Efficacy of Imaging Modalities Assessing Fatty Infiltration in Rotator Cuff Tears

Abstract

Background: Fatty atrophy is a diagnosis characterized by the combination of fatty infiltration and muscle atrophy of the rotator cuff. Studies have shown a strong positive correlation between the level of fatty infiltration and the risk of experiencing a chronic rotator cuff tear. Therefore, the purpose of the present study was to review the current literature on radiographic imaging of fatty infiltration and fatty atrophy to better aid surgeons in predicting functional outcome and to help guide patient decisions.Methods: We conducted a literature search in PubMed. The exact search queries included "rotator cuff" in the MeSH Terms field; "fatty atrophy," fatty infiltration," and "fatty muscle degeneration" in the Title/Abstract field; and various combinations of these searches. We initially found 184 articles using these keywords, including both human and animal studies. The 25 animal studies were excluded, leaving 159 articles. The abstracts of all remaining articles were reviewed and selected on the basis of our inclusion criteria of focusing on patients with rotator cuff tears (preoperatively and postoperatively), fatty infiltration, fatty atrophy, and imaging modalities. We excluded an additional 127 articles, leaving 32 articles that were selected for the final review and inclusion in this study.Results: Among 45 shoulder specialists across different studies, interrater agreement for Goutallier staging with use of magnetic resonance imaging (MRI) ranged from 0.24 to 0.82 and intrarater agreement for supraspinatus fatty changes ranged from 0.34 to 0.89. Our review also showed strong positive correlations when assessing the severity of fatty atrophy of the rotator cuff between MRI and ultrasound or ultrasound modalities such as sonoelastography.Conclusions: Increasing fatty infiltration of the rotator cuff is associated with greater repair failure rates and hence poorer overall clinical outcomes. MRI remains the gold standard for the imaging of rotator cuff tears and postoperative healing. Ultrasound can decrease health-care expenditures associated with the assessment of repair integrity postoperatively, although ultrasound is not as precise and has some limitations compared with MRI.Disclosure: There was no external funding source for the present study. On the Disclosure of Potential Conflicts of Interest forms, which are provided with the online version of the article, one or more of the authors checked "yes" to indicate that the author had a relevant financial relationship in the biomedical arena outside the submitted work (http://links.lww.com/JBJSREV/A443).

Surgical outcomes and complications following distal biceps tendon reconstruction: a systematic review and meta-analysis

“…Functional results may also be theoretically altered by fatty infiltration of the biceps muscle and restoration of postoperative muscle strength, which is also reflective of the time from injury to surgery, as has been demonstrated in other chronic tendon tears including those of the rotator cuff. 12 , 31 , 34 We had hypothesized that functional results would deteriorate and that complication rates would increase as a function of time between tendon injury and surgical reconstruction. In addition to the above-mentioned factors, this was also based on studies by Bisson et al 1 and Kelly et al, 16 which revealed an increased incidence, although not significant, in complication rates as the time between tendon injury and surgical repair increased.…”

Ultrasound Versus Magnetic Resonance Imaging as First-Line Imaging Strategies for Rotator Cuff Pathologies: A Comprehensive Analysis of Clinical Practices, Economic Efficiency, and Future Perspectives

“…While studies have demonstrated the high diagnostic value of high-frequency US, approaching comparability with MRI [ 14 ], US cannot match the precision of MRI in delineating individual muscle bulk loss. However, it can effectively identify and report on fatty replacement and overall atrophy of rotator cuff muscles, particularly when incorporating extended field of view (FOV) techniques [ 18 ].…”

“…Tenbrunsel et al asserted that MRI remains the gold standard for rotator cuff tear imaging and is a superior predictor of clinical outcomes. While US plays a role in reducing healthcare costs, its precision is somewhat compromised due to inherent limitations in comparison to MRI [ 18 ].…”

Fatty degeneration of the rotator cuff: pathogenesis, clinical implications, and future treatment

“… 50 , 79 , 87 In 2005, Strobel et al evaluated muscle pennate architecture and echogenicity of the supraspinatus (SSP) and infraspinatus (IS) using US and developed a three-point scale which has been used by other groups to confirm comparable US results to standard magnetic resonance imaging (MRI). 33 , 46 64 , 66 , 68 , 72 , 78 , 84 Despite promising results, drawbacks of US include the inability to distinguish moderate from severe fatty infiltration, problems with US wave penetrance in deep tissue and obese patients, and dependence on operator expertise. 33 , 39 , 67 …”

“… 16 , 25 Fuchs et al proposed a simplified 3-grade scale whose reliability compared to the traditional Goutallier scheme has been extensively studied and shown to be largely comparable but not necessarily better ( Table I ). 7 , 16 , 30 , 59 , 60 , 63 , 75 , 77 , 78 , 84 , 88 Additionally, radiographical rotator cuff atrophy signs such as the occupation ratio (SSP muscle surface area/SSP fossa surface area) and tangent sign (SSP does not intersect the line from the coracoid’s superior aspect to the superior border of the scapular spine on sagittal MRI) have been shown to correlate strongly with FDRC and may provide quick indications of muscle quality. 37 , 69 , 81 , 88 …”