 years. In the practice of forensic age estimation in living persons, sonographic examination of the distal radius in areas of application with no legal basis for authorising X-ray examinations makes it possible to improve the accuracy of age diagnosis by including criteria of skeletal maturation. In view of the existing legislative basis for the use of X-rays on human subjects, the exposure of individuals to radiation can be minimised.     

Ossifikationsvorgänge des Trochanter major femoris

Background

Despite a relatively minimal level of radiation exposure, the use of x-ray radiation for the forensic estimation of chronological age of individuals is often subject to public criticism. In the recent past this has encouraged the scientific investigation of alternative imaging procedures with which the radiation-free assessment of the skeletal maturation process is possible.

Aim

The present study investigated the applicability of ultrasound diagnostics for assessing the ossification processes of the epiphysis of the greater trochanter.

Material and methods

For this purpose the epiphyseal ossification stages of 307 female and 309 male test persons between 10 and 25 years of age were determined.

Results

In the female subjects ossification stage II was found at the earliest at 10.1 years (x??=?12.2 years), ossification stage III at the earliest at 12.5 years (x??=?15.1 years) and ossification stage IV at the earliest at 13.4 years (x??=?20.8 years). In the male subjects ossification stage II was observed from 10.0 years (x??=?12.8 years), ossification stage III from 13.8 years (x??=?16.0 years) and ossification stage IV from 14.5 years (x??=?21.3 years).

Conclusion

With the legal basis as it stands at present, the sonographic examination of the femoral trochanter epiphysis allows individual radiation exposure to be kept to a minimum in the use of x-rays on humans in the forensic age estimation practice of living individuals. In areas of application where there is no legal authorization basis for radiological examinations, including a skeletal maturity criterion can increase the accuracy and reliability of age estimation.     

Qualitätssicherung von Altersgutachten

Since 2001 the Study Group on Forensic Age Diagnostics of the German Society of Legal Medicine has carried out annual proficiency tests to assure the quality of expert opinions on age. A report is given on the 10th proficiency test from 2012 in which 34 study groups from 9 countries participated. The results of this proficiency test demonstrated that the Study Group has made significant progress in its efforts to harmonise the methods used in forensic age diagnostics in living individuals. None of the experts fulfilled the exclusion criterion of an age diagnosis which was too high; however, it must be noted critically that hand skeleton age as well as the stages of wisdom tooth mineralisation and clavicular ossification were determined incorrectly by some participants. It is recommended that where appropriate, radiologists and dentists should be integrated into the review process and that experienced specialists should be consulted in difficult cases of clavicular ossification assessment.     

Enhanced possibilities to make statements on the ossification status of the medial clavicular epiphysis using an amplified staging scheme in evaluating thin-slice CT scans

Thin-slice computed tomography provides the imaging modality of choice in analysing the ossification process of the medial clavicular epiphysis for the purpose of forensic age diagnostics in the living in the course of criminal proceedings. The classification of the ossification stages by Schmeling et al. compass the emergence of an epiphyseal ossification centre (stage 2), the partial fusion of the epiphysis with the metaphysis (stage 3), the complete fusion of these osseous elements including a visible epiphyseal scar (stage 4), and the complete fusion without a visible epiphyseal scar (stage 5). In the present study, each of the ossification stages 2 and 3 was divided into an early, intermediate and late phase. The authors evaluated the thin-slice CT scans of 185 patients aged between 13 and 26 years. In all these cases, a stage 2 or 3 had been determined in a previous study. The late stage 3, which is characterized by a fusion between metaphysis and epiphysis completing more than two thirds of the former epiphyseal gap, first appeared at age 19 in both sexes. If a late stage 3 is found, it is therefore possible to substantiate that an individual has already reached the legally important age threshold of 18 years.     

