Preoperative IDEAL (Iterative Decomposition of Echoes of Asymmetrical Length) magnetic resonance imaging rotator cuff muscle fat fractions are associated with rotator cuff repair outcomes

Drew A Lansdown; Cyrus Morrison; Musa B Zaid; Rina Patel; Alan L Zhang; Christina R Allen; Brian T Feeley; C Benjamin Ma

doi:10.1016/j.jse.2019.05.018

Preoperative IDEAL (Iterative Decomposition of Echoes of Asymmetrical Length) magnetic resonance imaging rotator cuff muscle fat fractions are associated with rotator cuff repair outcomes

J Shoulder Elbow Surg. 2019 Oct;28(10):1936-1941. doi: 10.1016/j.jse.2019.05.018. Epub 2019 Jul 29.

Authors

Drew A Lansdown¹, Cyrus Morrison², Musa B Zaid², Rina Patel³, Alan L Zhang², Christina R Allen², Brian T Feeley², C Benjamin Ma²

Affiliations

¹ Department of Orthopedic Surgery, Sports Medicine & Shoulder Surgery, University of California, San Francisco, San Francisco, CA, USA. Electronic address: Drew.lansdown@ucsf.edu.
² Department of Orthopedic Surgery, Sports Medicine & Shoulder Surgery, University of California, San Francisco, San Francisco, CA, USA.
³ Department of Radiology & Biomedical Imaging, University of California, San Francisco, San Francisco, CA, USA.

PMID: 31371160
DOI: 10.1016/j.jse.2019.05.018

Abstract

Background and hypothesis: IDEAL (Iterative Decomposition of Echoes of Asymmetrical Length) imaging is a magnetic resonance imaging sequence that precisely measures rotator cuff muscle fatty infiltration. The influence of lower levels of fatty infiltration on outcomes after rotator cuff repair remains unclear. We hypothesized that increased preoperative fat fractions would be associated with inferior clinical outcomes after rotator cuff repair.

Methods: We retrospectively identified patients who underwent arthroscopic rotator cuff repair with preoperative IDEAL imaging. Patients completed the Patient-Reported Outcomes Measurement Information System (PROMIS) Upper Extremity computer adaptive survey at a minimum of 2 years after repair. Muscle segmentation was performed on 4 consecutive slices. Correlations between intramuscular fat fractions and PROMIS scores were determined. Patients were grouped by PROMIS scores of 50 or greater and scores lower than 50 for comparison of fat fractions. Multivariate linear regression was performed to model PROMIS scores as a function of demographic characteristics, tear size, and fat fractions. Significance was defined as P < .05.

Results: Eighty patients were included (mean follow-up, 42.5 ± 10.7 months). Postoperative PROMIS scores were significantly inversely correlated with the infraspinatus (ρ = -0.25, P = .02) and subscapularis (ρ = -0.29, P = .009) fat fractions. The infraspinatus (7.2% ± 4.9% vs. 5.2% ± 3.0%, P = .046) and subscapularis (10.4% ± 5.1% vs. 8.2% ± 5.0%, P = .001) fat fractions were significantly higher for patients with low PROMIS scores vs. those with PROMIS scores of 50 or greater. In multivariate modeling, the infraspinatus fat fraction (β = -0.68, P = .029) was the only significant independent predictor of postoperative PROMIS score.

Conclusion: Intramuscular fat as determined by quantitative magnetic resonance imaging is an important factor in postoperative outcomes even in patients with lower levels of preoperative fatty infiltration.

Keywords: IDEAL MRI; Rotator cuff repair outcomes; fatty infiltration; infraspinatus; muscle quality; quantitative imaging.

MeSH terms

Adipose Tissue / diagnostic imaging*
Adiposity*
Aged
Arthroscopy
Female
Humans
Magnetic Resonance Imaging*
Male
Middle Aged
Patient Reported Outcome Measures
Retrospective Studies
Rotator Cuff / diagnostic imaging*
Rotator Cuff Injuries / diagnostic imaging*
Rotator Cuff Injuries / surgery*
Treatment Outcome