多股ACL移植物构建的几何拓扑：力学框架与探索性临床分析
简介
本研究建立ACL重建中2~6股腘绳肌腱移植物在股骨隧道内的几何拓扑框架，并回顾分析162例患者。结果显示偶数股（尤其4、6股）移植物对称性更佳、各向异性更低，且与较小的前向松弛及残余轴移相关。该发现提示移植物内部构型可能独立于直径影响术后稳定性，但尚需生物力学及体内测量进一步验证。
英文摘要
BACKGROUND: Hamstring graft preparation in anterior cruciate ligament (ACL) reconstruction varies widely, with strand number often determined by tendon length or surgeon preference. The influence of internal strand geometry on graft mechanical behaviour and postoperative stability remains poorly understood. METHODS: A geometric-mechanical framework was developed to characterize ACL graft constructs composed of two to six strands within a circular femoral tunnel. Spatial strand coordinates were used to derive four theoretical geometric descriptors: Symmetry Index (SI), effective polar moment of inertia (J_eff), Anisotropy Index (AI), and centroid displacement. Potential clinical relevance was explored in 162 patients undergoing primary ACL reconstruction with autologous hamstring grafts. Outcomes included anterior tibial translation, pivot-shift grade, and subjective IKDC score. Exploratory multivariable analyses adjusted for age, sex, pivoting sport participation, graft diameter, and follow-up duration. RESULTS: Even-strand constructs, particularly four- and six-strand grafts, demonstrated greater symmetry, higher polar moment of inertia, and lower anisotropy. Odd-strand constructs showed greater centroid displacement and geometric asymmetry. Exploratory clinical analyses showed numerical associations between greater theoretical geometric symmetry and lower anterior laxity and residual pivot shift. These descriptors represent theoretical structural properties rather than direct measurements of biomechanical performance. CONCLUSION: Internal graft topology may represent a structural characteristic influencing ACL graft behaviour beyond diameter alone. However, this hypothesis was not directly tested biomechanically or through in vivo topology measurements. The observed clinical associations are exploratory and hypothesis-generating. This geometric framework provides a conceptual basis for future biomechanical, computational, and clinical investigations of strand configuration. LEVEL OF EVIDENCE: III.