This study intended to investigate the effect of vericiguat (VIT) on titanium rod osseointegration in aged rats with iron overload, and also explore the role of VIT in osteoblast and osteoclast differentiation. In this study, 60 rats were included in a titanium rod implantation model and underwent subsequent guanylate cyclase treatment. Imaging, histology, and biomechanics were used to evaluate the osseointegration of rats in each group. First, the impact of VIT on bone integration in aged rats with iron overload was investigated. Subsequently, VIT was employed to modulate the differentiation of MC3T3-E1 cells and RAW264.7 cells under conditions of iron overload.Aims
Methods
In this study, we compared the pain behaviour and osteoarthritis (OA) progression between anterior cruciate ligament transection (ACLT) and osteochondral injury in surgically-induced OA rat models. OA was induced in the knee joints of male Wistar rats using transection of the ACL or induction of osteochondral injury. Changes in the percentage of high limb weight distribution (%HLWD) on the operated hind limb were used to determine the pain behaviour in these models. The development of OA was assessed and compared using a histological evaluation based on the Osteoarthritis Research Society International (OARSI) cartilage OA histopathology score.Objectives
Methods
This study aimed to examine the effects of SRT1720, a potent SIRT1 activator, on osteoarthritis (OA) progression using an experimental OA model. Osteoarthritis was surgically induced by destabilization of the medial meniscus in eight-week-old C57BL/6 male mice. SRT1720 was administered intraperitoneally twice a week after surgery. Osteoarthritis progression was evaluated histologically using the Osteoarthritis Research Society International (OARSI) score at four, eight, 12 and 16 weeks. The expression of SIRT1, matrix metalloproteinase 13 (MMP-13), a disintegrin and metalloproteinase with thrombospondin motifs-5 (ADAMTS-5), cleaved caspase-3, PARP p85, and acetylated nuclear factor (NF)-κB p65 in cartilage was examined by immunohistochemistry. Synovitis was also evaluated histologically. Primary mouse epiphyseal chondrocytes were treated with SRT1720 in the presence or absence of interleukin 1 beta (IL-1β), and gene expression changes were examined by real-time polymerase chain reaction (PCR).Objectives
Methods
To explore whether orthopaedic surgeons have adopted the Proximal Fracture of the Humerus: Evaluation by Randomisation (PROFHER) trial results routinely into clinical practice. A questionnaire was piloted with six orthopaedic surgeons using a ‘think aloud’ process. The final questionnaire contained 29 items and was distributed online to surgeon members of the British Orthopaedic Association and British Elbow and Shoulder Society. Descriptive statistics summarised the sample characteristics and fracture treatment of respondents overall, and grouped them by whether they changed practice based on PROFHER trial findings. Free-text responses were analysed qualitatively for emerging themes using Framework Analysis principles.Objectives
Methods
After an injury, the biological reattachment of tendon to bone is a challenge because healing takes place between a soft (tendon) and a hard (bone) tissue. Even after healing, the transition zone in the enthesis is not completely regenerated, making it susceptible to re-injury. In this study, we aimed to regenerate Achilles tendon entheses (ATEs) in wounded rats using a combination of kartogenin (KGN) and platelet-rich plasma (PRP). Wounds created in rat ATEs were given three different treatments: kartogenin platelet-rich plasma (KGN-PRP); PRP; or saline (control), followed by histological and immunochemical analyses, and mechanical testing of the rat ATEs after three months of healing.Objectives
Methods
Sustained intra-articular delivery of pharmacological agents is an attractive modality but requires use of a safe carrier that would not induce cartilage damage or fibrosis. Collagen scaffolds are widely available and could be used intra-articularly, but no investigation has looked at the safety of collagen scaffolds within synovial joints. The aim of this study was to determine the safety of collagen scaffold implantation in a validated A total of 96 rabbits were randomly and equally assigned to four different groups: arthrotomy alone; arthrotomy and collagen scaffold placement; contracture surgery; and contracture surgery and collagen scaffold placement. Animals were killed in equal numbers at 72 hours, two weeks, eight weeks, and 24 weeks. Joint contracture was measured, and cartilage and synovial samples underwent histological analysis.Objectives
Materials and Methods
Ubiquitin E3 ligase-mediated protein degradation regulates osteoblast function. Itch, an E3 ligase, affects numerous cell functions by regulating ubiquitination and proteasomal degradation of related proteins. However, the Itch-related cellular and molecular mechanisms by which osteoblast differentiation and function are elevated during bone fracture repair are as yet unknown. We examined the expression levels of E3 ligases and NF-κB members in callus samples during bone fracture repair by quantitative polymerase chain reaction (qPCR) and the total amount of ubiquitinated proteins by Western blot analysis in wild-type (WT) mice. The expression levels of osteoblast-associated genes in fracture callus from Itch knockout (KO) mice and their WT littermates were examined by qPCR. The effect of NF-κB on Itch expression in C2C12 osteoblast cells was determined by a chromatin immunoprecipitation (ChIP) assay.Objectives
Methods
Mesenchymal stem cells have the ability to differentiate into various cell types, and thus have emerged as promising alternatives to chondrocytes in cell-based cartilage repair methods. The aim of this experimental study was to investigate the effect of bone marrow derived mesenchymal stem cells combined with platelet rich fibrin on osteochondral defect repair and articular cartilage regeneration in a canine model. Osteochondral defects were created on the medial femoral condyles of 12 adult male mixed breed dogs. They were either treated with stem cells seeded on platelet rich fibrin or left empty. Macroscopic and histological evaluation of the repair tissue was conducted after four, 16 and 24 weeks using the International Cartilage Repair Society macroscopic and the O’Driscoll histological grading systems. Results were reported as mean and standard deviation (Objectives
