Abstract
Muscle atrophy has been established as a predictor of failure after rotator cuff repair. Traditionally, preoperative magnetic resonance imaging has been used as a baseline for subsequent comparison. Use of a preoperative baseline may overestimate the degree of atrophy present. In addition, postoperative progression of atrophy correlates with the integrity of the tendon.
Muscle atrophy associated with full-thickness rotator cuff tear has been associated with clinical outcome, functional recovery, and retear rates after repair.
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Generally, it is assumed that muscle atrophy is irreversible and may progress over time, even after repair.3
However, prior studies have used preoperative imaging as a baseline for comparison.1
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In the elegant study by Jo et al.,
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the authors examined the effect of arthroscopic rotator cuff repair on rotator cuff muscle atrophy at various time points including preoperatively, immediately postoperatively, and 1 year postoperatively. The complexity and cost of following up these patients with serial imaging is significant, and the authors are to be commended on the completion of this study.The results of the study suggest that, in general, rotator cuff muscle atrophy improves after arthroscopic repair but that increased atrophy is seen 1 year postoperatively as compared with the immediate postoperative state. Although these results may seem counterintuitive, they do correlate with the results of previous work that suggests that tendon and muscle retraction may account for the appearance of atrophy on preoperative imaging.
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In addition, they suggest that the use of preoperative imaging may overestimate the degree of atrophy and may be inappropriate to use as a comparison to assess subsequent changes. The authors correctly show that immediate postoperative imaging is a more appropriate baseline to be used for comparison against subsequent change.As would be expected, muscle atrophy did in fact worsen over time, but more so in the group with failed repair.
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The results of this study do highlight the importance of achieving structural integrity after rotator cuff repair in regard to functional recovery and prevention of progressive tear size and muscle deterioration over time.References
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- Changes of muscle atrophy according to the immediate postoperative time point in magnetic resonance imaging after arthroscopic rotator cuff repair.Arthroscopy. 2016; 32: 2477-2487
- Changes in appearance of fatty infiltration and muscle atrophy of rotator cuff muscles on magnetic resonance imaging after rotator cuff repair: Establishing new time-zero traits.Arthroscopy. 2013; 29: 449-458
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Footnotes
See related article on page 2477
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© 2016 by the Arthroscopy Association of North America
