A method to establish the relationship between chronological age and stage of union from radiographic assessment of epiphyseal fusion at the knee: an Irish population study

Abstract

Characteristic changes during epiphyseal union provide a skeletal age, which when compared with age-based standards provides an estimation of chronological age. Currently there are no data on epiphyseal union for the purposes of age estimation specific to an Irish population. This cross-sectional study aims to investigate the relationship between stage of epiphyseal union at the knee joint and chronological age in a modern Irish population. A novel radiographic method that sub-divides the continuum of development into five specific stages of union is presented. Anteroposterior and lateral knee radiographs of 148 males and 86 females, aged 9-19 years, were examined. Fusion was scored as Stage 0, non-union; Stage 1, beginning union; Stage 2, active union; Stage 3, recent union; or Stage 4, complete union. Stage of epiphyseal union is correlated with chronological age in both males and females. Mean age gradually increases with each stage of union and also varies between male and female subjects. A statistically significant difference in mean age was recorded between stages when compared to the previous stage, for the three epiphyses. Irish children are comparable to those from previously published studies with epiphyseal union in females occurring earlier than males. A significant difference was noted between the mean age of union for males and females for each of Stages 1 and 2 for the femur and Stages 0, 1, 2 and 3 for the tibia and the fibula. The results also suggest that the stages of union occur at earlier ages in this Irish population. Implementation of standardized methodology is necessary to investigate if this is due to a secular or population variation in maturation or to a methodology which clearly identifies five stages of union.

The persistence of epiphyseal scars in the distal radius in adult individuals

“…Despite the persistence of this feature being reported in multiple anatomical regions [25][26][27][28], the general consensus within the literature has been that following the completion of epiphyseal fusion, epiphyseal scars will become obliterated, resulting in a lack of distinction between the diaphysis and epiphysis when observed radiographically [5,16,17,28,29]. As a result of this perception, the transition between an observable epiphyseal scar and its disappearance has been incorporated into the staging criteria of several methods of age estimation [30][31][32]. There is however a paucity of published literature in relation to the potential persistence of the epiphyseal scar in this region.…”

Bone Age Determination of Epiphyseal Union Around Wrist Joint and its Correlation with Chronological Age: A Radiological Study in a Jordanian Population

“…Currently there is an obvious lack of standards for epiphyseal union for the purposes of assignment of chronological age 18 . Therefore, interpretation is likely to vary among investigators within different countries; this may be explained, however, on the basis of how the authors have classified their range of union 13 . It is generally accepted that there was no difference in the stage of union of the various epiphyses between right and left sides, which indicates that epiphyseal union appears to occur at the same time on both sides 13,19 .…”

“…This study has noted that there is generally a difference of two years between males and females, which is in agreement with the results of previously published studies, which have found that females typically develop union approximately two years in advance of males 16,20,24,25,34,35 . Therefore, it is clear that separate age range standards are required for males and females to ensure the greatest accuracy of age estimation 13 .…”

“…The long bones of upper and lower limbs play a vital role in assessment of age. The knee is an ideal anatomical locus for assessment of epiphyseal union, as the patient's knee joint often presents for investigation of trauma 13 . On the other hand, the hand-wrist region has received the greatest attention in assessment of skeletal maturation.…”

Radiological assessment of age from epiphyseal fusion at the knee joint

“…This should be apparent in at least one view on the radiograph, as a continuous radiolucent gap between the epiphysis and diaphysis. [14,15] Stage 1 -Beginning union: The epiphyseal and diaphyseal surfaces closely move towards each other. There is a narrow radiolucent strip between adjacent surfaces of the epiphysis and diaphysis when compared to the state of non-union.…”