Does the Use of Sanders Staging and Distal Radius and Ulna Classification Avoid Mismatches in Growth Assessment with Risser Staging Alone?

BACKGROUND: Although Risser stages are visible on the same radiograph of the spine, Risser staging is criticized for its insensitivity in estimating the remaining growth potential and its weak correlation with curve progression in patients with adolescent idiopathic scoliosis. Risser staging is frequently accompanied by other skeletal maturity indices to increase its precision for assessing pubertal growth. However, it remains unknown whether there is any discrepancy between various maturity parameters and the extent of this discrepancy when these indices are used concurrently to assess pubertal growth landmarks, which are important for the timing of brace initiation and weaning. QUESTIONS/PURPOSES: (1) What is the chronologic order of skeletal maturity grades based on the growth rate and curve progression rate in patients with adolescent idiopathic scoliosis? (2) What are the discrepancies among the grades of each maturity index for indicating the peak growth and start of the growth plateau, and how do these indices correspond to each other? (3) What is the effectiveness of Risser staging, Sanders staging, and the distal radius and ulna classification in assessing peak growth and the beginning of the growth plateau? METHODS: Between 2014 and 2017, a total of 13,536 patients diagnosed with adolescent idiopathic scoliosis were treated at our tertiary clinic. Of those, 3864 patients with a radiograph of the left hand and wrist and a posteroanterior radiograph of the spine at the same visits including initial presentation were considered potentially eligible for this study. Minimum follow-up was defined as 6 months from the first visit, and the follow-up duration was defined as 2 years since initial consultation. In all, 48% (1867 of 3864) of patients were eligible, of which 26% (485 of 1867) were excluded because they were prescribed bracing at the first consultation. These patients visited the subsequent clinics wearing the brace, which might have affected body height measurement. Six percent (117 of 1867) of eligible patients were also excluded as their major coronal Cobb angle reached the surgical threshold of 50° and had undergone surgery before skeletal maturity. Another 21% (387 of 1867) of patients were lost before minimum follow-up or had incomplete data, leaving 47% (878) for analysis. These 878 patients with 1139 skeletal maturity assessments were studied; 74% (648 of 878) were girls. Standing body height was measured in a standardized manner by a wall-mounted stadiometer. Several surgeons measured curve magnitude as per routine clinical consultation, skeletal maturity was measured according to the distal radius and ulna classification, and two raters measured Risser and Sanders stages. Reliability tests were performed with satisfaction. Data were collected for the included patients at multiple points when skeletal maturity was assessed, and only up to when brace wear started for those who eventually had bracing. The growth rate and curve progression rate were calculated by the change of body height and major coronal Cobb angle over the number of months elapsed between the initial visit and next follow-up. At each skeletal maturity grading, we examined the growth rate (in centimeters per month) and curve progression rate (in degrees per month) since the skeletal maturity assessment, as well as the mean age at which this maturity grading occurred. Each patient was then individually assessed for whether he or she was experiencing peak growth and the beginning of growth plateau at each timepoint by comparing the calculated growth rate with the previously defined peak growth rate of ≥ 0.7 cm per month and the beginning of growth plateau rate of ≤ 0.15 cm per month in this adolescent idiopathic scoliosis population. Among the timepoints at which the peak growth and the beginning of growth plateau occurred, the median maturity grade of each maturity index was identified as the benchmark grade for comparison between indices. We used the McNemar test to investigate whether pubertal growth landmarks were identified by specific maturity grades concurrently. We assessed the effectiveness of these skeletal maturity indices by the difference in proportions (%) between two benchmark grades in indicating peak growth and the growth plateau. RESULTS: For girls, the chronological order of maturity grades that indicated peak growth was the radius grade, ulna grade, Sanders stage, and Risser stage. Curve progression peaked between the age of 11.6 and 12.1 years at a similar timing by all maturity indices for girls but was inconsistent for boys. For both sexes, radius (R) grade 6, ulna (U) grade 5, Sanders stage (SS) 3, and Risser stage 0+ were the median grades for peak growth, whereas Risser stage 4, R8/9, U7/8, and SS6/7 indicated the beginning of the growth plateau. The largest discrepancy between maturity indices was represented by Risser stage 0+, which corresponded to six grades of the Sanders staging system (SS2 to SS7) and to R6 in only 41% (62 of 152) of girls in the whole cohort. Despite Risser stage 0+ corresponding to the wide range of Sanders and distal radius and ulna grades, none of the R6, U5, SS3, and Risser stage 0+ was found more effective than another grade in indicating the peak growth in girls. R6 most effectively indicated the peak growth in boys, and Risser stage 0+ was the least effective. For the beginning of the growth plateau in girls, SS6/7 was the most effective indicator, followed by U7/8. Risser stage 4 was the least effective because it indicated 29% (95% CI 21% to 36%; p < 0.001) fewer patients who reached the beginning of the growth plateau than did those with R8/9. Risser stage 4 also indicated 36% (95% CI 28% to 43%; p < 0.001) fewer patients who reached the beginning of the growth plateau than those indicated by U7/8, and it identified 39% fewer patients than SS6/7 (95% CI 32% to 47%; p < 0.001). For boys, similarly, R8/9, U7/8, and SS6/7 were all more effective than Risser stage 4 in identifying when the growth plateau began. CONCLUSION: Risser stage 0+ corresponds to a wide range of Sanders and distal radius and ulna grades. Risser stage 0+ is least effective in indicating the peak growth in boys, and Risser stage 4 is the least effective maturity grade for indicating when the growth plateau starts in both sexes. The concurrent use of R6 and SS3 can be useful for detecting the peak growth, and SS6/7 in conjunction with U7/8 is most effective in indicating the beginning of the growth plateau. Using a combination of specific grades of Sanders staging and the distal radius and ulna classification can indicate pubertal growth landmarks with reduced risk of underestimating or overestimating skeletal maturity. These findings may aid in refining clinical decision-making of brace initiation and weaning at a more precise timing. Among Risser stage 0, the appearance of R6, U5, and SS3 provide the most effective assessment of peak growth that can indicate the most effective bracing period within which curve progression occurs. For initiation of the growth plateau, Risser 4 is not useful, and SS6/7, R8/9 and U7/8 should be used instead. LEVEL OF EVIDENCE: Level III, diagnostic study.

