Substantial mismatch of skeletal maturity assessment between Risser sign and Simplified Skeletal Maturity Scale/Thumb Ossification Composite Index in patients with adolescent idiopathic scoliosis.

BACKGROUND: Recently, hand skeletal maturity systems such as the Simplified Skeletal Maturity Scale (SSMS) or Thumb Ossification Composite Index (TOCI) have been introduced to attempt to prospectively predict the occurrence of peak height velocity (PHV) in adolescents. This study aims to compare the frequency of the mismatch in estimation of HV between Risser sign (RS) and SSMS/TOCI stages in adolescent idiopathic scoliosis (AIS) patients. METHODS: One hundred thirty-three female patients with AIS were included. The mean age of the patients was 13.1 years. A whole spine and hand X-rays were obtained to establish skeletal maturity stage according to RS, SSMS, and TOCI systems. A mismatch resulting in overestimation (MOE) with RS compared to SSMS/TOCI was defined as the combination of RS 3-4/SSMS 3-5 or RS 3-4/TOCI 4-6, whereas a mismatch resulting in underestimation (MUE) with RS and SSMS/TOCI was defined as RS 0-1/SSMS 6-8 or RS 0-1/TOCI 7-8. Height velocity (HV) was compared between MOE/non-MOE and MUE/non-MUE groups. RESULTS: Between RS and SSMS, the rates of the MOE and MUE groups were 4.3% and 1.7%, respectively. Between RS and TOCI, rates were 2.8% and 1.7%, respectively. With the combination of RS and SSMS stages, an estimate of HV of 5.6 cm/year in the MOE group was significantly larger than that of 2.7 cm/year in the non-MOE group, and 3.7 cm/year in the MUE group was significantly smaller than 6.9 cm/year in the non-MUE group. Likewise, with the combination of RS and TOCI stages, an estimate of HV of 5.8 cm/year in the MOE group was significantly greater that of 2.7 cm/year in the non-MOE group, and 3.7 cm/year in the MUE group was significantly smaller than 6.9 cm/year in the non-MUE group. CONCLUSIONS: These findings support the use of SSMS/TOCI as the standard for assessing HV and skeletal maturity in patients with AIS.

A Simplified Skeletal Maturity Scale and Thumb Ossification Composite Index to Assess Skeletal Maturity and Predict Height Velocity in Japanese Females with Adolescent Idiopathic Scoliosis.

INTRODUCTION: Since Little et al. first reported that peak height velocity (PHV) could be described as a reliable clinical marker for the prediction of remaining growth and curve progression of adolescent idiopathic scoliosis (AIS) in clinical practice, much attention has been paid to PHV as a possible predictor of curve progression in patients with AIS. However, PHV itself is only identified retrospectively, so its value is not available at the first outpatient clinic visit. Using the simplified skeletal maturity scale (SSMS) and the thumb ossification composite index (TOCI) staging systems, this study aims to assess skeletal maturity and predict height velocity (HV) in Japanese female patients with AIS. METHODS: This study involved 95 female patients with AIS, ranging from 9 to 17 years old. A standing AP radiograph of the entire spine and a hand radiograph were retrospectively obtained to establish the skeletal maturity stage in accordance with the SSMS and TOCI systems. Height measurements were recorded at each visit; HV was calculated as the height change (cm) divided by the time interval (years). RESULTS: The TOCI stage rating increased identically to the SSMS stage rating increase. The chi-square test showed that there was a significant correlation between the two scoring systems (χ2=720.4). The Cramer V correlation also demonstrated a very strong correlation (Cramer V=0.62). Regarding the relationship between HV and each SSMS and TOCI stage, HV decreased as SSMS and TOCI stages increased. η 2 equaled to 0.67 in both groups and displayed a strong correlation between HV and SSMS and TOCI stages. CONCLUSIONS: These findings suggest that evaluation of the rate of HV using these radiological assessments is of supreme importance for determining the status of pubertal maturity and predicting the remaining amount of adolescent growth at the outpatient clinic visit.

[Contrastive study of thumb ossification composite index and Risser sign in evaluating the growth potential of adolescent idiopathic scoliosis].

Objective: To compare and analyze the correlations between thumb ossification composite index (TOCI), Risser sign and digital skeletal age (DSA) scores and to verify the possibility of TOCI as a supplementary to Risser sign in the evaluation of growth potential of adolescent idiopathic scoliosis (AIS) patients. Methods: Forty-nine AIS patients undergoing bracing treatment between May 2006 and May 2014 were selected from Nanjing Drum Tower Hospital. The follow-up interval was 4-6 months. The following data at each visit were routinely collected, including TOCI and DSA scores, as well as chronologic age and standing height. The height velocity (HV) at each visit was calculated based on the above data. All results were analyzed by Spearman correlation with TOCI and Risser sign. Results: There were strong correlations between TOCI and Risser sign and DSA scores (r=0.962, 0.813, both P<0.01). In AIS patients whose Risser sign were 0-1, the correlation between TOCI and DSA scores was more pronounced, compared with the correlation between Risser sign and DSA scores (0.918 vs 0.792, P<0.01). The HV averaged (7.1±2.1) cm/year in TOCI 5, significantly larger than these in other TOCI scores (all P<0.01). Conclusions: The TOCI 5 can be a sign of high height velocity and high growth potential in AIS patients. TOCI is a valid indicator of skeletal maturity evaluation and can be used as a helpful supplementary to Risser sign, whose predictive ability may be better than Risser sign.

