As dense connective tissues connecting bone to muscle and bone to bone, respectively, tendon and ligament (T/L) arise from the somitic mesoderm, originating in a recently discovered somitic compartment, the syndetome. Inductive signals from the adjacent sclerotome and myotome upregulate expression of Scleraxis, a key transcription factor for tenogenic and ligamentogenic differentiation. Underst...

Changes in the concentration of the major glycosaminoglycan compounds were measured during healing of severed Achilles tendons in rabbits. Using zone electrophoresis for separation, and densitometry for quantitation of these compounds, their concentrations could be measured in each of several portions of the tendon and its associated muscle. Immediately after injury, the concentration of hyalur...

Entheses are complex structures which act to reduce stress concentrations between tendon and skeleton tissues. Understanding the development and function of the enthesis organ has implications for surgical repair, particularly in regards to healing and the regulation of tendon to bone engraftment. In this paper we review the development and function of entheses as well as the enthesis organ con...

Platelet Rich Fibrin (PRF) is a new biological augmentation material which is remarkable with its rich cellular components and growth factors. The aim of this study was to evaluate the effect of PRF on tendon healing in a rat model. PRF and control groups included eight rats. PRF was obtained with centrifuging blood collected from the rats and applied on the tendon repair site in Achilles tendo...

BACKGROUND AND PURPOSE Should blockade of TNF-α be avoided after orthopedic surgery? Healing of injuries in soft tissues and bone starts with a brief inflammatory phase. Modulation of inflammatory signaling might therefore interfere with healing. For example, Cox inhibitors impair healing in animal models of tendon, ligament, and bone injury, as well as in fracture patients. TNF-α is expressed ...

Tendon is a uniaxial connective tissue component of the musculoskeletal system. Tendon is involved in force transmission between muscle and bone. Tendon injury is very common and debilitating but tendon repair remains a clinical challenge for orthopedic medicine. In vertebrates, tendon is mainly composed of type I collagen fibrils, displaying a parallel organization along the tendon axis. The t...

Nitric oxide (NO) is a small free radical generated by a family of enzymes, the nitric oxide synthases (NOSs). Following injury to a tendon, NO is induced by all three isoforms of NOS and NOS activity is also upregulated in tendinopathy. In animal models when NOS activity is inhibited by competitive inhibitors of NOS, tendon healing is reduced. When additional NO is added, tendon healing is enh...

Tendon healing is fraught with complications such as reruptures and adhesion formation due to the formation of scar tissue at the injury site as opposed to the regeneration of native tissue. Stem cells are an attractive option in developing cell-based therapies to improve tendon healing. However, several questions remain to be answered before stem cells can be used clinically. Specifically, the...

During neonatal development, tendons undergo a well orchestrated process whereby extensive structural and compositional changes occur in synchrony to produce a normal tissue. Conversely, during the repair response to injury, structural and compositional changes occur, but a mechanically inferior tendon is produced. As a result, developmental processes have been postulated as a potential paradig...

We studied bone-tendon healing using immunohistochemical methods in a rabbit model. Reconstruction of the anterior cruciate ligament was undertaken using semitendinosus tendon in 20 rabbits. Immunohistochemical evaluations were performed at one, two, four and eight weeks after the operation. The expression of CD31, RAM-11, VEGF, b-FGF, S-100 protein and collagen I, II and III in the bone-tendon...