Sonographic evaluation of apophyseal ossification of the iliac crest in forensic age diagnostics in living individuals

Due to the requirement to minimise exposure to radiation, it is desirable to develop non-ionising imaging procedures for the analysis of skeletal maturation for forensic age diagnostics in living individuals. The present pilot study analyses the applicability of ultrasound examinations for the evaluation of apophyseal ossification of the iliac crest. With reference to the sonographic staging of clavicular ossification, the maturation stages of the iliac crest apophysis of 23 male and 16 female subjects, aged 11–20 years, were determined. Ossification stage I occurred in the male subjects at a minimum age of 15.7 years. Ossification stage II was diagnosed in boys at a minimum age of 14.1 years and in girls at a minimum age of 11.7 years. The earliest observation of ossification stage III was at a chronological age of 16.2 years in males and 15.2 years in females. The earliest age of occurrence of ossification stage IV was at least 18.0 years in male test persons and at least 17.1 years in female test persons. The results obtained should be reassessed in a larger number of cases. It is to be expected that sonographic examination of the iliac crest apophysis will become established as a valid and efficient method for forensic age diagnostics in living individuals.     

Forensische Altersdiagnostik bei lebenden Jugendlichen und jungen Erwachsenen

In recent years forensic age diagnostics in living adolescents and young adults has become more and more important. In Germany the legally relevant age limits are 14, 16, 18, and 21 years of age. In accordance with the recommendations of the Study Group on Forensic Age Diagnostics (Arbeitsgemeinschaft für Forensische Altersdiagnostik, AGFAD), the following tests should be performed in combination for age estimation: a physical examination, an X-ray examination of the hand, a dental examination including an orthopantomogram as well as an additional X-ray examination of the clavicles with completed development of the hand skeleton. Without an authorization for an X-ray examination the spectrum of methods is limited to a physical examination and determination of the dental status. Based on the use of radiation-free imaging procedures a clear improvement in the reliability of these age estimates is expected. The influence of ethnicity and socioeconomic status on the examined age characteristics must be considered in the assessment.     

Comparative analysis of the applicability of the skeletal age determination methods of Greulich–Pyle and Thiemann–Nitz for forensic age estimation in living subjects

Evaluation of hand ossification is a main pillar of radiological age diagnosis in living subjects. In the present study, we comparatively assessed the Greulich–Pyle and Thiemann–Nitz methods for accuracy of age estimation and degree of acceleration in the respective reference populations. For this, the skeletal age of 649 hand X-rays from German subjects aged 1–18 years was determined by both methods. Accuracy of the age estimates was determined based on regression and measures of certainty. In terms of accuracy, both methods seem to be equally well suited for forensic age diagnostics. The degree of acceleration in the reference populations for the two methods was calculated as the mean difference between the estimated skeletal age and the actual age of a test subject. Compared to the Greulich–Pyle population, the Thiemann–Nitz population was accelerated by 0.44 years in both male and female subjects. When an expert opinion is required and one cannot exclude the possibility that the investigated subject may come from a population with a high acceleration status, the Thiemann–Nitz method should preferably be used to prevent overestimation of age.     

Applicability of the skeletal age determination method of Tanner and Whitehouse for forensic age diagnostics

The present paper analyses the applicability of the clinically prevalent skeletal age determination method of Tanner and Whitehouse for forensic age estimation in living individuals. For this purpose, the hand X-rays from 48 boys and 44 girls aged 12-16 years were evaluated retrospectively. The minima and maxima, the mean values with their standard deviations as well as the medians with upper and lower quartiles, are presented for the skeletal ages 12-16 years estimated by the TW2 and TW3 methods. In the legally relevant skeletal age group 14-16 years, the differences between the skeletal age and the mean value of the chronological age were between -0.1 and +1.4 years for the TW2 method. For the TW3 method, the differences between the skeletal age and the mean value of the chronological age were between -0.4 and +0.2 years in the relevant age group. Due to the risk of serious overestimations, the TW2 method seems to be unsuitable for forensic age diagnostics. The application of the TW3 method for forensic age estimations can be recommended.     

Ultrasound studies on the time course of clavicular ossification

When preparing forensic age estimates for living subjects over 18 years of age, it is crucial to evaluate the stage of ossification of the medial clavicular epiphysis. The establishment of radiation-free imaging techniques for assessment of clavicular ossification would be desirable in order to reduce the radiation exposure associated with forensic age estimations. In the present study, 84 right clavicles of test subjects 12–30 years of age were prospectively evaluated by means of ultrasound. Ossification stage classification was possible in 80 of the 84 medial clavicular epiphyses studied. In the remaining cases, stage classification was not possible due to the presence of developmental anomalies. The earliest ages at which the respective ossification stages were observed were 17.1 years for stage 2, 16.7 years for stage 3, and 22.5 years for stage 4. The age intervals observed for the ossification stages are consistent with the known data from radiological and computed tomography assessments. The present study results should be confirmed in a larger number of cases and with analysis of observer variability. Evaluation of medial clavicular epiphyseal ossification by ultrasound could ultimately be a rapid and economic non-ionizing diagnostic imaging procedure for forensic age estimation.     

