Fatty Infiltration of the Torn Rotator Cuff Worsens Over Time in a Rabbit Model

      Purpose: The purpose of this investigation is to document quantitatively and qualitatively the changes that occur over time in the rotator cuff muscle after surgical detachment, simulating a chronic, unrepaired rotator cuff tear. Methods: The supraspinatus muscle was unilaterally detached from the greater tuberosity in 20 New Zealand white rabbits. All tendons were tagged and retracted from the insertion on the greater tuberosity. Five rabbits were killed at each designated time interval of 6 weeks, 3 months, 6 months, or 1 year after surgery. All animals underwent whole-body perfusion at the time of death for tissue preservation. Gross and histologic evaluations were performed to quantify the progression of fatty infiltration over time. Results: Loss of muscle and fatty infiltration were evident 6 weeks after detachment of the supraspinatus tendon. The fatty infiltration increased over time from 6 weeks to 1 year (P = .002, analysis of variance). The fatty infiltration was most pronounced near the supraspinatus insertion, and it progressed from the musculotendinous junction toward the muscle origin (Pearson correlation, r = −0.51; P < .0001). Conclusions: In this rabbit model of a surgically created rotator cuff tear, fatty infiltration is a progressive, infiltrative process that increases over time in the unrepaired rotator cuff. In addition, the muscle atrophy and fatty infiltration seen in rotator cuff tears progress from the musculotendinous junction toward the muscle origin. Clinical Relevance: This animal model of a chronic rotator cuff tear shows that fatty infiltration of the supraspinatus muscle appears as early as 6 weeks and worsens over time in the unrepaired rotator cuff. This may have implications on both the timing and management of rotator cuff tears.

      Key Words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to Arthroscopy
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Cancilla P.A.
        General reactions of muscle to injury. Churchill Livingstone, New York1984
        • Loehr J.F.
        • Mannion A.F.
        • Reichman H.
        • Gschwend N.
        Biomechanical changes of muscle in rotator cuff rupture. Vol 1. Elsevier, Paris1997
        • Coleman S.H.
        • Fealy S.
        • Ehteshami J.R.
        • et al.
        Chronic rotator cuff injury and repair model in sheep.
        J Bone Joint Surg Am. 2003; 85: 2391-2402
        • Björkenheim J.A.
        Structure and function of the rabbit’s supraspinatus muscle after resection of its tendon.
        Acta Orthop Scand. 1989; 60: 461-463
        • Fabis J.
        • Kordek P.
        • Bogucki A.
        • Mazanowska-Gajdowicz J.
        Function of the rabbit supraspinatus muscle after large detachment of its tendon: 6-week, 3-month, and 6-month observation.
        J Shoulder Elbow Surg. 2000; 9: 211-216
        • Nakagaki K.
        • Ozaki J.
        • Tomita Y.
        • Tamai S.
        Alterations in the supraspinatus muscle belly with rotator cuff tearing: Evaluation with magnetic resonance imaging.
        J Shoulder Elbow Surg. 1994; 3: 88-93
        • Goutallier D.
        • Postel J.M.
        • Bernageau J.
        • Lavau L.
        • Voison M.C.
        Fatty muscle degeneration in cuff ruptures.
        Clin Orthop Relat Res. 1994; : 78-83
        • Matsumoto F.
        • Uhthoff H.K.
        • Trudel G.
        • Loehr J.F.
        Delayed tendon reattachment does not reverse atrophy and fat accumulation of the supraspinatus—An experimental study in rabbits.
        J Orthop Res. 2002; 20: 357-363
        • Thomazeau H.
        • Boukobza E.
        • Morcet N.
        • Chaperon J.
        • Langlais F.
        Prediction of rotator cuff repair results by magnetic resonance imaging.
        Clin Orthop Relat Res. 1997; 344: 275-283
        • Shimuzo T.
        • Itoi E.
        • Minagawa H.
        • Pradhan R.L.
        • Wakabayashi I.
        • Sato K.
        Atrophy of the rotator cuff muscles and site of cuff tears.
        Acta Orthop Scand. 2002; 73: 40-43
        • Meyer D.C.
        • Hoppeler H.
        • von Rechenberg B.
        • Gerber C.
        A pathomechanical concept explains muscle loss and fatty muscular changes following surgical tendon release.
        J Orthop Res. 2004; 22: 1004-1007
        • McDowell E.M.
        • Trump B.M.
        Practical fixation techniques for light and electron microscopy.
        Comparative Pathology Bulletin. 1977; 9
        • Itoi F.
        • Hsu H.G.
        • Carmichael S.W.
        • Morrey B.F.
        • An K.N.
        Morphology of the torn rotator cuff.
        J Anat. 1995; 186: 429-434
        • Iannotti J.P.
        • Bernot M.P.
        • Kuhlman J.R.
        • Kelley M.J.
        • Williams G.R.
        Postoperative assessment of shoulder function: A prospective study of full-thickness rotator cuff tears.
        J Shoulder Elbow Surg. 1996; 5: 449-457
        • Burkhart S.B.
        • Esch J.C.
        • Jolson R.S.
        The rotator crescent and rotator cable: An anatomic description of the shoulder’s “suspension bridge.”.
        Arthroscopy. 1993; 9: 611-616