The morphometric parameters of the proximal radius of Chinese adults

Abstract

Objective To measure and study the morphometric parameters of the proximal radius, and to provide the references for further anatomical design of the radial head prosthesis. Methods The MRIs of 24 male and 24 female adult patients with lateral epicondylitis were reviewed. The following parameters were measured from the axial, sagittal, and coronal images: (1)maximum and minimum diameters of the radial head (Rmax and Rmin), (2) radial head height (H1), (3) radial neck height (Hn), (4) maximum and minimum intramedullary diameters at the narrowest level of the radial neck (Dmax and Dmin), and (5) depth of the radial head surface (Dep). Statistical analysis (SPSS16.0) was performed to analyze the relationship among individual morphometric data. Results The maximum radial head diameter (Pmax) and the minimum radial head diameter (Rmin) were (23.1±5.3) mm and (21.8±5.0) mm respectively. The radial head height (H1) and radial neck height (Hn) were (11.3±2.3) mm and (11.8±4.8) mm on average. The maximum intramedullary diameter at the narrowest level of the radial neck(Dmax)and the minimum intramedullary diameter at the narrowest level of the radial neck(Dmin)averaged (10.6±2.7)mm and (9.0±2.5) mm. The depth of the radial head surface was (2.1±0.6) mm on average.Rmax and Rmin of male were (25.1±4.2) mm and (23.7±4.0) mm respectively, H1and Hn(11.9±1.9) mm and (12.2±3.9) mm respectively, Dmax and Dmin (11.1±2.5) mm and (9.6±2.2) mm respectively. The depth of the articular surface was (2.2±0.6)mm. In female, Rmax and Rmin, were (21.1±2.3) mm and (19.9±2.2) mm respectively, H1 and Hn (10.7±1.9) mm and (11.5±6) mm respectively, Dmax and Dmin (10.0±2.6) mm and (8.4±2.3) mm respectively, and the depth of the articular surface was (2.0±0.6) mm. There were statistically significant differences between male and female radial head dimensions(P<0.05). Rmax and Rmin had a correlation of Rmin= 0.95 x Rmax; and there was a correlation between Dmax and Dmin with the formula Dmin=0.85×Dmax(P<0.05). The correlations between Rmax and Dmax, Rmax and H1, Rmax and Hn were more dispersed. Conclusion The radial head has an ellipse shape. The commercially available radial head prostheses can not precisely replicate normal anatomy.Modular implant system slmuld be considered. Key words: Radius; Prosthesis; Research design; Nuclear magnetic resonance