Effects of ethnicity on skeletal maturation: consequences for forensic age estimations

An X-ray of the hand is an important method in forensic science for estimation of the age of juvenile suspects with uncertain date of birth. Relevant X-ray standards for evaluation of skeletal maturity are available for white US Americans as well as for North and Central Europeans. The applicability of these standards to members of ethnic groups different from the reference population has been the subject of controversial discussion. More than 80 publications were analysed with the view to finding out whether skeletal maturation is affected by ethnic identity. It was concluded that skeletal maturation takes place in phases which are identically defined for all ethnic groups. Time-related differences in passing those stages of skeletal maturation within the relevant age group appear to be unaffected by ethnic identity. It is the socio-economic status of a given population which is of decisive importance to the rate of ossification. The application of X-ray standards to individuals of a socio-economic status lower than that of the reference population usually leads to underestimation of that person’s age. In terms of criminal responsibility, this is of no adverse effect on the person concerned. Received: 25 February 1999 / Received in revised form: 6 August 1999     

Magnetic resonance imaging of the proximal tibial epiphysis: could it be helpful in forensic age estimation?

There is an increasing demand for age estimations of living persons who are involved in civil and criminal procedures but lack a valid birth certificate indicating their date of birth. Several studies have recommended the application of magnetic resonance imaging (MRI) and assessment of the stage of epiphyseal fusion in age estimation. This study involved retrospective MRI analysis of 335 cases (217 males and 118 females) whose ages ranged from 8 to 28 years (yrs). We assessed the degree of ossification of the proximal tibial epiphysis depending on the classifications of Schmeling and Kellinghaus used for the main stages (I, II, III, IV & V) and substages (IIa, b, c & IIIa, b, c). Significant differences between males and females at stages IIIc, IV and V (p < 0.001) were observed. Additionally, the ossification of the proximal tibial epiphyses occurred earlier in females than in males (2–4 yrs). The mean of ages in stage IV was approximately 18.6 yrs. in females and 22.5 yrs. in males, meaning that stage IV can be used as a valuable forensic marker to determine whether the person in question has reached the age of 18 yrs. We concluded that the application of MRI in the assessment of the ossification status of the proximal tibial epiphysis could be helpful in age estimation for various forensic purposes.     

Studies on the time frame for ossification of the medial clavicular epiphyseal cartilage in conventional radiography

Radiological assessment of the degree of ossification of the medial clavicular epiphyseal cartilage plays a vital part in forensic age diagnosis of living adolescents and young adults. A total of 873 plain chest radiographs requested by the staff medical officer for members of staff aged 16–30 at the University Hospital Charité were evaluated retrospectively. Of these X-rays 699 permitted an assessment of ossification of at least 1 side of the clavicle. In addition to the customary stages (1: non-ossified epiphysis, 2: discernible ossification centre, 3: partial fusion, 4: total fusion) a stage 5 was also defined, characterised by the disappearance of the epiphyseal scar following total fusion. The earliest age at which stage 3 was detected in either gender was 16 years. Stage 4 was first observed in women at 20 years and in men at 21 years. In both genders, the earliest observation of stage 5 was at 26 years. It was concluded that plain chest radiographs can essentially be used to assess clavicular ossification. In practice, if overlap in posterior-anterior views impedes evaluation, a lateral view should also be taken to facilitate age estimation. In forensic practice the reference values of the present paper should be applied.     

