Dataset Information

In vivo testing of an injectable matrix gel for the treatment of shoulder cuff muscle fatty degeneration.

ABSTRACT:

Introduction

Extracellular matrix (ECM) gels have shown efficacy for the treatment of damaged tissues, most notably cardiac muscle. We hypothesized that the ECM gel prepared from skeletal muscle could be used as a treatment strategy for fatty shoulder cuff muscle degeneration.

Methods

We conducted experiments to (1) evaluate host biocompatibility to ECM gel injection using a rat model and (2) examine the effect of ECM gel injection on muscle recovery after delayed repair of a released supraspinatus (SSP) tendon using a rabbit model.

Results

The host biocompatibility to the ECM gel was characterized by a transient rise (first 2 weeks only) in several genes associated with macrophage infiltration, matrix deposition, and inflammatory cytokine production. By 8 weeks all genes had returned to baseline levels and no evidence of fibrosis or chronic inflammation was observed from histology. When gel injection was combined with SSP tendon repair, we observed a significant reduction (7%) in SSP muscle atrophy (24 + 3% reduction from uninjured) when compared with treatment with tendon repair only (31 + 7% reduction). Although fatty degeneration was elevated in both treatment groups, fat content trended lower (2%) in response to combined tendon repair and intramuscular ECM injection (4.1 + 2.1%) when compared with tendon repair only (6.1 + 2.9%). Transcriptome analysis revealed adipogenesis and osteoarthritis pathway activation in the repair only group. These key pathways were abrogated in response to treatment using combined repair plus gel.

Discussion

The findings suggest that ECM injection had a modest but positive effect on muscle mass, fatty degeneration, and key cellular signaling pathways.

SUBMITTER: Huynh T

PROVIDER: S-EPMC7669596 | biostudies-literature |

REPOSITORIES: biostudies-literature

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Project description:Background and hypothesisThe impact of preoperative fatty infiltration of specific rotator cuff muscles on the outcomes of reverse total shoulder arthroplasty (rTSA) has not been well defined. Preoperative fatty infiltration of the shoulder musculature will negatively affect rTSA outcomes.MethodsA comprehensive literature review was conducted as per the Preferred Reporting Items for Systematic Reviews and Meta-analyses using PubMed, Embase, OVID Medline, Scopus, Cinahl, Web of Science, and Cochrane databases for original, English-language studies evaluating effect of fatty infiltration of shoulder musculature on rTSA outcomes published from January 1, 2000 to present. Blinded reviewers conducted multiple screens. All included studies were graded based on the level of evidence, and data concerning patient demographics and postoperative outcomes were extracted.ResultsA total of 11 articles were included, including one level I article, three level III articles, and seven level IV articles. The review consisted of 720 patients and 731 shoulders (320 women and 157 men), with a mean age of 72.4 years. A single deltopectoral approach was performed for a majority of studies (627/731 shoulders), followed by a superolateral approach (70/731 shoulders) and a single transdeltoid approach (4/731 patients). Eleven studies reported data specifically about preoperative fatty infiltration of the rotator cuff musculature; the teres minor was studied most widely (298/731 shoulders), followed by the subscapularis (256/731 shoulders) and infraspinatus (232/731 shoulders). The Constant score (562/731 shoulders) and American Shoulder and Elbow Surgeons score (284/731 shoulders) were the most common recorded outcome scores. Fatty infiltration of the teres minor, supraspinatus, and infraspinatus was associated with worse range of motion after rTSA.ConclusionPreoperative fatty infiltration of the rotator cuff, particularly of the teres minor and infraspinatus, has a negative impact on subjective patient outcomes and restoration of range of motion, especially external rotation, after rTSA. The impact of fatty infiltration of the other rotator cuff muscles remains unclear, which may be due to intersurgeon differences in the handling of the remaining rotator cuff muscles or differences in implant design. The evaluated literature provides information on which patients can be educated about probable outcomes and restoration of function after rTSA.