Spinal Arthritis Diagnostic Imaging Approach Part I
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Degenerative Arthritis
Spinal Arthritis:
Spondylosis aka Degenerative disease of the spine represents an evolution of changes affecting most mobile spinal segments beginning with:
Intervertebral disc (IVD) dehydration (desiccation) and degeneration aka Degenerative Disc Disease (DDD) with an abnormal increase in mechanical stress and degeneration of posterior elements affecting 4-mobile synovial articulations ( true osteoarthritis)
2-Facets in the L/S & 2-Facets & 2-Uncovertebral joints in the C/S
Imaging plays a significant role in the diagnosis, grading, and evaluation of neurological complications (e.g., spondylotic myelopathy/radiculopathy)
X-radiography with AP, Lateral & Oblique spinal views provides Dx and classification of Spondylosis
MR imaging may help to evaluate the degree of neurological changes associated with degenerative spinal canal and neural foraminal stenosis
Spinal motion segment:
2-adjacent vertebrae
IVD (fibrocartilage)
2-facets (synovial)
Pathology: loss of disc height increases mechanical stress on mobile elements
Ligamentum flavum “hypertrophy” or thickening due to buckling
Loss of normal lordosis with or w/o reversal or kyphosis
Vertebral canal & neural foraminal stenosis
Neutral lateral cervical radiograph: note mild to moderate disc narrowing and spondylophyte formation at C5-6 & C6-C7 (most common levels affected by cervical spondylosis). Straightening or flattening with mild reversal of cervical lordosis. Some mild facet proliferation is noted at the above levels
On radiographs: evaluate for disc height (mild, moderate or severe) loss
End-plate sclerosis & spondylophytes; mild, moderate or severe
Facet and uncinate irregularity, hypertrophy/degeneration; mild, moderate or severe
Key Dx: correlate with a clinical presentation: neck/back pain with or w/o neurological disturbance ( myelopathy vs. radiculopathy or both)
Uncinate processes undergo degeneration/proliferation resulting in uncovertebral arthrosis
Early findings present with mild bone proliferation along the cortical margin (white and black arrows) if compared to normal uncinate (orange arrow)
Later, more extensive bone proliferation extending into and narrowing vertebral canal and neural osseous foramina (IVF’s) may be noted. The latter may contribute to spinal/IVF stenosis and potential neurological changes
Posterior oblique views may help further
AP lower cervical (a) and posterior oblique (b) views
Note mild uncinated process proliferation with neural foraminal narrowing (arrows)
Typically if less than a third of IVF becomes narrowed, patients may present w/o significant neurological signs
Lumbar spondylosis is evaluated with AP and lateral views with additional AP L5-S1 spot view to examine lumbosacral junction
Typical features include disc height loss/degeneration
Intra-discal gas (vacuum) phenomenon (blue arrow) along with spondylophytes
Degenerative spondylolisthesis and/or retrolisthesis (green arrow) may follow disc and facet degeneration and can be graded by the Meyerding classification
In most cases, degenerative spondylolisthesis rarely progresses beyond Grade 2
Lumbar facet degeneration seen as bone proliferation/sclerosis and IVF narrowing
MR imaging w/o gad C is an effective modality to evaluate clinical signs of spondylosis & associated neurological complications with pre-surgical evaluation
Case: 50-y.o Fe with neck pain. Case b-45-y.o.M (top a b images). MRI reveals: loss of disc hydration or desiccation, spondylophytes and disc herniation w/o neurological changes
(Bottom images) Left: preoperative and right postoperative MRI slices of the patient presented with clinical signs of cervical spondylotic myelopathy. Note disc herniation, ligam flavum hypertrophy and canal stenosis (left)
Sagittal MRI slice of lumbar DDD manifested with disc desiccation and posterior herniation effacing thecal sac
Correlating sagittal and axial slices will be more informative to evaluate canal stenosis and potential degree of neurological involvement (above-bottom images)
Use the following resources to learn more on MRI evaluation and diagnosis of Degenerative Disc Disease: