The progressive degenerative process of the spine is physiological. It usually begins in the second decade of life in the intervertebral disc, producing protrusions and herniations that cause a decrease in the intervertebral disc. This situation causes an increase in pressure on the facet joints that results in greater wear of their cartilage. Synovitis occurs in the joint and irritation of the capsule, causing facet pain.
Deterioration of the facet joint cartilage causes joint laxity and subluxation. This hypermobility causes osteophytes and joint sclerosis, producing facet hypertrophy. This instability exceeds physiological limits and pain appears.
Forced flexion and hyperextension postures, especially those related to weight manipulation, increase the load on the facet joints and can accelerate lumbar facet osteoarthritis.
Lumbar facet syndrome can be the origin of facet arthrosis, inflammation and back pain.
To understand the process of arthrosis in the facets of the spine, it is important to refer to the minor nerve branches that are integrated into the different spinal nerves of each vertebral segment:
- Posterior branch: Innervates the facet joints, spinous ligaments, ligamentum flavum, lumbar muscles, and skin.
- Sinuvertebral nerve of Luschka: supplies the most posterior and lateral area of the annulus fibrosus.
The transmission of pain collected through the posterior branch can be perceived as local pain (low back pain) and/or referred pain. The inflammation or wear of the articular facets activates the nerves that transmit the stimuli to the joint and can trigger said discomfort. The action on the posterior ramus should block the conduction of pain information from the facet joint.