Forensic age assessment of asylum seekers in Finland.

In Finland, forensic age assessment is strictly regulated by legislation. According to the Aliens Act (301/2004) and the amendment of the Act (549/2010), the police authorities, the frontier guard authorities, and the immigration authorities have the right to refer asylum seekers to the University of Helsinki, Department of Forensic Medicine, for age assessment. These assessments are especially performed to solve if the person is of major age, the cutoff being 18 completed years. The forensic age assessment is largely based on dental development, since the special permit of the Radiation and Nuclear Safety Authority (STUK) to the Department of Forensic Medicine of the University of Helsinki, allowing the use of ionizing radiation for non-medical purposes, includes dental and hand X-rays. Forensic age assessment is always performed by two forensic odontologists. In 2015, the total number of forensic age assessment examinations was 149, and the countries of origin of the asylum seekers were most commonly Iraq, Afghanistan, and Somalia. The current legislation on forensic age assessment has been well received and approved. Radiological and other examinations can be performed in different parts of Finland, but the forensic odontologist at the University of Helsinki is always involved in the process and ensures joint quality standards for the forensic age assessment.

Contribution of magnetic resonance imaging of the wrist and hand to forensic age assessment.

Forensic age estimation of living individuals is a controversial subject because of the imprecision of the available methods which leads to errors. Moreover, young persons are exposed to radiation, without diagnostic or therapeutic advantage. Recently, non-invasive imaging techniques such as magnetic resonance imaging (MRI) have been studied in this context. The aim of this work was to study if the analysis of wrist/hand MRI enabled determination of whether a subject was 18 years old. Two observers retrospectively analyzed metaphyseal-epiphyseal fusion of the distal epiphysis of the radius and the ulna and the base of the first metacarpus in wrist/hand MRI of living people between 9 and 25 years of age. A three-stage scoring system was applied to all epiphyses. Intra- and inter-observer variability was excellent. Staging of the distal radial epiphysis allowed the subjects to be correctly evaluated with regard to the 18-year-old threshold in more than 85 % of cases. Analysis of the radius alone was as good as the analysis of the three epiphyses together. Evaluation of the metaphyseal-epiphyseal fusion of the distal radius in wrist MRI gave good results in forensic age estimation. Wrist MRI could meet ethical expectations with regard to the link between the benefit and risk of practicing radiologic examination on individuals in this context.

