Metrical And Non-Metrical Study Of Lower End Of Ulna

The anatomic relationship between the distal radius and ulna and the carpus are precise; and even minor modifications in these relationships lead to significant load changes and resultant pain syndromes (viz. ulnar styloid impaction, uinocarpai abutment, Keinbock's disease). The articular circumference of the head of ulna is known as 'seat'. The distal aspect of the ulna consists of i) ulnar styloid process, ii) fovea and iii) pole. The distal radioulnar joint (DRUJ) allows excursions of forearm in supination and pronation; ulnar deviation of wrist enhances the manipulating skills of the hand. The differences in size, shape, inclination and area between the various compojnets of lower end of ulna will account for the dexterity or otherwise of movcements exhibited by the hand. A detailed metrical and nonmetrical study of lower end of ulna has been conducted on 129 dry fully ossified ulnae without any deformity and in 110 cadeveric ulnae. Styloid process showed great variations in its size and shape, being absent in 4.6% cases. The mean value of the maximum height of seat was 5.82 mm. Pole was projecting in 39.13% cases on right side and 31.66% on the left and was variable in shape-semilunar, semicircular, comma shaped and kidney shaped. The maximum width of fovea (along transverse axis) was 5.22 mm. Fovea showed the presence of a variable number of foramina.