Methods
Objectives. All-suture anchors are increasingly used in rotator cuff repair procedures. Potential benefits include decreased bone damage. However, there is limited published evidence for the relative strength of fixation for all-suture anchors compared with traditional anchors. Materials and Methods. A total of four commercially available all-suture anchors, the ‘Y-Knot’ (ConMed), Q-FIX (Smith & Nephew), ICONIX (Stryker) and JuggerKnot (Zimmer Biomet) and a traditional anchor control TWINFIX Ultra PK
Osteophytes are products of active endochondral and intramembranous ossification, and therefore could theoretically provide significant efficacy as bone grafts. In this study, we compared the bone mineralisation effectiveness of osteophytes and cancellous bone, including their effects on secretion of growth factors and anabolic effects on osteoblasts. Osteophytes and cancellous bone obtained from human patients were transplanted onto the calvaria of severe combined immunodeficient mice, with Calcein administered intra-peritoneally for fluorescent labelling of bone mineralisation. Conditioned media were prepared using osteophytes and cancellous bone, and growth factor concentration and effects of each graft on proliferation, differentiation and migration of osteoblastic cells were assessed using enzyme-linked immunosorbent assays, MTS ((3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium)) assays, quantitative real-time polymerase chain reaction, and migration assays.Objectives
Methods
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
This study aimed to evaluate the histological and mechanical features of tendon healing in a rabbit model with second-harmonic-generation (SHG) imaging and tensile testing. A total of eight male Japanese white rabbits were used for this study. The flexor digitorum tendons in their right leg were sharply transected, and then were repaired by intratendinous stitching. At four weeks post-operatively, the rabbits were killed and the flexor digitorum tendons in both right and left legs were excised and used as specimens for tendon healing (n = 8) and control (n = 8), respectively. Each specimen was examined by SHG imaging, followed by tensile testing, and the results of the two testing modalities were assessed for correlation.Objectives
Materials and 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
Objectives. During open orthopaedic surgery, joints may be exposed to air, potentially leading to cartilage drying and chondrocyte death, however, the long-term effects of joint drying in vivo are poorly understood. We used an animal model to investigate the subsequent effects of joint drying on cartilage and chondrocytes. Methods. The patellar groove of anaesthetised rats was exposed (sham-operated), or exposed and then subjected to laminar airflow (0.25m/s; 60 minutes) before wounds were
Healing in cancellous metaphyseal bone might be different from
midshaft fracture healing due to different access to mesenchymal
stem cells, and because metaphyseal bone often heals without a cartilaginous
phase. Inflammation plays an important role in the healing of a
shaft fracture, but if metaphyseal injury is different, it is important
to clarify if the role of inflammation is also different. The biology
of fracture healing is also influenced by the degree of mechanical
stability. It is unclear if inflammation interacts with stability-related
factors. We investigated the role of inflammation in three different models:
a metaphyseal screw pull-out, a shaft fracture with unstable nailing
(IM-nail) and a stable external fixation (ExFix) model. For each,
half of the animals received dexamethasone to reduce inflammation,
and half received control injections. Mechanical and morphometric evaluation
was used.Objectives
Methods
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. 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 hybrid canines were randomly divided
into an experimental group and a control group. BMSCs were obtained
from the iliac crest of each animal, and only those of the third
generation were used in experiments. An articular osteochondral
defect was created in the right knee of dogs in both groups. Those
in the experimental group were treated by implanting the composites
consisting of the lamellar scaffold of ß-TCP/col I/col II/BMSCs.
Those in the control group were left untreated.Objectives
Methods
Reported rates of dislocation in hip hemiarthroplasty
(HA) for the treatment of intra-capsular fractures of the hip, range
between 1% and 10%. HA is frequently performed through a direct
lateral surgical approach. The aim of this study is to determine
the contribution of the anterior capsule to the stability of a cemented
HA through a direct lateral approach. A total of five whole-body cadavers were thawed at room temperature,
providing ten hip joints for investigation. A Thompson HA was cemented
in place via a direct lateral approach. The cadavers were then positioned
supine, both knee joints were disarticulated and a digital torque
wrench was attached to the femur using a circular frame with three
half pins. The wrench applied an external rotation force with the
hip in extension to allow the hip to dislocate anteriorly. Each
hip was dislocated twice; once with a capsular repair and once without
repairing the capsule. Stratified sampling ensured the order in
which this was performed was alternated for the paired hips on each
cadaver. Comparing peak torque force in hips with the capsule repaired
and peak torque force in hips without repair of the capsule, revealed
a significant difference between the ‘capsule repaired’ (mean 22.96
Nm, standard deviation ( Cite this article:
The aim of this experimental study on New Zealand’s white rabbits
was to investigate the transplantation of autogenous growth plate
cells in order to treat the injured growth plate. They were assessed
in terms of measurements of radiological tibial varus and histological
characteristics. An experimental model of plate growth medial partial resection
of the tibia in 14 New Zealand white rabbits was created. During
this surgical procedure the plate growth cells were collected and
cultured. While the second surgery was being performed, the autologous
cultured growth plate cells were grafted at the right tibia, whereas
the left tibia was used as a control group. Objectives
Methods
