Redefining the proximal ulna anatomy

Abstract

The unique bony architecture of the proximal ulna presents particular difficulties for the implants used in fracture fixation and arthroplasty of the elbow. Knowing the detailed anatomy of the variations of proximal ulna will guide the surgeon to obtain a more reliable length of the olecranon and to offer a safe place for Kirschner wire replacement concerning humero-ulnar joint functionality. In this study, PUTA was also defined. The angle determines the rotation of the proximal ulna and it has a great importance for the movements of the joint. The measured angulations will help the surgeon to design the proper prosthesis for the maintenance of the functions of the elbow joint.

Surgical Importance of Radiographically Aided Morphometry of the Proximal Ulna

“…The mean distance between the MPPO and MVA was 7.56 cm in the present study. Although the definitions of the most posterior point of the olecranon (MPPO) were varied in the literature, the results indicate close values Windisch et al, 2007,b;Beser et al;Totlis et al). While Wang et al (2003), and Grechenig et al were defined this morphometric length as distance between the triceps insertion and the point of varus angulation (MVA), the other authors defined this particular distance as in the present study.…”

“…However direct or indirect trauma causes fractures of the proximal ulna and affects the elbow joint movements (Windisch et al, 2007a). Displaced proximal ulnar fractures must be treated by stabilization implants that compatible the fracture pattern (Rouleau et al, 2010;Beser et al). The proximal ulnar morphometry should be considered in order to avoid misalignment, malunion, incompatibility of the elbow joint components, and abnormal rotational or flexion movements (Rouleau et al, 2010).…”

“…Also the different definitions may not truly be influential on the results. Proximal ulna shows unique structural angulations (varus and anterior angulations) and these angulations cause undeniable variations between individuals (Windisch et al, 2007b;Beser et al;Adikrishna et al, 2016). It is assumed that not only angulations of the morphometric features of the ulna influenced by demographic characteristics, but also and physical activities (repititive and force required actions) (Claussen, 1982).…”

“…However it has not been clear whether demographic characteristics or the variations affect the proximal ulnar pathologies. In addition, the discrepancy of values in the literature may vary by the different definition of the landmarks (Windisch et al, 2007b;Puchwein et al;Totlis et al;Beser et al;Adikrishna et al). For example; proximal ulna shows a gradual anterior deviation, starting from the middle and proximal one-third of the ulna and becomes more prominent proximally at the metaphysis (Siebenlist et al, 2019).…”

“…The displaced proximal ulna and the olecranon fractures are mostly stabilized by dorsal plates (Beser et al, 2014;George & Lawton, 2015;Melamed et al, 2015). The proximal and upper thirds of the ulnar fractures are surgically treated with open reduction and internal fixation In some cases if the fragments are not displaced, a simple splint immobilizing the forearm and preventing the elbow joint movements is adequate for rehabilitation (Brownhill et al, 2009).…”