Department of Orthopaedics and Traumatology, University of Hong Kong, Hong Kong SAR, China.
Bone Joint J. 2021 Jan;103-B(1):141-147. doi: 10.1302/0301-620X.103B1.BJJ-2020-1240.R1.
The aim of this study was to investigate whether including the stages of ulnar physeal closure in Sanders stage 7 aids in a more accurate assessment for brace weaning in patients with adolescent idiopathic scoliosis (AIS).
This was a retrospective analysis of patients who were weaned from their brace and reviewed between June 2016 and December 2018. Patients who weaned from their brace at Risser stage ≥ 4, had static standing height and arm span for at least six months, and were ≥ two years post-menarche were included. Skeletal maturity at weaning was assessed using Sanders staging with stage 7 subclassified into 7a, in which all phalangeal physes are fused and only the distal radial physis is open, with narrowing of the medial physeal plate of the distal ulna, and 7b, in which fusion of > 50% of the medial growth plate of distal ulna exists, as well as the distal radius and ulna (DRU) classification, an established skeletal maturity index which assesses skeletal maturation using finer stages of the distal radial and ulnar physes, from open to complete fusion. The grade of maturity at the time of weaning and any progression of the curve were analyzed using Fisher's exact test, with Cramer's V, and Goodman and Kruskal's tau.
We studied a total of 179 patients with AIS, of whom 149 (83.2%) were female. Their mean age was 14.8 years (SD 1.1) and the mean Cobb angle was 34.6° (SD 7.7°) at the time of weaning. The mean follow-up was 3.4 years (SD 1.8). At six months after weaning, the rates of progression of the curve for patients weaning at Sanders stage 7a and 7b were 11.4% and 0%, respectively for those with curves of < 40°. Similarly, the rates of progression of the curve for those being weaned at ulnar grade 7 and 8 using the DRU classification were 13.5% and 0%, respectively. The use of Sanders stages 6, 7a, 7b, and 8 for the assessment of maturity at the time of weaning were strongly and significantly associated (Cramer's V 0.326; p = 0.016) with whether the curve progressed at six months after weaning. Weaning at Sanders stage 7 with subclassification allowed 10.6% reduction of error in predicting the progression of the curve.
The use of Sanders stages 7a and 7b allows the accurate assessment of skeletal maturity for guiding brace weaning in patients with AIS. Weaning at Sanders stage 7b, or at ulnar grade 8 with the DRU classification, is more appropriate as the curve did not progress in any patient with a curve of < 40° immediately post-weaning. Thus, reaching full fusion in both distal radial and ulnar physes (as at Sanders stage 8) is not necessary and this allows weaning from a brace to be initiated about nine months earlier. Cite this article: 2021;103-B(1):141-147.
本研究旨在探讨 Sanders 7 期中尺骨骺闭合阶段的纳入是否有助于更准确地评估青少年特发性脊柱侧凸（AIS）患者支具的脱支情况。
这是一项对 2016 年 6 月至 2018 年 12 月期间脱支的患者进行的回顾性分析。纳入标准为：Risser 分期≥4 岁、静态站立身高和臂展至少 6 个月、初潮后至少 2 年。脱支时的骨骼成熟度采用 Sanders 分期评估，7 期分为 7a 期，所有指骨骺均融合，仅桡骨远端骺开放，尺骨远端干骺端内侧骺板变窄，以及 7b 期，尺骨远端骺板存在>50%的融合，以及桡尺骨（DRU）分类，这是一种成熟度评估指数，使用桡骨和尺骨远端骺的更精细阶段（从开放到完全融合）来评估骨骼成熟度。采用 Fisher 精确检验、Cramer's V、Goodman 和 Kruskal tau 分析脱支时的成熟度等级和曲线进展情况。
我们共研究了 179 例 AIS 患者，其中 149 例（83.2%）为女性。患者平均年龄为 14.8 岁（标准差 1.1），脱支时平均 Cobb 角为 34.6°（标准差 7.7°）。平均随访时间为 3.4 年（标准差 1.8）。脱支后 6 个月，Sanders 7a 期和 7b 期患者的曲线进展率分别为<40°患者的 11.4%和 0%。同样，DRU 分类中尺骨 grade 7 和 8 的脱支率分别为 13.5%和 0%。Sanders 6、7a、7b 和 8 期用于评估脱支时的成熟度与脱支后 6 个月曲线进展有很强的显著相关性（Cramer's V 0.326；p=0.016）。
Sanders 7a 和 7b 期的使用可以准确评估骨骼成熟度，指导 AIS 患者的支具脱支。Sanders 7b 期或 DRU 分类中的尺骨 grade 8 期脱支时，<40°的患者在脱支后即刻无曲线进展，因此更合适。因此，不必等到桡骨和尺骨远端骺完全融合（如 Sanders 8 期），这可以使支具脱支提前约 9 个月开始。
