Muscle Architecture Properties of the Deep Region of the Supraspinatus: A Cadaveric Study.

Background: The supraspinatus is most frequently involved in rotator cuff tears, a common orthopaedic condition. However, the architecture of this muscle has been described only for the superficial, anterior, and posterior regions.

Purpose: To determine the muscle architecture of the deep supraspinatus.

Transcriptional time course after rotator cuff repair in 6 month old female rabbits.

Rotator cuff tears are prevalent in the population above the age of 60. The disease progression leads to muscle atrophy, fibrosis, and fatty infiltration, which is not improved upon with surgical repair, highlighting the need to better understand the underlying biology impairing more favorable outcomes. In this study, we collected supraspinatus muscle tissue from 6 month old female rabbits who had undergone unilateral tenotomy for 8 weeks at 1, 2, 4, or 8 weeks post-repair ( = 4/group).

Trochlear Lesion Caused by Suprapatellar Intramedullary Nailing and Treated with Autologous Chondrocytes Implant.

Introduction: Intramedullary nailing remains the most common method of treatment for tibial shaft fractures. The suprapatellar technique has proven to be useful in gaining and maintaining alignment, especially in proximal one-third tibia shaft fractures. It has been adopted by many surgeons taking trauma call, because it requires less set-up time and allows the surgery to be done with less assistance.

Articular cartilage delamination at eight years following cellular-based repair procedures: a case reports.

This report describes two cases of late cartilage delamination in two young adults after two different autologous cell-based techniques for cartilage restoration: 1. Matrix-assisted autologous chondrocyte implantation (MACI) and 2. Hyaluronic acid-bone marrow aspirate concentrate (HA-BMAC).

The "Second Hit" of Repair in a Rabbit Model of Chronic Rotator Cuff Tear.

The rabbit supraspinatus is a useful translational model for rotator cuff (RC) repair because it recapitulates muscle atrophy and fat accumulation observed in humans after a chronic tear (the "first hit"). However, a timeline of RC tissue response after repair, especially with regard to recent evidence of muscle degeneration and lack of regeneration, is currently unavailable. Thus, the purpose of this study was to characterize the progression of muscle and fat changes over time after the repair of a chronic RC tear in the rabbit model.

Corrigendum: Transcriptional Time Course After Rotator Cuff Tear.

[This corrects the article DOI: 10.3389/fphys.2021.

Supraspinatus muscle architecture and physiology in a rabbit model of tenotomy and repair.

Chronic rotator cuff tears can cause severe functional deficits. Addressing the chronic fatty and fibrotic muscle changes is of high clinical interest; however, the architectural and physiological consequences of chronic tear and repair are poorly characterized. We present a detailed architectural and physiological analysis of chronic tear and repair (both over 8 and 16 wk) compared with age-matched control rabbit supraspinatus (SSP) muscles.

Transcriptional Time Course After Rotator Cuff Tear.

Rotator cuff (RC) tears are prevalent in the population above the age of 60. The disease progression leads to muscle atrophy, fibrosis, and fatty infiltration in the chronic state, which is not improved with intervention or surgical repair. This highlights the need to better understand the underlying dysfunction in muscle after RC tendon tear.

Editorial Commentary: Cartilage Restoration-What Is Currently Available?

In the past 30 years, bone marrow stimulation techniques such as microfracture (MF) have become a popular method to treat symptomatic focal articular cartilage lesions. Nonetheless, recent studies have not shown good long-term clinical outcomes, and MF has produced alterations in the subchondral bone architecture with degenerative changes. Autologous chondrocyte implantation (ACI) has shown good results at 20 years.

Return to Work After Autologous Chondrocyte Implantation of the Knee in Patients with Workers Compensation Insurance.

Objective: This retrospective analysis aimed to evaluate patient and defect characteristics on return to work after autologous chondrocyte implantation (ACI) for all patients with workers compensation insurance in our clinic.

Methods: Retrospective analysis of medical records of patients with workers compensation treated with ACI in our clinic over 10 years (August 2004 to November 2014). Data were collected on demographics, lesion size and location, number of defects, duration of symptoms, and outcomes.

Rotator cuff tear state modulates self-renewal and differentiation capacity of human skeletal muscle progenitor cells.

Full thickness rotator cuff tendon (RCT) tears have long-term effects on RC muscle atrophy and fatty infiltration, with lasting damage even after surgical tendon repair. Skeletal muscle progenitor cells (SMPs) are critical for muscle repair in response to injury, but the inability of RC muscles to recover from chronic RCT tear indicates possible deficits in repair mechanisms. Here we investigated if muscle injury state was a crucial factor during human SMP expansion and differentiation ex vivo.

