Results of the Between Groups Principal Components Analysis (BgPCA) based on patellar measurements.

Abbreviations: bgPC, between-group principal component; PD, total proximodistal height of the patella; PDAS, proximodistal height of the articular surface; AP, anteroposterior thickness; ML, mediolateral breadth. a Each original variable was size-adjusted by the geometric mean (GM) of the four variables and log-transformed (using natural logarithms) prior incorporation into the analysis. The variables with absolute loadings of 0.5 or more are marked in bold. Only the two first bgPC axes provided meaningful discrimination and are therefore shown.缩写说明：bgPC（between-group principal component，组间主成分）；PD（total proximodistal height of the patella，髌骨总近远高度）；PDAS（proximodistal height of the articular surface，关节面近远高度）；AP（anteroposterior thickness，前后径厚度）；ML（mediolateral breadth，内外径宽度）。① 所有原始变量在纳入分析前，均通过4个变量的几何均值（geometric mean, GM）进行尺寸校正，并经自然对数转换。载荷绝对值≥0.5的变量以粗体标注。仅前两组间主成分（bgPC）轴具备有效的区分能力，故仅展示该两类轴。