Objectives. The major problem with repair of an articular cartilage injury
is the extensive difference in the structure and function of regenerated,
compared with normal cartilage. Our work investigates the feasibility
of repairing articular osteochondral defects in the canine knee
joint using a composite lamellar scaffold of nano-ß-tricalcium phosphate
(ß-TCP)/collagen (col) I and II with bone marrow stromal stem cells
(BMSCs) and assesses its biological compatibility. Methods. The bone–cartilage scaffold was prepared as a laminated composite,
using hydroxyapatite nanoparticles (nano-HAP)/collagen I/copolymer
of polylactic acid–hydroxyacetic acid as the bony scaffold, and
sodium hyaluronate/poly(lactic-co-glycolic acid) as the cartilaginous
scaffold. Ten-to 12-month-old
Rotator cuff tears are among the most frequent upper extremity injuries. Current treatment strategies do not address the poor quality of the muscle and tendon following chronic rotator cuff tears. Hypoxia-inducible factor-1 alpha (HIF-1α) is a transcription factor that activates many genes that are important in skeletal muscle regeneration. HIF-1α is inhibited under normal physiological conditions by the HIF prolyl 4-hydroxylases (PHDs). In this study, we used a pharmacological PHD inhibitor, GSK1120360A, to enhance the activity of HIF-1α following the repair of a chronic cuff tear, and measured muscle fibre contractility, fibrosis, gene expression, and enthesis mechanics. Chronic supraspinatus tears were induced in adult rats, and repaired 28 days later. Rats received 0 mg/kg, 3 mg/kg, or 10 mg/kg GSK1120360A daily. Collagen content, contractility, fibre type distribution and size, the expression of genes involved in fibrosis, lipid accumulation, atrophy and inflammation, and the mechanical properties of the enthesis were then assessed two weeks following surgical repair.Objectives
Methods
Rotator cuff tears are among the most common and debilitating
upper extremity injuries. Chronic cuff tears result in atrophy and
an infiltration of fat into the muscle, a condition commonly referred
to as ‘fatty degeneration’. While stem cell therapies hold promise
for the treatment of cuff tears, a suitable immunodeficient animal
model that could be used to study human or other xenograft-based
therapies for the treatment of rotator cuff injuries had not previously
been identified. A full-thickness, massive supraspinatus and infraspinatus tear
was induced in adult T-cell deficient rats. We hypothesised that,
compared with controls, 28 days after inducing a tear we would observe
a decrease in muscle force production, an accumulation of type IIB
fibres, and an upregulation in the expression of genes involved
with muscle atrophy, fibrosis and inflammation.Objectives
Methods
We sought to determine if a durable bilayer implant composed of trabecular metal with autologous periosteum on top would be suitable to reconstitute large osteochondral defects. This design would allow for secure implant fixation, subsequent integration and remodeling. Adult sheep were randomly assigned to one of three groups (n = 8/group): 1. trabecular metal/periosteal graft (TMPG), 2. trabecular metal (TM), 3. empty defect (ED). Cartilage and bone healing were assessed macroscopically, biochemically (type II collagen, sulfated glycosaminoglycan (sGAG) and double-stranded DNA (dsDNA) content) and histologically.Objectives
Materials and Methods
To review the systemic impact of smoking on bone healing as evidenced
within the orthopaedic literature. A protocol was established and studies were sourced from five
electronic databases. Screening, data abstraction and quality assessment
was conducted by two review authors. Prospective and retrospective
clinical studies were included. The primary outcome measures were
based on clinical and/or radiological indicators of bone healing.
This review specifically focused on non-spinal orthopaedic studies.Objectives
Methods