# Association between rotator cuff muscle cross-sectional area and dorsal scapular artery blood flow velocity in patients with rotator cuff tears

## TL;DR

This study explores how rotator cuff muscle atrophy relates to blood flow in the dorsal scapular artery in patients with rotator cuff tears.

## Contribution

The study identifies a novel negative association between infraspinatus muscle atrophy and increased blood flow velocity in the dorsal scapular artery.

## Key findings

- Infraspinatus cross-sectional area at the glenoid face level negatively correlates with dorsal scapular artery peak systolic velocity.
- Other rotator cuff muscles showed no significant associations with hemodynamic changes.
- Findings suggest muscle atrophy may influence periscapular blood flow dynamics.

## Abstract

Atrophy of the rotator cuff (RC) muscles in the context of in patient's RC tears often results in humeral instability and scapular compensation, leading to symptoms like pain. Moreover, despite reports of increased in the peak systolic velocity (PSV) of the dorsal scapular artery (DSA) as a contributing factor, the specific relationship between RC atrophy and these hemodynamic changes has not been elucidated. This study aimed to quantitatively investigate the association between the cross-sectional area (CSA) of RC muscles and the PSV of the DSA.

Thirty-eight patients with RC tears were included. The CSA of the supraspinatus, infraspinatus (ISP), and subscapularis muscles were measured on T1-weighted magnetic resonance images at the glenoid face (GF) and scapular spine levels. The PSV of the DSA was assessed by Doppler ultrasonography. Statistical analyses were conducted using linear mixed models (LMM) and multiple regression analysis, adjusting for age and body mass index as covariates.

A significant negative interaction between ISP-CSA and PSV was observed at the GF level in the LMM (P = .03). Multiple regression analysis further indicated that only the ISP-CSA at the GF level exhibited a significant negative association with PSV (R2 = 0.23, P = .03). No significant associations were observed for other muscles. At the scapular spine level, neither LMM nor multiple regression analysis identified any significant interactions or effects.

These findings suggest that a decreased CSA of the ISP at the GF level is associated with increased PSV of the DSA, indicating that RC muscle atrophy may influence local hemodynamics in the periscapular region.