Proliferation, migration, and differentiation of anterior cruciate ligament (ACL) remnant and surrounding cells are fundamental processes for ACL reconstruction; however, the interaction between ACL remnant and surrounding cells is unclear. We hypothesized that ACL remnant cells preserve the capability to regulate the surrounding cells’ activity, collagen gene expression, and tenogenic differentiation. Moreover, extracorporeal shock wave (ESW) would not only promote activity of ACL remnant cells, but also enhance their paracrine regulation of surrounding cells. Cell viability, proliferation, migration, and expression levels of Collagen-I (COL-I) A1, transforming growth factor beta (TGF-β), and vascular endothelial growth factor (VEGF) were compared between ACL remnant cells untreated and treated with ESW (0.15 mJ/mm2, 1,000 impulses, 4 Hz). To evaluate the subsequent effects on the surrounding cells, bone marrow stromal cells (BMSCs)’ viability, proliferation, migration, and levels of Type I Collagen, Type III Collagen, and tenogenic gene (Aims
Methods
Re-rupture is common after primary flexor tendon repair. Characterization of the biological changes in the ruptured tendon stumps would be helpful, not only to understand the biological responses to the failed tendon repair, but also to investigate if the tendon stumps could be used as a recycling biomaterial for tendon regeneration in the secondary grafting surgery. A canine flexor tendon repair and failure model was used. Following six weeks of repair failure, the tendon stumps were analyzed and characterized as isolated tendon-derived stem cells (TDSCs).Objectives
Methods
Injury to the anterior cruciate ligament (ACL)
is one of the most devastating and frequent injuries of the knee. Surgical
reconstruction is the current standard of care for treatment of
ACL injuries in active patients. The widespread adoption of ACL
reconstruction over primary repair was based on early perception
of the limited healing capacity of the ACL. Although the majority
of ACL reconstruction surgeries successfully restore gross joint stability,
post-traumatic osteoarthritis is commonplace following these injuries,
even with ACL reconstruction. The development of new techniques
to limit the long-term clinical sequelae associated with ACL reconstruction
has been the main focus of research over the past decades. The improved
knowledge of healing, along with recent advances in tissue engineering
and regenerative medicine, has resulted in the discovery of novel
biologically augmented ACL-repair techniques that have satisfactory
outcomes in preclinical studies. This instructional review provides
a summary of the latest advances made in ACL repair. Cite this article:
The injured anterior cruciate ligament (ACL) is thought to exhibit an impaired healing response, and attempts at surgical repair have not been successful. Connective tissue growth factor (CTGF) is reported to be associated with wound healing, probably through transforming growth factor beta 1 (TGF-β1). A rabbit ACL injury model was used to study the effect of CTGF on ligament recovery. Quantitative real-time PCR (qRT-PCR) was performed for detection of changes in RNA levels of TGF-β1, type 1 collagen (COL1), type 2 collagen (COL2), SRY-related high mobility group-box gene9 (SOX9), tissue inhibitor of metalloproteinase-1 (TIMP-1) and matrix metallopeptidase 13 (MMP-13). Expression of related proteins was detected by Western blotting.Objectives
Methods
This study aimed to investigate time-dependent gene expression
of injured human anterior cruciate ligament (ACL), and to evaluate
the histological changes of the ACL remnant in terms of cellular
characterisation. Injured human ACL tissues were harvested from 105 patients undergoing
primary ACL reconstruction and divided into four phases based on
the period from injury to surgery. Phase I was <
three weeks,
phase II was three to eight weeks, phase III was eight to 20 weeks,
and phase IV was ≥ 21 weeks. Gene expressions of these tissues were
analysed in each phase by quantitative real-time polymerase chain
reaction using selected markers (collagen types 1 and 3, biglycan,
decorin, α-smooth muscle actin, IL-6, TGF-β1, MMP-1, MMP-2 and TIMP-1).
Immunohistochemical staining was also performed using primary antibodies
against CD68, CD55, Stat3 and phosphorylated-Stat3 (P-Stat3). Objectives
Methods
The purpose of this study was to evaluate chronological changes
in the collagen-type composition at tendon–bone interface during
tendon–bone healing and to clarify the continuity between Sharpey-like
fibres and inner fibres of the tendon. Male white rabbits were used to create an extra-articular bone–tendon
graft model by grafting the extensor digitorum longus into a bone
tunnel. Three rabbits were killed at two, four, eight, 12 and 26
weeks post-operatively. Elastica van Gieson staining was used to colour
5 µm coronal sections, which were examined under optical and polarised
light microscopy. Immunostaining for type I, II and III collagen
was also performed.Objectives
Methods
