Assessments of Fatty Infiltration and Muscle Atrophy From a Single Magnetic Resonance Image Slice Are Not Predictive of 3-Dimensional Measurements

Abstract

Purpose The purpose was to 1) determine whether standard clinical muscle fatty infiltration and atrophy assessment techniques using a single image slice for patients with a rotator cuff tear (RCT) are correlated with three-dimensional measures in older individuals (60+ years), and 2) determine whether age-associated changes to muscle morphology and strength are compounded by a RCT. Methods Twenty older subjects were studied, 10 with a RCT of the supraspinatus (5M/5F) and 10 matched controls. Clinical imaging assessments (Goutallier, Fuchs scores; cross-sectional area ratio) were made for RCT subjects. Three-dimensional measurements of rotator cuff muscle and fat tissues were made for all subjects using MRI. Isometric joint moment was measured at the shoulder. Results There were no significant associations between single-image assessments and three-dimensional measurements of fatty infiltration for supraspinatus and infraspinatus. Compared to controls, RCT subjects had significantly increased fatty infiltration percentages for each rotator cuff muscle (all p≤0.023), reduced whole muscle volume for supraspinatus, infraspinatus, and subscapularis (all p≤0.038), and reduced fat-free muscle volume for supraspinatus, infraspinatus, and subscapularis (all p≤0.027). Only teres minor (p=0.017) fatty infiltration volume was significantly greater for RCT subjects. Adduction, flexion, and external rotation strength (all p≤0.021) were significantly reduced for RCT subjects, and muscle volume was a significant predictor of strength for all comparisons. Conclusions Clinical scores using a single image slice do not represent three-dimensional muscle measurements. Efficient methods are needed to more effectively capture three-dimensional information for clinical applications. RCT subjects had increased fatty infiltration percentages likely driven by muscle atrophy rather than increased fat volume. Muscle volume’s significant association with strength production suggests that treatments to preserve muscle volume should be pursued for older RCT patients. Level of Evidence Level II, diagnostic study, with development of diagnostic criteria on the basis of consecutive patients with universally applied reference “gold” standard.

The effects of a rotator cuff tear on activities of daily living in older adults: A kinematic analysis

“…Efforts to avoid painful postures may expose the shoulder to impingement, particularly at more elevated postures (Ellenbecker and Cools, 2010). Alternatively, increased internal rotation may result from muscle force imbalance; strength assessments for these same RCT participants (Vidt et al, 2015) demonstrated markedly reduced external rotation strength. Force imbalances may affect glenohumeral loading characteristics, which can lead to further joint damage (Hsu et al, 2003) and other pathology, like humeral head translation.…”

A novel method for the quantification of fatty infiltration in skeletal muscle

“…However, histological sections are frequently only qualitatively evaluated (e.g., [31]) or scored on a rating scale to quantify differences between treatment groups (e.g., [29]) and, like CT and MRI techniques, are sampled from only one or a few places within the muscle volume (e.g., [32]). This limited sampling provides an incomplete picture of fatty infiltration in muscle as accumulation of adipocytes can be very spatially heterogeneous across the muscle volume [33]. Biochemical extraction of triglyceride from the skeletal muscle has been used extensively as a comprehensive and inexpensive quantification technique to study dynamic changes in intramyocellular lipid stores (e.g., [34]).…”

An age- and gender-related three-dimensional analysis of rotator cuff transverse force couple volume ratio in 304 shoulders

“…However, most of the studies do not take into account the quantification and analysis of the muscle volume. Recently, there has been controversy of three-dimensional measures and their predictor's role in the rotator cuff tear/pathology diagnosis and postoperative outcome [2,24]. Therefore, we suggest conducting research studies that evaluate the quantification and muscle volume ratio of the RCTFC in shoulders with musculotendinous pathology.…”

“…Previous studies have described the manual segmentation methodology as ''time consuming.'' Recently, Piepers et al [17] documented a mean time of 120 (90-160 min), and Tingart et al [22] a mean of 25 min to segment muscle mass making this methodology difficult to reproduce and apply to clinical practice [17,24]. The technique of oblique/multiplanar segmentation (Fig.…”

“…Rotator cuff muscle volume has been quantified by employing various imaging techniques in patients [6,11,12,17,23,24], cadavers [13,16,21,22], sheep [5] and primates [18,20]. Piepers et al [17] quantified the muscle volume correlation of the subscapularis muscle regarding the teres minor and infraspinatus in a series of 27 computed tomography scans in 21 patients, finding no significant differences among RCTFC components in healthy shoulders.…”