# How to target the coronoid from the dorsal cortex

## TL;DR

This study provides a safe surgical method to target the coronoid process of the ulna from the dorsal cortex using measurements based on elbow anatomy.

## Contribution

The study introduces a practical, X-ray-free surgical targeting range for the coronoid process based on inter-epicondylar distance.

## Key findings

- Mean APEX was 20.6 mm and BASE was 33.9 mm, with significant gender differences.
- A safe targeting range is 2 to 3.5 cm from the olecranon's most prominent point.
- Ratios of APEX and BASE to IED were 0.3 and 0.6, respectively.

## Abstract

The coronoid process of the ulna is crucial for both anteroposterior and axial elbow stability. Currently, there is no safe and X-ray–free method for targeting the coronoid from the posterior cortex of the ulna, for temporary or permanent fixation. This study aims to define a range, easy to use in surgical practice, to safely target the coronoid process from the dorsal cortex of the ulna and to normalize the range based on the inter-epicondylar distance (IED).

For the study, 3 different parameters were assessed: the APEX (olecranon to coronoid apex distance), BASE (olecranon to coronoid base distance), and the IED from 109 computed tomographies.

The mean APEX was 20.6 mm (19.3 mm in females and 21.3 mm in males), and the mean BASE was 33.9 mm (31.9 mm in females and 35.1 mm in males). The mean IED was 59 mm (53.3 mm in females and 62.3 mm in males), the mean ratio between APEX and IED was 0.3 (0.4 in females and 0.3 in males), the mean ratio between BASE and IED was 0.6 (0.6 in males and females). These data were significantly different in males and females (P < .05).

This study contributes to establishing a practical range for the safe targeting of the coronoid process from the dorsal cortex of the ulna in surgical practice. A safe approach to the coronoid can be achieved by maintaining a perpendicular trajectory to the dorsal cortex of the olecranon within a safe range of 2 to 3.5 cm from its most prominent point.