Sequential spine-hand radiography for assessing skeletal maturity with low radiation EOS imaging system for bracing treatment recommendation in adolescent idiopathic scoliosis: a feasibility and validity study.

PURPOSE: The EOS-imaging system is increasingly adopted for clinical follow-up in scoliosis with the advantages of simultaneous biplanar imaging of the spine in an erect position. Skeletal maturity assessment using a hand radiograph is an essential adjunct to spinal radiography in scoliosis follow-up. This study aims at testing the feasibility and validity of a newly proposed EOS workflow with sequential spine-hand radiography for skeletal maturity assessment and bracing recommendation. METHODS: EOS spine-hand radiographs from patients with diagnosis of idiopathic scoliosis, including both sexes and an age range of ten to 14 years, were scored using the Thumb Ossification Composite Index (TOCI), Sanders and Risser methods. Intraclass correlation coefficients (ICCs) were calculated for inter/intraobserver agreement and were tested with Cronbach's alpha values. RESULTS: In all, 60 EOS-spine hand radiographs selected from subjects with diagnosis of adolescent idiopathic scoliosis (AIS), including 32 male patients (mean age 11.53 years; 10 to 14) and 28 female patients (mean age 11.50 years; 10 to 13) who underwent sequential spine-hand low dose EOS imaging were generated for analysis. The overall interobserver (ICC = 0.997) and intraobserver agreement (α > 0.9) demonstrated excellent agreement for TOCI staging; ICC > 0.994 for both TOCI and Sanders staging comparing traditional digital versus EOS hand radiography; ICC ≥ 0.841 for agreement on bracing recommendation among TOCI versus the Risser and Sanders system. CONCLUSION: With the proposed new EOS workflow it was feasible to produce high image quality for skeletal maturity assessment with excellent reliability and validity to inform consistent bracing recommendation in AIS. The workflow is applicable for busy daily clinic settings in tertiary scoliosis centres with reduced time cost, improved efficiency and throughput of the radiology department. LEVEL OF EVIDENCE: III.

[Value of thumb ossification composite index for predicting peripubertal growth potential in girls with adolescent idiopathic scoliosis].

Objective: To evaluate the predictive value of thumb ossification composite index (TOCI) for growth potential in female adolescent idiopathic scoliosis (AIS) patients and to analyze its correlation with several other indicators of growth potential. Methods: A retrospective review was conducted on 45 girls with AIS who underwent standard bracing treatment between October 2006 and August 2013 in Nanjing Drum Tower Hospital. All patients were regularly followed up with an interval of 3-6 months until brace weaning. At each visit, the following data were collected and recorded: chronologic age, stage of menses, standing height, Cobb angle of main curve, TOCI score, digital skeletal age (DSA) score and radius, ulna and small bones (RUS) score. The height velocity (HV) at each visit were calculated. The correlations analysis between TOCI and other indicators including DSA scores and RUS scores were studied. Results: The average age at initial visit was (10.9±1.3) years. The mean age of menarche was (12.6±1.3) years. The mean peak height velocity (PHV) was (7.5±1.5) cm/year and the mean age of PHV was (12.0±0.9) years. A total of 71.8% AIS girls attained their PHV at TOCI 5. The Spearman correlation analysis showed that TOCI was highly correlated with the DSA and RUS scores (r=0.95 and 0.96, both P<0.001). Chi-square test showed that TOCI 5 accurately predicted the occurrence of PHV (Cramer V=0.531, P=0.007). Conclusion: The TOCI 5 indicates high HV and high growth potential in AIS patients with bracing treatment. TOCI can thus serve as a good indicator for growth potential in braced AIS girls.

[Reliability and repeatability analysis of simplified skeletal maturity scoring and thumb ossification composite index in the assessment of skeletal maturity inadolescent idiopathic scoliosis].

Objective: To compare the reliability and repeatability of simplified skeletal maturity scoring (SSMS) and thumb ossification composite index (TOCI) in the assessment of skeletal maturity in adolescent idiopathic scoliosis(AIS) and their clinical utilization. Methods: A review was conducted on 500 AIS patients treated between October 2006 and August 2013 in Nanjing Drum Tower Hospital and one follow-up of each patient was randomly selected for this study.Based on SSMS and TOCI, the radiographs of the left palm were assessed by three observers independently with an interval of 2 weeks.The inter-observer reliability and intra-observer repeatability of two methods were analyzed by using Kappa value. Results: A total of 3 000 measurements were performed by the 3 surgeons for each method.For SSMS, 50 cases were described as stage 1 258 cases as stage 2 962 cases as stage 3 340 cases as stage 4 315 cases as stage 5 304 cases as stage 6 589 cases as stage 7 and 182 cases as stage 8.The inter-observer and intra-observer agreements was 76.8%-82.0% (Kappa value 0.716-0.778) and 75.8%-82.4% (Kappa value 0.705-0.782), respectively.For TOCI, 27 cases were described as stage 1 183 cases as stage 2 167 cases as stage 3 171 cases as stage 4 745 cases as stage 5 536 cases as stage 6 410 cases as stage 7 and 761 cases as stage 8.The inter-observer and intra-observer agreements was 91.6%-92.4% (Kappa value 0.897-0.907) and 90.4%-92.0%(Kappa value 0.882-0.902), respectively. Conclusions: The two methods of SSMS and TOCI have substantial inter-observer reliability and intra-observer reproducibility for the assessment of skeletal maturity in AIS.TOCI has relatively higher reliability and repeatability when compared with SSMS.