Intra-medullary pressure and intra-osseous phlebography in paraplegia

Area of Science:

• Orthopedics
• Vascular Biology
• Neuroscience

Background:

• Paraplegia is associated with osteoporosis, but the underlying mechanisms are not fully understood.
• Bone circulation disturbances may play a role in the development of osteoporosis.
• The autonomic nervous system's role in bone vascularity is an area of ongoing research.

Purpose of the Study:

• To investigate bone circulation in paraplegics using intra-medullary pressure and intra-osseous phlebography.
• To assess the impact of neurological lesions on bone vascularity and blood gases.
• To explore the relationship between circulatory changes and osteoporosis in paraplegia.

Main Methods:

• Studied intra-medullary pressure and intra-osseous phlebography in the femurs of ten paraplegics.
• Analyzed bone blood flow, diaphyseal reflux, and blood gas parameters (O2 saturation, pO2, pCO2).
• Correlated circulatory findings with the presence and severity of osteoporosis.

Main Results:

• Significantly elevated intra-medullary pressure (more than double normal values) was observed.
• Delayed blood flow and diaphyseal reflux indicated venous stasis.
• Altered blood gases (O2 saturation, pO2, pCO2) further supported the presence of circulatory disturbances.
• These circulatory changes were linked to autonomic nervous system lesions below the level of neurological injury.

Conclusions:

• Intra-medullary pressure and intra-osseous phlebography are reliable methods for assessing bone circulation.
• Paraplegia leads to venous stasis and altered blood gases in the bone.
• Autonomic nervous system dysfunction is implicated in these circulatory disturbances.
• Vascular modifications below the neurological lesion appear to influence the development of osteoporosis in paraplegia.