Hung Alec L H, Chau W W, Shi B, Chow Simon K, Yu Fiona Y P, Lam T P, Ng Bobby K W, Qiu Y, Cheng Jack C Y
1Department of Orthopaedics and Traumatology, The Chinese University of Hong Kong, Shatin, Hong Kong 2The Joint Scoliosis Research Centre of The Chinese University of Hong Kong and Nanjing University, Shatin, Hong Kong.
J Bone Joint Surg Am. 2017 Sep 6;99(17):1438-1446. doi: 10.2106/JBJS.16.01078.
Accurate skeletal maturity assessment is important to guide clinical evaluation of idiopathic scoliosis, but commonly used methods are inadequate or too complex for rapid clinical use. The objective of the study was to propose a new simplified staging method, called the thumb ossification composite index (TOCI), based on the ossification pattern of the 2 thumb epiphyses and the adductor sesamoid bone; to determine its accuracy in predicting skeletal maturation when compared with the Sanders simplified skeletal maturity system (SSMS); and to validate its interrater and intrarater reliability.
Hand radiographs of 125 girls, acquired when they were newly diagnosed with idiopathic scoliosis prior to menarche and during longitudinal follow-up until skeletal maturity (a minimum of 4 years), were scored with the TOCI and SSMS. These scores were compared with digital skeletal age (DSA) and radius, ulna, and small hand bones (RUS) scores; anthropometric data; peak height velocity; and growth-remaining profiles. Correlations were analyzed with the chi-square test, Spearman and Cramer V correlation methods, and receiver operating characteristic curve analysis. Reliability analysis using the intraclass correlation (ICC) was conducted.
Six hundred and forty-five hand radiographs (average, 5 of each girl) were scored. The TOCI staging system was highly correlated with the DSA and RUS scores (r = 0.93 and 0.92, p < 0.01). The mean peak height velocity (and standard deviation) was 7.43 ± 1.45 cm/yr and occurred at a mean age of 11.9 ± 0.86 years, with 70.1% and 51.4% of the subjects attaining their peak height velocity at TOCI stage 5 and SSMS stage 3, respectively. The 2 systems predicted peak height velocity with comparable accuracy, with a strong Cramer V association (0.526 and 0.466, respectively; p < 0.01) and similar sensitivity and specificity on receiver operating characteristic curve analysis. The mean age at menarche was 12.57 ± 1.12 years, with menarche occurring over several stages in both the TOCI and the SSMS. The growth remaining predicted by TOCI stage 8 matched well with that predicted by SSMS stage 7, with a mean of <2 cm/yr of growth potential over a mean of <1.7 years at these stages. The TOCI also demonstrated excellent reliability, with an overall ICC of >0.97.
The new proposed TOCI could provide a simplified staging system for the assessment of skeletal maturity of subjects with idiopathic scoliosis. The index needs to be subjected to further multicenter validation in different ethnic groups.
准确的骨骼成熟度评估对于指导特发性脊柱侧凸的临床评估很重要，但常用方法对于快速临床应用而言不够充分或过于复杂。本研究的目的是基于两个拇指骨骺和内收籽骨的骨化模式，提出一种新的简化分期方法，称为拇指骨化综合指数（TOCI）；与桑德斯简化骨骼成熟度系统（SSMS）相比，确定其在预测骨骼成熟方面的准确性；并验证其评分者间和评分者内的可靠性。
对125名女孩的手部X线片进行评分，这些X线片是在她们初潮前新诊断为特发性脊柱侧凸时以及纵向随访直至骨骼成熟（至少4年）期间获取的，采用TOCI和SSMS进行评分。将这些评分与数字骨骼年龄（DSA）、桡骨、尺骨和手部小骨（RUS）评分、人体测量数据、身高增长峰值速度以及剩余生长曲线进行比较。采用卡方检验、Spearman和Cramer V相关方法以及受试者工作特征曲线分析进行相关性分析。使用组内相关系数（ICC）进行可靠性分析。
共对645张手部X线片（平均每名女孩有5张）进行了评分。TOCI分期系统与DSA和RUS评分高度相关（r = 0.93和0.92，p < 0.01）。平均身高增长峰值速度（及标准差）为7.43 ± 1.45厘米/年，平均出现在11.9 ± 0.86岁，分别有70.1%和51.4%的受试者在TOCI第5期和SSMS第3期达到身高增长峰值速度。这两个系统预测身高增长峰值速度的准确性相当，Cramer V关联度较高（分别为0.526和0.466；p < 0.01），在受试者工作特征曲线分析中敏感性和特异性相似。初潮平均年龄为12.57 ± 1.12岁，在TOCI和SSMS中初潮均发生在多个阶段。TOCI第8期预测的剩余生长与SSMS第7期预测的剩余生长匹配良好，在这些阶段平均剩余生长潜力<2厘米/年，平均剩余生长时间<1.7年。TOCI还显示出出色的可靠性，总体ICC > 0.97。
新提出的TOCI可为特发性脊柱侧凸患者的骨骼成熟度评估提供一种简化的分期系统。该指数需要在不同种族群体中进行进一步的多中心验证。
