Impaired contractile function of the supraspinatus in the acute period following a rotator cuff tear
JournalBMC Musculoskeletal Disorders
PublisherBioMed Central Ltd.
MetadataShow full item record
AbstractBackground: Rotator cuff (RTC) tears are a common clinical problem resulting in adverse changes to the muscle, but there is limited information comparing histopathology to contractile function. This study assessed supraspinatus force and susceptibility to injury in the rat model of RTC tear, and compared these functional changes to histopathology of the muscle. Methods: Unilateral RTC tears were induced in male rats via tenotomy of the supraspinatus and infraspinatus. Maximal tetanic force and susceptibility to injury of the supraspinatus muscle were measured in vivo at day 2 and day 15 after tenotomy. Supraspinatus muscles were weighed and harvested for histologic analysis of the neuromuscular junction (NMJ), intramuscular lipid, and collagen. Results: Tenotomy resulted in eventual atrophy and weakness. Despite no loss in muscle mass at day 2 there was a 30% reduction in contractile force, and a decrease in NMJ continuity and size. Reduced force persisted at day 15, a time point when muscle atrophy was evident but NMJ morphology was restored. At day 15, torn muscles had decreased collagen-packing density and were also more susceptible to contraction-induced injury. Conclusion: Muscle size and histopathology are not direct indicators of overall RTC contractile health. Changes in NMJ morphology and collagen organization were associated with changes in contractile function and thus may play a role in response to injury. Although our findings are limited to the acute phase after a RTC tear, the most salient finding is that RTC tenotomy results in increased susceptibility to injury of the supraspinatus. Copyright 2017 The Author(s).
Identifier to cite or link to this itemhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85033599422&doi=10.1186%2fs12891-017-1789-5&partnerID=40&md5=0db895cd8400398489240f1b20282b06; http://hdl.handle.net/10713/11341
- Fatty Infiltration Is a Prognostic Marker of Muscle Function After Rotator Cuff Tear.
- Authors: Valencia AP, Lai JK, Iyer SR, Mistretta KL, Spangenburg EE, Davis DL, Lovering RM, Gilotra MN
- Issue date: 2018 Jul
- A method to test contractility of the supraspinatus muscle in mouse, rat, and rabbit.
- Authors: Valencia AP, Iyer SR, Pratt SJP, Gilotra MN, Lovering RM
- Issue date: 2016 Feb 1
- The effect of tear size and nerve injury on rotator cuff muscle fatty degeneration in a rodent animal model.
- Authors: Kim HM, Galatz LM, Lim C, Havlioglu N, Thomopoulos S
- Issue date: 2012 Jul
- Simvastatin reduces fibrosis and protects against muscle weakness after massive rotator cuff tear.
- Authors: Davis ME, Korn MA, Gumucio JP, Harning JA, Saripalli AL, Bedi A, Mendias CL
- Issue date: 2015 Feb
- Reduced muscle fiber force production and disrupted myofibril architecture in patients with chronic rotator cuff tears.
- Authors: Mendias CL, Roche SM, Harning JA, Davis ME, Lynch EB, Sibilsky Enselman ER, Jacobson JA, Claflin DR, Calve S, Bedi A
- Issue date: 2015 Jan