Cartilage Repair in the Inflamed Joint: Considerations for Biological Augmentation Toward Tissue Regeneration.

Cartilage repair/regeneration procedures (e.g., microfracture, autologous chondrocyte implantation [ACI]) typically result in a satisfactory outcome in selected patients.

Fresh osteochondral allografts in the knee: only a salvage procedure?

The role of fresh allogeneic osteochondral allograft transplantation (OCA) in the cartilage repair algorithm has been long debated and this procedure is primarily considered as a salvage procedure, to be used when other, simple, techniques have failed. Gracitelli et al. in a retrospective comparison of patients who received OCA as primary treatment or as a salvage procedure, demonstrates that the outcome of this procedure is minimally influenced by a previous failed treatment and that OCA represents an effective solution for both primary and revision surgery of chondral and osteochondral lesions of the knee.

The role of the peripheral and central nervous systems in rotator cuff disease.

Rotator cuff (RC) disease is an extremely common condition associated with shoulder pain, reduced functional capacities, and impaired quality of life. It primarily involves alterations in tendon health and mechanical properties that can ultimately lead to tendon failure. RC tendon tears induce progressive muscle changes that have a negative impact on surgical reparability of the RC tendons and clinical outcomes.

Epimuscular Fat in the Human Rotator Cuff Is a Novel Beige Depot.

Unlabelled: : Chronic rotator cuff (RC) tears are a common and debilitating injury, characterized by dramatic expansion of adipose tissue, muscle atrophy, and limited functional recovery. The role of adipose expansion in RC pathology is unknown; however, given the identified paracrine/endocrine regulation by other adipose depots, it likely affects tissue function outside its boundaries. Therefore, we characterized the epimuscular (EM) fat depot of the human rotator cuff, defined its response to RC tears, and evaluated its influence on myogenesis in vitro.

Muscle progenitor cell regenerative capacity in the torn rotator cuff.

Chronic rotator cuff (RC) tears affect a large portion of the population and result in substantial upper extremity impairment, shoulder weakness, pain, and limited range of motion. Regardless of surgical or conservative treatment, persistent atrophic muscle changes limit functional restoration and may contribute to surgical failure. We hypothesized that deficits in the skeletal muscle progenitor (SMP) cell pool could contribute to poor muscle recovery following tendon repair.

Effect of supraspinatus tendon injury on supraspinatus and infraspinatus muscle passive tension and associated biochemistry.

Background: Injury to the supraspinatus and infraspinatus tendons and the associated atrophic changes to the muscle remain a common clinical problem. Specifically, increased muscle stiffness has been implicated in failure of the repair and poor functional outcomes. We present a comparison of the passive mechanical properties and associated biochemical studies from patients with and without torn supraspinatus tendons.

Muscle gene expression patterns in human rotator cuff pathology.

Background: Rotator cuff pathology is a common source of shoulder pain with variable etiology and pathoanatomical characteristics. Pathological processes of fatty infiltration, muscle atrophy, and fibrosis have all been invoked as causes for poor outcomes after rotator cuff tear repair. The aims of this study were to measure the expression of key genes associated with adipogenesis, myogenesis, and fibrosis in human rotator cuff muscle after injury and to compare the expression among groups of patients with varied severities of rotator cuff pathology.

Use of platelet-rich plasma to enhance tendon function and cellularity.

Clinical studies have shown inconsistent healing with subjective improvement after use of platelet-rich plasma (PRP) for tendinosis and partial tendon tears. We conducted a study to assess changes after injecting PRP into an intact rabbit patellar tendon (PT) model. In the study group (n = 10), an incision was made over the PT and PRP was injected into multiple sites on the PT.

Can osteochondral grafting be augmented with microfracture in an extended-size lesion of articular cartilage?

Background: Both microfracture and osteochondral autografting procedures have been useful in treating osteochondral lesions.

Hypothesis: Combining microfracture and osteochondral autografting procedures can extend the size of lesions that can be treated with either technique.

Study Design: Descriptive laboratory study.

Follow-up of osteochondral plug transfers in a goat model: a 6-month study.

Background: Osteochondral transfer procedures are increasingly used to resurface full-thickness articular cartilage defects. There has not been long-term assessment/description of autogenous donor and recipient sites.

Hypothesis: The healing process occurs at the donor/host cartilage and bone interfaces.