The treatment of osteoporotic fractures is a major challenge, and the enhancement of healing is critical as a major goal in modern fracture management. Most osteoporotic fractures occur at the metaphyseal bone region but few models exist and the healing is still poorly understood. A systematic review was conducted to identify and analyse the appropriateness of current osteoporotic metaphyseal fracture animal models. A literature search was performed on the Pubmed, Embase, and Web of Science databases, and relevant articles were selected. A total of 19 studies were included. Information on the animal, induction of osteoporosis, fracture technique, site and fixation, healing results, and utility of the model were extracted.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
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
The purpose of this study was to compare the results and complications of tibial lengthening over an intramedullary nail with treatment using the traditional Ilizarov method. In this matched case study, 16 adult patients underwent 19 tibial lengthening over nails (LON) procedures. For the matched case group, 17 patients who underwent 19 Ilizarov tibial lengthenings were retrospectively matched to the LON group.Objectives
Methods
This review is aimed at clinicians appraising
preclinical trauma studies and researchers investigating compromised bone
healing or novel treatments for fractures. It categorises the clinical
scenarios of poor healing of fractures and attempts to match them
with the appropriate animal models in the literature. We performed an extensive literature search of animal models
of long bone fracture repair/nonunion and grouped the resulting
studies according to the clinical scenario they were attempting
to reflect; we then scrutinised them for their reliability and accuracy
in reproducing that clinical scenario. Models for normal fracture repair (primary and secondary), delayed
union, nonunion (atrophic and hypertrophic), segmental defects and
fractures at risk of impaired healing were identified. Their accuracy
in reflecting the clinical scenario ranged greatly and the reliability
of reproducing the scenario ranged from 100% to 40%. It is vital to know the limitations and success of each model
when considering its application.
Soaking bone grafts in a bisphosphonate solution before implantation can prevent their resorption and increase the local bone density in rats and humans. However, recent studies suggest that pre-treatment of allografts with bisphosphonate can prevent bone ingrowth into impaction grafts. We tested the hypothesis that excessive amounts of bisphosphonate would also cause a negative response in less dense grafts. We used a model where non-impacted metaphyseal bone grafts were randomised into three groups with either no bisphosphonate, alendronate followed by rinsing, and alendronate without subsequent rinsing, and inserted into bone chambers in rats. The specimens were evaluated histologically at one week, and by histomorphometry and radiology at four weeks. At four weeks, both bisphosphonate groups showed an increase in the total bone content, increased newly formed bone, and higher radiodensity than the controls. In spite of being implanted in a chamber with a limited opportunity to diffuse, even an excessive amount of bisphosphonate improved the outcome. We suggest that the negative results seen by others could be due to the combination of densely compacted bone and a bisphosphonate. We suggest that bisphosphonates are likely to have a negative influence where resorption is a prerequisite to create space for new bone ingrowth.