[Automated assessment of developmental levels of epiphysis by support vector machine].

OBJECTIVE: To realize the automated assessment of the levels of epiphysis of distal radius and ulna by support vector machine (SVM). METHODS: The X-ray films of the left wrist joints were taken from 140 teenagers aged from 11 to 19 years old as training samples. The levels of epiphysis of distal radius and ulna were divided into five developmental levels. Each level contained 28 samples. Another 35 cases were selected as independent verifying samples. SVM classification models of the five developmental levels of epiphysis of distal radius and ulna were established. The internal cross validation was made by leave one out cross validation (LOOCV), while the external validation was made by histogram of oriented gradient (HOG), and then the accuracy (PA) of testing results was calculated, respectively. RESULTS: The PA of SVM, LOOCV and HOG of distal radius epiphyseal level were 100%, 78.6%, and 82.8%, respectively; whereas the PA of SVM, LOOCV and HOG of distal ulna epiphyseal level were 100.0%, 80.0% and 88.6%, respectively. CONCLUSION: The SVM-based automatic models of the growth stage of distal ra- dius and ulna appear to have certain feasibility, and may provide a foundation for software development of bone age assessment by forensic medicine.

Assessment of bone response to conditioning exercise in the radius and tibia of young thoroughbred horses using pQCT.

OBJECTIVES: To assess the effect of conditioning exercise on bone parameters at multiple sites in the radius and tibia of young Thoroughbred horses. METHODS: The left and right radius and tibia were obtained from twelve horses, six of which had received conditioning exercise and six which formed the control group. Each bone was scanned at 5% intervals along its entire length using pQCT. RESULTS: Bone strength, bone area and periosteal circumference were significantly greater for the group of conditioned horses in both the radius and tibia. Volumetric bone mineral density was lower while bone mineral content, endocortical circumference and polar moment of inertia were higher in the conditioned group of horses but the significance of these differences varied between the two bones. Cortical thickness was not significantly different between the groups in either bone. CONCLUSIONS: Conditioning exercise stimulated a significant increase in the strength of both bones that could be attributed mainly to an increase in bone size, rather than differences in bone mineral content or density. The radius and tibia exhibited differences in the significance of changes in several bone parameters suggesting that not all bones respond in an identical fashion to imposed exercise.

The use of a computerized method of bone age assessment in clinical practice.

We assessed the reliability and repeatability of a new computerized bone age system, both versions 3.4 and 3.5 (licensed by Discerning System Inc. and Ares Service SA, Serono), able to automatically assess bone age on a left hand and wrist radiograph. This computer system is based upon Tanner and Whitehouse's method (TW2), but there are important differences. Our sample included an initial group of 40 patients who had growth delay/constitutional delay of growth and puberty (n = 10), growth hormone insufficiency/deficiency (n = 15), low birth weight/Silver-Russell syndrome (n = 9), precocious puberty (n = 6), as well as 20 patients with various skeletal dysplasias (multiple epiphyseal dysplasia n = 7, pseudoachondroplasia n = 7, acrodysostosis n = 5, achondroplasia n = 1), 7 girls with Turner syndrome, and 10 boys with nephrotic syndrome on chronic corticosteroid treatment. Multiple anthropometric readings of the same radiographs demonstrated excellent repeatability of the assessment. In addition, the number of times that a manual insertion of a grade was required was similar in four different assessments. The computerized method did not entirely avoid errors in interpretation as the position of the x-ray on the screen was critical. There was a high manual insertion rate in radiographs of children with skeletal dysplasia. However, the computer assessment system, version 3.5, performed adequately for radiographs of children with normal bone morphology and Turner syndrome and had the advantage of a continuous scale of assessment.