An assessment of proximal ulna dorsal angulation using digital radiographic images

Background: The architecture of adult ulna is unique among long bones that have been described in the literature. But the best of our knowledge, the dorsal angulation of proximal ulna has not been described in detail. While using newer straight precontoured ulnar plates, the recognition of PUDA is important anatomic landmark for surgeons treating proximal ulna fractures, nonunions, malunions or osteotomies. The importance of this study was to characterize the proximal ulna dorsal angulation (PUDA) in patients with bilateral elbow radiographs. Materials & Methods: We examined bilateral elbow radiographs in 60 patients (30 male, 30 female), anteroposterior (AP) and lateral radiographs obtained. Measurements were recorded on each radiograph to identify the PUDA, later olecranon tip-to-apex distance of the PUDA was also measured. Results: The statistical analysis of measurements of PUDA had shown no significant differences between right and left elbow. PUDA was found in 92% of radiographs. The mean value of the tip-to-apex distance between men and women was significantly greater in men. Conclusion: Determination of the PUDA may be helpful in anatomic plating of the ulna for fractures, nonunions or malunions. Side to side correlation of PUDA measurements are reliable for recommendation to medical manufacturers for modelling ulna plates and components of artificial elbow joints.