Facet joint arthropathy

Facet joint arthropathy is one of the causes of lower back pain. It occurs from zygapophysial joint space reduction, osteophyte formation and hypertrophy of the articular processes that may cause spinal canal stenosis in severe cases.

Terminology:

Facet arthropathy and facet arthrosis are usually used interchangeably. 

Epidemiology:

It is a common finding in the human lumbar spine that increases in extent and severity over agingageing. About half of the adults younger than 30 years have some degrees of facet arthropathy. Men have a higher prevalence compared to women.

Clinical presentation:

Facet arthropathy is a common cause of lower back pain.

Pathology:

​Repetitive mechanical low-grade trauma and stress over a long period of time has been suggested to play a role in the development of facet joint arthropathy. 

Radiographic features:

Radiography:

Radiography is not sensitive for detection of mild osteoarthritis of the facet joints. It can detect severe cases of facet arthrosis. Oblique views are preferred over standard AP and lateral views. Joint space narrowing, sclerosis, and osteophyte formation are common radiographic findings.

CT:

CT is the best imaging modality for diagnosis and grading of the facet joints. On CT, joint space narrowing, subchondral sclerosis, erosions and osteophytes formations of the facet joints are noted. Air can also be noted inside the joint representing vacuum phenomenon. In addition, neural foramen impingement can also be noted.

MRI:

MRI is less sensitive for the diagnosis of facet arthropathy. However, it better demonstrates narrowing and compression of the thecal sac, lateral recess, neural foramen, and nerve roots.

Single photon emission tomography (SPECT):

SPECT is highly sensitive and specific for the diagnosis of facet joints. However, the images lack adequate resolution.

Treatment: and prognosis

Pharmacologic therapy, steroid injection and radiofrequency ablation are the treatment options.