Moderate to severe fatty infiltration and rotator cuff atrophy are commonly associated with poor clinical outcomes and failed rotator cuff repair. Numerous animal and human studies have attempted to elucidate the etiology of fatty infiltration and rotator cuff atrophy. Mechanical detachment of the tendon in rotator cuff tears is primarily responsible. Suprascapular nerve injury may also play a role. CT, MRI, and ultrasonography are used to evaluate severity. The Goutallier staging system is most commonly used to evaluate fatty infiltration, and rotator cuff atrophy is measured using multiple techniques. The presence and severity of fatty infiltration have been associated with increasing age, tear size, degree of tendon retraction, number of tendons involved (ie, massive tears), suprascapular neuropathy, and traumatic tears. Fatty infiltration is irreversible and progressive if left untreated. Slight reversal of muscle atrophy has been noted after repair in some studies. Novel therapies are currently being evaluated that may eventually allow clinicians to alter the natural history and improve patient outcomes.
From Essentia Health, Duluth, MN (Dr. Kuzel), the Medical College of Wisconsin, Milwaukee, WI (Dr. Grindel), the Orthopaedic Associates of Wisconsin, Waukesha, WI (Dr. Papandrea), and Blount Orthopaedic Clinic, Milwaukee (Dr. Ziegler).
Dr. Grindel or an immediate family member serves as a board member, owner, officer, or committee member of the American Society for Surgery of the Hand, the Wisconsin Orthopaedic Society, and the Milwaukee Orthopaedic Society. Dr. Papandrea or an immediate family member is a member of a speakers' bureau or has made paid presentations on behalf of and serves as a paid consultant to Acumed and Exactech. Dr. Ziegler or an immediate family member serves as a paid consultant to DePuy. Neither Dr. Kuzel nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this article.