McPherson E J, Friedman R J, An Y H, Chokesi R, Dooley R L
Department of Orthopedic Surgery, Medical University of South Carolina, Charleston 27425, USA.
J Shoulder Elbow Surg. 1997 Mar-Apr;6(2):105-12. doi: 10.1016/s1058-2746(97)90030-6.
Ninety-three cadaveric proximal humeri and matching scapulae with no evidence of shoulder disease were obtained. High-resolution roentgenograms were made. They were the digitized, and a custom computer program was used to obtain periosteal and endosteal dimensions (humeral canal width, shaft width, tuberosity offset, head offset, radius of curvature, head diameter, canal flare index, glenoid height and depth, arc of enclosure, radius of curvature, and depth of cancellous bone, among others). Statistical analyses included correlations among pairs of dimensions, regression analysis, and confidence intervals to estimate each geometric parameter. To represent the degree of conformity and constraint between the humeral head and glenoid, a conformity index (radius of head/radius glenoid) and constraint index (arc of enclosure/360) were calculated for each shoulder. Most of the parameters measured approximated a Gaussian distribution. Pairwise correlations of the geometric parameters showed that many were significantly associated at the 5% level (p < 0.05) with a high correlation coefficient (r > 0.4), meaning that the variations between the parameters were not purely random but rather they were related and that this relationship was useful in a predictive sense. With these key parameters identified, one can design components with an optimum fit or match an existing design to a patient's anatomy with a high degree of accuracy. No correlation was found between the radii of curvature for the humeral head and glenoid in either the coronal or sagittal plane or between the humeral head diameter and arc of enclosure. The mean conformity index was 0.72 in the coronal and 0.63 in the sagittal plane. Only 16% of the specimens had a conformity index greater than 0.9, indicating the radii of curvature matched. The vast majority had a more curved humeral head and flatter glenoid. Also, there was more constraint to the glenoid in the coronal versus sagittal plane (constraint index = 0.18 vs 0.13). These anatomic features help prevent superior-inferior translation of the humeral head but allow translation in the sagittal plane. This database of basic anatomic geometry defines the anatomic relationships of the proximal humerus and glenoid cavity that allow for a precise bone-implant fit and assesses the match between the shape of existing components and the patient's anatomy.
获取了93例无肩部疾病证据的尸体近端肱骨及匹配的肩胛骨。拍摄了高分辨率X线片。将其数字化后，使用定制的计算机程序获取骨膜和骨内膜尺寸（肱骨管宽度、骨干宽度、结节偏移、头部偏移、曲率半径、头部直径、管扩张指数、关节盂高度和深度、包绕弧、曲率半径以及松质骨深度等）。统计分析包括各尺寸对之间的相关性、回归分析以及用于估计每个几何参数的置信区间。为了表示肱骨头与关节盂之间的顺应程度和约束程度，为每个肩关节计算了顺应指数（头部半径/关节盂半径）和约束指数（包绕弧/360）。大多数测量参数近似高斯分布。几何参数的成对相关性表明，许多参数在5%水平（p < 0.05）具有显著相关性，相关系数较高（r > 0.4），这意味着参数之间的变化并非纯粹随机，而是相关的，并且这种关系在预测方面是有用的。确定这些关键参数后，就可以设计出拟合度最佳的组件，或者将现有设计与患者的解剖结构高度精确地匹配。在冠状面或矢状面中，肱骨头和关节盂的曲率半径之间以及肱骨头直径和包绕弧之间均未发现相关性。冠状面的平均顺应指数为0.72，矢状面为0.63。只有16%的标本顺应指数大于0.9，表明曲率半径匹配。绝大多数标本的肱骨头更弯曲，关节盂更平坦。此外，与矢状面相比，冠状面对关节盂的约束更大（约束指数 = 0.18对0.13）。这些解剖特征有助于防止肱骨头上下移位，但允许在矢状面内移位。这个基本解剖几何数据库定义了近端肱骨和关节盂腔的解剖关系，有助于实现精确的骨植入物匹配，并评估现有组件形状与患者解剖结构之间的匹配度。
