Increased Bone density in X-ray seen in -a) Increased thickening of trabeculaeb) Fracture & Collapse of cancellous bonec) Defective mineralizationd) Myossitis ossificanse) Relative disuse atrophy & surrounding bone response
Increased bone density

Increased bone density refers to that part of the bone or whole bone appears more dense on x-ray.
While an increase in bone density occurs less frequently, many examples are seen in which this is used as an aid in radiographic diagnosis.
The increase in bone density can occur by several different mechanisms and be the result of different insult to the bone.
Most commonly, the increase in density occurs within the trabecular bone (spongy bone / cancellous bone) following :-


Thickening of trabeculae
Increased number of trabeculae



Increased in the density within the cortical bone occurs uncommonly because normally the bone is so compact that no space exists that permits the addition of more bone tissue.
However, It is possible for cortex to become thicker as a result of the addition ofperiosteal or endosteal new bone when it is actually a reactive change. This is considered as increased bone density by some people. Actually it is not true increase in bone density but increase in the thickness, i.e. density of cortical bone remains the same but thickness increases.
So, pathogenic mechanism of increased bone density may be :-


Increased density of cancellous bone either due to thickening of trabeculae or increased number of trabeculae.
Thickening and expansion of cortex due to periosteal reaction or endosteal reaction.


Important causes of increased density are :-
Generalized increased in bone density
Renal osteodystrophy                                       o Hypercalcemia & Hypervitaminosis D
Flourosis                                                              o Hyperphosphatasia
Mastocytosis                                                        o Hodgkin disease
Myelosclerosis                                                    o Heavy metal poisoning (Lead)
Sclerotic metastasis                                             o Infantile cortical hyperostosis (Caffey disease)
Myeloid metaplasia                                            o Melorheostosis (Leri disease)
Osteopertrosis (Marble bone disease)           o Hyperparathyroidm (Secondary)
Gaucher disease                                                   o Hypoparathyrodism
Healing phase of rickets                                     o Osteopetrosis

Localized increased in bone density

Avascular necrosis                                              o Heavy metal poisoning (lead)
Bone infarct                                                         o Mastocytosis
Callus formation                                                 o Melorheostosis
Exostosis                                                               o Osteoid osteoma
Ewing sarcoma                                                    o Osteoblastoma
Fibrous dysplasia                                                 o Osteoblastic metastasis
Gardner syndrme                                                 o Osteomyelitis (sequestrum)
Healed osteomyelitis                                          o Paget's disease
Eosinophilic granuloma
Collapse of cancellous bone causes trabeculae to come together, therefore increased density.
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