Tendon healing begins with inflammation and results in an incomplete repair with fibrosis, culminating in tendon pathology along with tissue degeneration. Inflammatory mediators regulate the expression of growth factors, and members of the TGFβ superfamily including BMPs have been suggested to play a key role in the development of fibrosis. In established tendon diseases where inflammation and reparative processes persists, the cellular phenotype of tendon cells has been implied to undergo a transformation from that of normal tissue. This study investigates the inflammation-driven mechanisms of tendon pathology using an Diseased human tendon cells were isolated from patients with large to massive rotator cuff tears (n=4). Cells isolated from healthy human hamstring tendons served as control tissue (n=5). Cells were treated with human recombinant IL-1β (5ng/ml), oncostatin M (10ng/ml), IL-6 (10ng/ml), IL-10 (10ng/ml) in serum-free medium, or serum-free medium alone (control) for 24 hours. Cell viability was monitored by Alamar Blue assay, and expression of Introduction
Materials and Methods
Dickkopf-3 is upregulated in OA cartilage and synovial tissue. In vitro studies show Dkk3 can prevent cartilage degradation and antagonise Wnt signaling. We hypothesis that Dkk3 can protect against OA-related cartilage destruction. Our group has previously shown that Dkk3, a member of the Dkk family of Wnt antagonists, is upregulated in OA cartilage and synovium. Levels of Dkk3 in synovial fluid are also increased in individuals with tricompartmental OA and after arthroscopy. The role of Dkk3 in cartilage or the factors regulating its expression are not currently understood. Correct regulation of cell signalling pathways is integral to cartilage homeostasis and thus the prevention of OA pathogenesis. Dkk3 is a member of the Dkk family of Wnt antagonists and therefore may impact on chondrocyte biology through interaction with the Wnt pathway. Dkk3 has also been found to influence TGFβ signalling in other cell systems.Summary Statement
Introduction
The effects of local glucocorticoid on tendon appear broadly negative and this supports the emerging clinical evidence which points toward significant long term harms associated with this treatment modality. The use of locally administered glucocorticoid is widespread in the treatment of painful tendinopathy. Despite evidence of short term benefit, the emerging evidence points toward significant long term harms associated with this method of treatment, including an increased risk of recurrence, rupture and worsened clinical outcomes (1, 2). Our primary purpose was to summarise the known effects of locally administered glucocorticoid on tendon tissue and tendon cells.Summary Statement
Introduction
The aim of this study was to compare patterns (aligned, random and grid) of electrospun polydioxanone scaffolds for tendon repair. The aligned design was optimal, directing cell shape, orientation and protein expression. Moreover, it naturally crimped, presenting tendon-like morphology. Nanofibrous electrospun materials have been previously proposed as potential scaffolds for tendon repair, with emphasis on biomimetic design, postulated to encourage tissue regeneration. In this study, we characterised the interaction of primary tendon-derived cells with polydioxanone (PDO) scaffolds. PDO is a polymer with an excellent Summary Statement
Introduction
The dGEMRIC index correlates more strongly with the pattern of radiographic joint space narrowing in hip osteoarthritis at five year follow-up than morphological measurements of the proximal femur. It therefore offers potential to refine predictive models of hip osteoarthritis progression. Longitudinal general population studies have shown that femoroacetabular impingement increases the risk of developing hip osteoarthritis, however, morphological parameters have a low positive predictive value. Arthroscopic debridement of impingement lesions has been proposed as a potential strategy for the prevention of osteoarthritis, however, the development of such strategies requires the identification of individuals at high risk of disease progression. We investigated whether delayed Gadolinium-Enhanced MRI of Cartilage (dGEMRIC) predicts disease progression. This imaging modality is an indirect measure of cartilage glycosaminoglycan content.Summary
Introduction
The peripheral neuronal phenotype is significantly altered in rotator cuff tendinopathy (RCT) with a clear upregulation of the Glutaminergic system being present in disease. Shoulder pain is the third most frequent cause of chronic musculoskeletal pain in the community and is usually caused by rotator cuff tendinopathy (RCT). The central and peripheral nervous system play an important role in both tissue homoeostasis and tendon healing. The Glutaminergic system is of key importance in driving the peripheral and central neuronal changes which increase the body's sensitivity to pain (1, 2). No study to date has investigated the role of the glutaminergic system in human RCT. We hypothesised that the peripheral neuronal phenotype would be altered in RCT, and would vary according to disease stage as measured by size of tear. The term ‘peripheral neuronal phenotype’ is used to refer to refer to specific characteristics of the peripheral nervous system, neuronal mediators and the receptors for these mediators in peripheral tissueSummary Statement
Introduction
This study describes the design and preliminary in vitro testing of a novel patch for the repair of rotator cuff tendon tears. The laminated design incorporates woven and electrospun components. The woven element provides the patch with excellent mechanical strength and the electrospun layer improves cell attachment and promotes cell orientation and diferentiation. Aligned nanofibrous electrospun scaffolds have been previously proposed as ideal scaffolds for tendon repair, replicating the anisotropy of tendon and providing a biomimetic design to encourage tissue regeneration (Hakimi et al., 2012). However, such scaffolds are still limited in terms of mechanical properties. This paper presents the design of a novel patch for rotator cuff repair in which the electrospun scaffold is supported by a woven component.Summary Statement
Introduction
A novel biomimetic polydioxanone tendon patch with woven and electrospun components is biocompatible, recapitulates native tendon architecture and creates a tissue-healing microenvironment directed by a subpopulation of regenerative macrophages. The woven component provides tensile strength while the tendon heals. There is great interest in the use of biomimetic devices to augment tendon repairs. Ideally, implants improve healing without causing adverse local or systemic reactions. Biocompatibility remains a critical issue prior to implantation into humans, as some implants elicit a foreign body response (FBR) involving inflammation, poor wound healing and even fistulae formation. Additionally, the effect on articular cartilage locally or systemically with placement of a juxta-articular implant has not been examined. The purpose of this study is to test the Summary Statement
Introduction
