Aims. It is increasingly appreciated that coordinated regulation of angiogenesis and osteogenesis is needed for bone formation. How this regulation is achieved during peri-implant bone healing, such as osseointegration, is largely unclear. This study examined the relationship between angiogenesis and osteogenesis in a unique model of osseointegration of a mouse tibial implant by pharmacologically blocking the vascular endothelial growth factor (VEGF) pathway. Materials and Methods. An implant was inserted into the right tibia of 16-week-old female C57BL/6 mice (n = 38). Mice received anti-VEGF receptor-1 (VEGFR-1) antibody (25 mg/kg) and VEGF receptor-2 (VEGFR-2) antibody (25 mg/kg; n = 19) or an isotype control antibody (n = 19). Flow cytometric (n = 4/group) and immunofluorescent (n = 3/group) analyses were performed at two weeks post-implantation to detect the distribution and density of
The LockDown device (previously called Surgilig)
is a braided polyester mesh which is mostly used to reconstruct the
dislocated acromioclavicular joint. More than 11 000 have been implanted
worldwide. Little is known about the tissue reaction to the device
nor to its wear products when implanted in an extra-articular site
in humans. This is of importance as an adverse immunological reaction
could result in osteolysis or damage to the local tissues, thereby affecting
the longevity of the implant. We analysed the histology of five LockDown implants retrieved
from five patients over the last seven years by one of the senior
authors. Routine analysis was carried out in all five cases and
immunohistochemistry in one. The LockDown device acts as a scaffold for connective tissue
which forms an investing fibrous pseudoligament. The immunological
response at the histological level seems favourable with a limited
histiocytic and giant cell response to micron-sized wear particles.
The connective tissue envelope around the implant is less organised
than a native ligament. Cite this article:
The belief that an intervertebral disc must degenerate
before it can herniate has clinical and medicolegal significance,
but lacks scientific validity. We hypothesised that tissue changes
in herniated discs differ from those in discs that degenerate without
herniation. Tissues were obtained at surgery from 21 herniated discs
and 11 non-herniated discs of similar degeneration as assessed by
the Pfirrmann grade. Thin sections were graded histologically, and
certain features were quantified using immunofluorescence combined
with confocal microscopy and image analysis. Herniated and degenerated
tissues were compared separately for each tissue type: nucleus, inner
annulus and outer annulus. Herniated tissues showed significantly greater proteoglycan loss
(outer annulus), neovascularisation (annulus), innervation (annulus),
cellularity/inflammation (annulus) and expression of matrix-degrading
enzymes (inner annulus) than degenerated discs. No significant differences
were seen in the nucleus tissue from herniated and degenerated discs.
Degenerative changes start in the nucleus, so it seems unlikely
that advanced degeneration caused herniation in 21 of these 32 discs.
On the contrary, specific changes in the annulus can be interpreted
as the consequences of herniation, when disruption allows local
swelling, proteoglycan loss, and the ingrowth of blood vessels,
nerves and inflammatory cells. In conclusion, it should not be assumed that degenerative changes
always precede disc herniation. Cite this article:
The scarcity of mesenchymal stem cells (MSCs) in iliac crest bone marrow aspirate (ICBMA), and the expense and time in culturing cells, has led to the search for alternative harvest sites. The reamer-irrigation-aspirator (RIA) provides continuous irrigation and suction during reaming of long bones. The aspirated contents pass via a filter, trapping bony fragments, before moving into a ‘waste’ bag from which MSCs have been previously isolated. We examined the liquid and solid phases, performed a novel digestion of the solid phase, and made a comparative assessment in terms of number, phenotype and differentiation capacity with matched ICBMA. The solid fraction from the filtrate was digested for 60 minutes at 37°C with collagenase. Enumeration was performed via the colony-forming unit fibroblast (CFU-F) assay. Passage (P2) cells were differentiated towards osteogenic, adipogenic and chondrogenic lineages, and their phenotypes assessed using flow cytometry (CD33, CD34, CD45, CD73, CD90, and CD105). MSCs from the RIA phases were able to differentiate at least as well as those from ICBMA, and all fractions had phenotypes consistent with other established sources. The median number of colonies for the three groups was: ICBMA = 8.5 (2 to 86), RIA-liquid = 19.5 (4 to 90), RIA-solid = 109 (67 to 200) per 200 μl. The mean total yield of cells for the three groups was: ICBMA = 920 (0 to 4275), RIA-liquid = 114 983 (16 500 to 477 750), RIA-solid = 12 785 (7210 to 28 475). The RIA filtrate contains large numbers of MSCs that could potentially be extracted without enzymatic digestion and used for bone repair without prior cell expansion.
We report a case of bifocal rhabdomyosarcoma involving the hand and thigh in an 11-year-old female. We highlight the importance of a thorough clinical examination and an aggressive surgical approach in which each lesion is treated as a separate primary.
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
