Composition of Deltoid Muscle Fiber in Rotator Cuff Tear Condition

Received: 03-Mar-2022, Manuscript No. ijav-22-4559; Editor assigned: 06-Mar-2022, Pre QC No. ijav-22-4559(PQ); Reviewed: 11-Mar-2022 QC No. ijav-22-4559; Revised: 17-Mar-2022, Manuscript No. ijav-22-4559(R); Published: 25-Mar-2022, DOI: 10.37532/ijav.2022.15(3).188

Citation: Castellanos B. Composition of Deltoid Muscle Fiber in Rotator Cuff Tear Condition. Int J Anat Var. 2021;15(3):171-171.

This open-access article is distributed under the terms of the Creative Commons Attribution Non-Commercial License (CC BY-NC) (http://creativecommons.org/licenses/by-nc/4.0/), which permits reuse, distribution and reproduction of the article, provided that the original work is properly cited and the reuse is restricted to noncommercial purposes. For commercial reuse, contact reprints@pulsus.com

LETTER

The rotator cuff (RC) muscles coordinate shoulder movements and provide structural stability to the shoulder joint. 11The RC is prone to significant morbidity and RC tears are common, with a life prevalence of 10% to 20%. The supraspinatus (SS) muscle’s musculotendinous unit is especially prone to lesions4, but there is little information on the SS muscle’s pathophysiological response to traumatic tear conditions. However, the significance of RC muscle compositional and degenerative changes as causes of surgical failure has grown in recent years.

Skeletal muscle is made up of various fiber types that are distinguished by their specific myosin heavy chain (MHC) isoforms. Human skeletal muscles are primarily made up of MHC type 1 (slow twitch) and MHC type 2 (fast twitch) fibers. The functions of the two types differ. In humans, myosin ATPase hydrolysis rates for fast twitch fibers are 2-3 times higher than those for slow fibers26,36, and type 2 fibers have approximately 50% greater growth capacity than type 1 fibers. 1 Furthermore, type 1 fibers rely primarily on aerobic/oxidative energy metabolism, whereas type 2 fibers rely primarily on anaerobic/glycolytic metabolism [1].

No pathologic SS muscles in cadaveric 65-year-old (12-year) men and women were found to be composed of approximately 54% type 1 fibers,26 but physical activity and SS tendon tear may change the fiber-type composition. Individual training activity influences fiber-type composition, and muscle disuse or denervation may be associated with a type 1 to type 2 shift. 8,35 Age is also thought to influence muscle fibre composition, with older men having smaller type 2 muscle fibres than younger men,21 though other studies show no age-dependent difference in fibre type. 28,37 Gender appears to influence muscle fibre size, as type 2 muscle fibres are slightly larger than type 1 fibres in men, whereas the diameters of the two types of fibres are the same in women. Greater muscle strength in men is thought to be the cause of the genderdependent difference in thickness,20 and muscle strength is correlated with the size of type 2 muscle fibres. Several of these variables, including muscle fibre atrophy, muscle fibre loss, and lipid infiltration, are also important predictors of RC function [2].

As a result, a thorough examination of SS muscle composition and degree of atrophy could lead to a better understanding of the pathophysiology of muscle wasting/pathology in the context of RC tear. This is an essential tool in the development of therapeutic interventions for the healing of RC tears. The goal of this work was to use design-unbiased stereology to assess muscle fibre profiles of the SS muscle in tear situations.

In addition, fibre atrophy of the SS muscle was measured, and genderdependent variations in fiber-type composition were discovered.

This study included twenty-one patients (mean age, 60.3 4.0 years; range, 45- 73 years) who all had a lesion of one or more RC tendon rips involving the SS tendon [3].

Biopsies were obtained from the SS muscle in 14 males and 7 females who experienced an SS tendon injury. A blunt shaver was used to gently debride the SS muscle’s musculotendinous junction from fascia and bursal tissue. During arthroscopic RC tendon repair, twenty-one biopsies were collected roughly 1 cm medial to the tendon under direct view via the arthroscopy using a 3 mm biopsy punch through the lateral portal. In addition, 20 biopsies from presumed healthy, ipsilateral deltoid (DT) muscles were collected for comparison.

In addition, 20 biopsies from presumed healthy, ipsilateral deltoid (DT) muscles were collected for comparison. Shoulder trauma, a magnetic resonance imaging-confirmed RC lesion, and a willingness to undergo surgery were the inclusion criteria. At surgery, all tears were confirmed.

Severe tendon retraction, fatty infiltration greater than grade 2,14 diabetes, autoimmune illnesses, previous shoulder surgery, fractures, or a dislocated shoulder were all considered exclusion criteria [4].

All patients gave their informed written consent. The Danish Data Protection Agency was notified about the study. Histology, immunohistochemistry, and fibre typing. Biopsies were immersed in 10% phosphate-buffered formaldehyde, embedded in paraffin, and microtome sections were cut into 4-mm thick sections. Deparaffinized sections were deparaffinized, damasked in cell conditioning 1 (Roche Diagnostics, Hvidovre, Denmark) buffer, and blocked in hematoxylin and eosin (Roche Diagnostics, Hvidovre, Denmark) buffer for immune histo chemical labeling [5].

Acknowledgement

The author would like to acknowledge his Department of Anatomy from the University of Touro College of Osteopathic Medicine for their support during this work.

Conflicts of Interest

The author has no known conflicts of interested associated with this paper.

REFERENCES

1. Amy LH, Shari LM. Obtaining Meaningful Assessment in Thoracic Surgery Education . Thorac Surg Clin. 2019 Aug;29(3):239-247

Indexed at, Google Scholar, Crossref

2. Farid MS, Kristin W, Gilles B, et al. The History and Evolution of Surgical Instruments in Thoracic Surgery. Thorac Surg Clin.2021 Nov; 31 (4): 449- 461.

Indexed at, Google Scholar, Crossref

3. John C, Christian J. Commentary: Thoracic surgery residency: Not a spectator sport. J Thorac Cardiovasc Surg. 2020 Jun; 159(6):2345-2346.

Indexed at, Google Scholar, Crossref

4. Qi L , Xiaojie T, Yafang D, et al. Evaluation of Carotid Plaque Rupture and Neovascularization by Contrast-Enhanced Ultrasound Imaging: an Exploratory Study Based on Histopathology. Transl Stroke Res 2021 Feb; 12(1):49-56.

Indexed at, Google Scholar, Crossref

5. Kuo-Shyang J, Shu-Sheng L, Chiung-FC, et al. The Role of Endoglin in Hepatocellular Carcinoma. Int J Mol Sci 2021 Mar 22;22(6):3208

Indexed at, Google Scholar, Crossref