Revelation of bone loss


What does the lens see in an osteoporotic bone?

Video section: JOURNEY TO THE CENTRE OF AN OSTEOPOROTIC BONE

First of all it sees nothing or rather it sees red. Mobile particles must be washed out without mechanical force, these resulting from and being the consequence of bone destruction. They are essentially fat cells, as has already been said. It bears repeating because it really is fat. It is easier to understand how falling even a short distance can lead to considerable bone lesions…
The field begins to clear and then, under the effect of low pressure lavage, more solid structures – less fragile because of their connections – start to appear.
First of all we see absolutely white structures. These are bone lamellae. They are single or connected to each other, forming plaques which are positioned on top of each other.

The lamellae or plaques are often fracture sites

Different mechanisms may cause different types of fracture
Chemical - Variation in pH
- Variation in 02 and/or CO2 levels
- Release of proteolytic enzymes
Mechanical  
Biological - Macrophage action


On several plaques, an oval shape can be seen, reducing
the thickness of the plaque, which appears to be almost pellucid in this area

On each of the two mineralised plaques, perforated with an even circular hole, two lacunae with uneven edges can be seen, thinning the plaques which are almost transparent.

Note that the outer edge of these lacunae is either at the edge or in contact with the edge of the plaques.
It is easy to see that the plaques are extremely fragile and could break at the slightest impact.

On progressing, non-functional vessels may be seen,
either tight like a washing line between two bone lamellae
or surrounded by adipose cells, remains of the fatty degeneration of the bone lamellae.


These are functional vessels, attached to bone lamellae,
in which red cells are circulating.

In other places, you can see soft tissue, either in the form of fine strips stretched between two lamellae

Tissu conjonctif

or in broad strips or plaques, perforated or not.

You can see fluid of different viscosity from blood flowing from these broken vessels.

These flows will create haematomas,
collections of blood inside the bone.

Blood may flow out of the metaphysis,
either via the large mid-diaphyseal venous sinus,
or through the metaphyseal veins.

They may also be organised
as intraosseous haematomas containing
fractured bone lamellae.

The disappearance of bone lamellae may be due to:

  • either bone degradation products, proteolytic enzymes found in haematomas (see previous image)
  • or micro-clots, micro-thromboses blocking the vessels found
    on bone lamellae (see image opposite)
The micro-thrombosis can be seen as the
black spot on the bone lamella

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