# A detailed 3D volumetric magnetic resonance arthrographic analysis in a spiral ligament and anteroinferior capsuloligamentous complex of the shoulder joint

## TL;DR

This study uses 3D MR arthrography to analyze the anatomy and variations of specific shoulder ligaments in a large patient group.

## Contribution

The study provides new insights into the interrelationships and anatomical variations of the spiral and inferior glenohumeral ligaments.

## Key findings

- SpiGHL was identified in 7.9% of patients and often connected to the MGHL.
- MGHL hypoplasia was more common in patients with SpiGHL.
- A high insertion of AB-IGHL was found in 10.5% of patients and associated with younger age.

## Abstract

This study aimed to delineate the anatomical characteristics of the spiral glenohumeral ligament (SpiGHL), middle glenohumeral ligament (MGHL), and anterior band of inferior glenohumeral ligament (AB-IGHL), as well as their potential interrelationships, using MR arthrographic images from a large patient population.

All patients underwent 3D volumetric magnetic resonance (MR) arthrography sequences in addition to conventional MR imaging. All MR arthrography images were retrospectively assessed by two radiologists with expertise in arthrography. The origins and insertions of SpiGHL, MGHL, and AB-IGHL, along with any variations and interrelationships, were carefully examined and documented. These findings were statistically analyzed according to the patient’s age, gender, and laterality of the shoulder (right or left).

The study included 190 shoulder MR arthrographies, identifying SpiGHL in 15 patients (7.9%). Among the 190 patients, 20 (10.5%) had an AB-IGHL with a high insertion on the anterior glenoid margin. In 10 of 15 patients with SpiGHL (66.6%), a conjugation of SpiGHL and MGHL was observed. MGHL hypoplasia was observed in 11 MR arthrographies. Of the 11 patients, 5 (45.5%) also presented with SpiGHL. The incidence of SpiGHL was significantly higher in the group with hypoplastic MGHL. Additionally, the average age of patients with a high-origin AB-IGHL was significantly lower than that of patients without this feature.

Knowing the anterior capsuloligamentous detailed anatomy of the shoulder joint and its possible variations is important in correctly interpreting the pathologies of this region. The spiral GHL and its possible relationship with other ligaments can be defined in detail on MR arthrography.