Bone age estimation based on multislice computed tomography study of the scapula

Progress in medical imaging has opened new areas of research in forensic anthropology, especially in the context of the study of bone age assessment. The study of bone age has become a useful tool for age estimation at death or age of young adult migrants in an anthropological context. We retrospectively evaluated multislice computed tomography (MSCT) explorations focused on scapulae of 232 individuals (123 males; 109 females) aged between 8 and 30 years old. Computed tomography (CT) scans were viewed in axial and multiplanar reconstructed images using OsiriX 5.9 (64 bit)®. The ossification centers of the scapula studied were as follows: acromial, sub-coracoid, glenoid, coracoid, coracoid apex, and inferior angle epiphyses. Fusion status was scored based on a five-stage system (stage 1: no ossification, stage 2: visualization of an ossification center, stage 3: partial ossification, stage 4: full ossification associated to an epiphyseal scar, and stage 5: full ossification without epiphyseal scar). Intra-observer variability was excellent, and inter-observer variability was good, demonstrating the reliability of this MSCT staging system. The fusion of scapular ossification centers was statistically associated with age (p < 0.001) but not with sex (p > 0.05). In conclusion, MSCT of the scapula is an efficient method for age assessment, which is complementary to preexisting methods particularly for specifying the 18-year threshold. Further studies with larger groups are needed to support our results.

     

手腕部桡尺骨骺线骨龄评价方法

目的:提出手腕部桡尺骨骺线骨龄评价方法。方法:研究样本为15~20岁的4359名(男1940名,女2419名)城市正常青少年。在受试者生日前后15日内拍摄左手腕正位X线片。将桡尺骨远端骺线消失过程划分为5个等级,以分类特征评分算法计算骺线等级得分,以Box-Cox幂指数分布模型拟合骺线成熟度得分百分位数曲线。结果:拟合曲线的百分位数与期望值差异大都小于3%,所拟合的百分位数曲线基本上反映了骺线成熟度得分的数据分布。结论:应用手腕部桡尺骨骺线指征将以往手腕部骨龄方法的评价范围扩展到了男20岁、女19岁。     

The persistence of epiphyseal scars in the adult tibia

Estimation of chronological age from skeletal material is dependent upon estimation of maturational stage observed. Following completion of epiphyseal fusion, a transverse radio-opaque line, termed “epiphyseal scar”, may be observed in the region of the former growth plate. According to the literature, this line is likely to become obliterated shortly after completion of epiphyseal fusion. Consequently, presence of an epiphyseal scar has been interpreted as an indication of recent epiphyseal fusion; however, this has not been validated by quantitative research. A study was undertaken to determine persistence of the epiphyseal scars in a cross-sectional population of adults between 20 and 50 years of age. This study examined 1,216 radiographs of proximal and distal tibiae from both sexes and sides of the body. This study suggested that 98.05 % of females and 97.74 % of males retained some remnant of the epiphyseal scar at the proximal tibia whilst 92.72 % of females and 92.95 % of males retained some remnant of the epiphyseal scar at the distal tibia. General linear model (GLM) analysis determined that chronological age accounted for 2.7 % and 7.6 % of variation in persistence of the epiphyseal scar at the proximal and distal tibiae, respectively. This study suggests that obliteration of the epiphyseal scar is not as dependent on chronological age as previously thought. It is, therefore, recommended that this feature not be used as an indicator of chronological age during forensic age assessment.     

Biometric sex assessment from the femur and tibia in a modern Greek population

Forensic anthropologists assess sex by analysing quantitative and qualitative characters of the human skeleton. In general, the pelvis and skull are the skeletal regions used most often, but in many cases, they are missing or fragmentary. In such circumstances, where only limb bones are present, it is necessary to use techniques based on other skeletal elements. Metric traits of the long bones of the lower extremities have been reported as reliable indicators of sex. This study was designed to determine whether the two main long bones of the leg, the femur and tibia, can be used for the assessment of sex on a Greek skeletal population. The skeletal sample used in this study comes from the modern human skeletal collection that is currently housed at the National and Kapodistrian University of Athens and is known as The Athens Collection. It consists of 371 femora and 372 tibiae corresponding to 200 adult individuals (111 males and 89 females). The age range is 19–96 years for males and 20–99 years for females. The maximum lengths and epiphyseal widths were measured for the present study, and it was found that the discriminant analysis of the metrical data of each long bone provided high sex discrimination accuracies. The rate of correct sex discrimination based on different long bones ranged from 91.50 % (left femur) to 93.40 % (left tibia). Our results suggest that lower limb bones can be used effectively for sexing in forensic contexts, in addition to other sex assessment techniques.