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

Is there a skeletal age index that can predict accurate curve progression in adolescent idiopathic scoliosis? A systematic review

BACKGROUND

The diagnosis of adolescent idiopathic scoliosis requires clinical and radiographic evaluation; the management options vary depending on the severity of the curve and potential for progression. Identifying predictors of scoliosis progression is crucial to avoid incorrect management; clinical and radiographic factors have been studied as potential predictors. The present study aims to review the literature on radiological indexes for the peak height velocity or curve acceleration phase to help clinicians manage treatment of patients with adolescent idiopathic scoliosis.

METHODS

This systematic review was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The search was carried out including only peer-reviewed articles written in English that described the radiological indexes assessing skeletal maturity in patients with adolescent idiopathic scoliosis and evaluated their correlation with curve progression, expressed as peak height velocity and/or curve acceleartion phase.

RESULTS

Thirteen studies were included and showed promising results in terms of reliable radiological indexes. Risser staging gives a general measure of skeletal maturity, but it cannot be used as a primary index for driving the treatment of patients with adolescent idiopathic scoliosis since more reliable indexes are available.

CONCLUSION

Skeletal maturity quantification for adolescent idiopathic scoliosis has the potential to significantly modify disease management. However, idiopathic scoliosis is a complex and multifactorial disease: therefore, it is unlikely that a single index will ever be sufficient to predict its evolution. Therefore, as more adolescent idiopathic scoliosis progression-associated indexes are identified, a collective scientific effort should be made to develop a therapeutic strategy based on reliable and reproducible algorithms.

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.

The Interrater and Intrarater Reliability of the Humeral Head Ossification System and the Proximal Femur Maturity Index Assessments for Patients with Adolescent Idiopathic Scoliosis

Background

Skeletal maturity can evaluate the growth and development potential of children and provide a guide for the management of adolescent idiopathic scoliosis (AIS). Recent studies have demonstrated the advantages of the Humeral Head Ossification System (HHOS) and the Proximal Femur Maturity Index (PFMI), based on standard scoliosis films, in the management of AIS patients. We further assessed the HHOS and the PFMI method's reliability in the interrater and intrarater.

Methods

The data from 38 patients, including the humeral head and proximal femur on standard scoliosis films, were distributed to the eight raters in the form of a PowerPoint presentation. On 38 independent standard spine radiographs, raters utilized the HHOS and PFMI to assign grades. The PPT sequence was randomly changed and then reevaluated 2 weeks later. For every system, the 95% confidence interval (95% CI) and intraclass correlation coefficient (ICC) were calculated to evaluate the interrater and intrarater reliability.

Results

The HHOS was extremely reliable, with an intraobserver ICC of 0.802. In the first round, the interobserver ICC reliability for the HHOS was 0.955 (0.929-0.974), while in the second round, it was 0.939 (0.905-0.964). The PFMI was extremely reliable, with an intraobserver ICC of 0.888. In the first round, the interobserver ICC reliability for the PFMI was 0.967 (0.948-0.981), while in the second round, it was 0.973 (0.957-0.984).

Conclusions

The HHOS and PFMI classifications had excellent reliability. These two methods are beneficial to reduce additional exposure to radiation and expense for AIS. There are advantages and disadvantages to each classification. Clinicians should choose a personalized and reasonable method to assess skeletal maturity, which will assist in the management of adolescent scoliosis patients.