Adipocyte hyperplasia: the primary mechanism of supraspinatus intramuscular fat accumulation after a complete rotator cuff tendon tear: a study in the rabbit. (2nd January 2019)

• Record Type: Journal Article
• Authors: Trudel, Guy; Uhthoff, Hans K.; Wong, Kayleigh; Dupuis, Josée; Laneuville, Odette
• Is Part Of: Adipocyte. Volume 8:Number 1(2019)
• Page Start: 144
• Page End: 153
• Publication Date: 2019-01-02
• Subjects: Adipocytes -- fat clumps -- hyperplasia -- hypertrophy; Fat cells -- Periodicals; Adipocytes -- Periodicals; 611.018276
• DOI: 10.1080/21623945.2019.1609201
• Languages: English
• ISSNs: 2162-3945

Abstract

ABSTRACT: Intramuscular fat (IMF) accumulates in muscles of the rotator cuff after tendon tear. The number and cross-sectional area of fat clumps and of adipocytes were quantified on osmium tetroxide stained sections of the proximal, middle and distal quarters of SSP muscles 4, 8 and 12 weeks after SSP tendon division in a rabbit model. Linear mixed-effects models were fitted to the data and statistical significance was evaluated by ANOVA. Both the number (P<0.001) and cross-sectional area (P<0.0005) of fat clumps increased after tendon detachment while time had no significant effect (both at P>0.01). IMF accumulation was more important in the distal quarter of detached SSP muscle near tendon sectioning and characterized by increases of the number (P<0.0005) and cross-sectional area of fat clumps (P<0.0005) compared to the proximal quarter. Adipocyte number increased after tendon detachment (P<0.0005) and over time (P<0.01). The cross-sectional area of adipocytes increased in the detached group compared to controls (P<0.01) while time had no significant effect (P>0.01). Interestingly, the number of adipocytes in the distal quarter increased (P<0.0005) but the cross-sectional area was smaller (P<0.0005) compared to adipocytes in the proximal quarter. Adipocyte hyperplasia localized near tendon sectioning was the main contributor to fat accumulation in the detached SSP muscles.