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Published on: March 23, 2019
Metabolic and haemodynamic changes in the pathologic hypermobile spine
1Department of Orthopaedic Surgery, Rigshospital, and The Institute for Experimental Research in Surgery, University of Copenhagen, Denmark.
Clinical Biomechanics (Bristol, Avon)
|August 7, 2013
Summary
Pathologic lumbar spine hypermobility in goats induced changes resembling osteoarthritis. The study found decreased disc height, hypoxia in the nucleus pulposus, and increased intraosseous pressure in adjacent bone.
Area of Science:
- Biomedical Engineering
- Orthopedics
- Spine Biomechanics
Background:
- Pathologic hypermobility of the lumbar spine is a potential contributor to degenerative changes.
- Understanding the haemodynamic, metabolic, and histologic effects of spinal instability is crucial for developing effective treatments.
Purpose of the Study:
- To investigate whether surgically induced lumbar spine hypermobility in an animal model can replicate changes observed in osteoarthritis.
- To assess the haemodynamic (oxygen partial pressure, intraosseous pressure) and structural (disc height) alterations associated with lumbar instability.
Main Methods:
- Five adult goats underwent laminectomy to create facet joint hypermobility at L4-L5.
- Oxygen partial pressure (pO2) and intraosseous pressure (IOP) were measured in the nucleus pulposus and adjacent lumbar body.
- CT scanning and histologic analysis were used to assess disc height and structural integrity.
- Flexion-extension radiography quantified the degree of hypermobility.
Main Results:
- A 60% increase in lumbar spine hypermobility was achieved and maintained for 7 months.
- Hypermobile discs showed reduced height on CT scans and histologic examination.
- Significant hypoxia (low pO2) was detected in the nucleus pulposus of hypermobile segments.
- Increased pO2 and IOP were observed in the lumbar body adjacent to the hypermobile segment.
Conclusions:
- Surgically induced lumbar spine hypermobility can lead to disc degeneration and altered haemodynamics.
- The findings suggest a link between spinal instability, hypoxia, and increased bone pressure, mirroring aspects of osteoarthritis.
- This animal model provides insights into the pathophysiology of degenerative disc disease and osteoarthritis progression.
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