ABSTRACT
Objectives : This study aimed to evaluate the diagnostic validity of assigned estimations between identified
points on the upper end of the ulna using radiological films of the forearm obtained in midprone position.
Materials & Methods: The study included 60 healthy adult volunteers; 30 males and 30 females within an
age range of 30-35 years. Right upper limb was photographed in resting midprone position to obtain a lateral
view of the upper limb extending from the mid-humoral shaft till the head of metacarpal bones including elbow
and wrist joints. The olecraizon-coronoid angle (OCA) was defined as an imaginary angle formed by a line
extended from the most prominent point of the upper end of ulna to the root of the styloid process (Line 1) and
another extended between the most prominent points of the anterior borders of the coronoid and olecranon
processes (Line 2). Line-3 was perpendicular on line-1 dropped from the tip of the coronoid process to represent
the coronoid process height (CH). Line-4 extended from the top point of coronoid process till the deepest point of
the trochkar notch to identifij its depth (ND). Receiver Operating Characteristic (ROC) curve analysis judged
by the Area Under Curve (AUC) and Loges tic Regression multivariate analysis (Stepwise Method) were used to
verifij the obtained results.
Results: Masculine measurements were significantly higher compared to feminine measurements. Using ROC
curve analysis, the three measures showed high specificity for identification of masculine ulnae with significance
difiirence compared to the null hypothesis that true ALIC=0.5. Regression analysis defined the OCA
measurements and CH length cc the most valuable measures for sex discrimination irrespective of the cutoff
point. The total diagnostic yield of the three measurements could idenhfij masculine ulnae with sensitivity rate
of 88.9%, specificity rate of 95.5% and accuracy rate of 92.2%.
Conclusion : The utility of proximal Ulnar end measurements for sex discrimination provided an accuracy
rate of 92.2% and the combined estimation of OCA and coronoid process height provided significant
discriminative power and both are recommended as measures for sex identification. '1 |
