Anatomy of Proximal Ulnar Angulations and Its Clinical Significance

Sağlam L., Nteli Chatzioglou G., Çandır B. N., Coşkun O., Gayretli Ö.

22. Ulusal Anatomi Kongresi , Ankara, Turkey, 13 - 17 October 2021

  • Publication Type: Conference Paper / Unpublished
  • City: Ankara
  • Country: Turkey
  • Istanbul University Affiliated: Yes


Objective: Because of the unique architecture and shape of the proximal ulna, particular difficulties exist for fixation and restoration for its fractures. The present study aimed to evaluate the proximal ulnar angulations anatomy that contributes to its different architecture.

Methods: After ethical approval was obtained from the Clinical Research Ethical Committee of Istanbul Faculty of Medicine (Date: 25/06/2021, number: 13), a sample of 107 adult ulnae that have no records of their age and sex was studied. A digital caliper was used to measure the ulnar length (UL), point of varus angulation (PVA), and widths at the point of varus angulation. The proximal ulnar angulations (proximal ulna torsion angle (PUTA), varus angulation (VA), articular angle (AA), proximal ulna dorsal angulation (PUDA), olecranon–diaphysis angle (ODA)) were determined with a goniometer. SPSS 21.0 (IBM Corporation, Armonk, NY, USA) was used for statistical analysis. In addition to descriptive statistics, Student t tests were used for comparison between two sides. Pearson correlation was calculated to evaluate relationships for parametric values whereas, Spearman’s correlation was used for non-parametric ones.

Results: The average UL was 261.17±43.06 mm, PVA was 82.27±10.65mm, total width was 15.04±1.83 mm, posterior-interosseus width was 13.71±2.36mm and posterior-anterior width was 15.15±1.92mm. The mean PUTA, VA, AA, PUDA and ODA were found 27.10 o±9.04o,13.61o±3.17o, 26.12o ±3.99o, 7.57o±3.80o and 17.39o±5.32o, respectively.  The VA was statistically significant differences between right and left (p < 0.05). A significant correlation was found between AA and ODA (p < 0.001).

Conclusion: The mean values of the angulations of proximal ulna can provide valuable data during surgery for the fixation of ulna. We believe that knowing these angulations may facilitate the intraoperative restoration of proximal ulna complex anatomy when dealing with comminuted or Monteggia fractures.

Keywords: Ulna; proximal ulnar angulations; fracture.