Explain spondylosis, including its pathophysiology, clinical presentation, diagnosis, and management.

Spondylosis: A Comprehensive Overview

Definition and Pathophysiology

Spondylosis is an age-related degenerative cascade of the spine characterized by intervertebral disc degeneration, vertebral body osteophyte formation, and facet joint remodeling that occurs universally by middle age. 1

• Disc degeneration is the primary pathologic event, with secondary changes including marginal osteophyte formation on vertebral bodies and apophyseal joint remodeling 1
• The degenerative process is multifactorial, influenced by genetic, environmental, and occupational factors 2
• Degenerative changes are largely asymptomatic in most cases, though they can progress to cause clinical symptoms 3
• The condition affects both cervical and lumbar regions, with distinct clinical presentations depending on location 2, 4, 5

Cervical Spondylosis Pathophysiology

• Age-related changes result in both static and dynamic compression factors 2
• Direct compressive and ischemic dysfunction of the spinal cord can occur, termed cervical spondylotic myelopathy (CSM) 2
• Neurologic symptoms occur infrequently, usually only in patients with congenital spinal stenosis 4
• The natural history typically involves periods of quiescent disease with intermittent episodes of neurologic decline 2

Lumbar Spondylosis Pathophysiology

• Chronic, noninflammatory disease caused by degeneration of lumbar disc and/or facet joints 5
• Degenerative changes are more marked and occur earlier when vertical or posterior disc prolapse is present 1
• Direct relationship exists between disc degeneration severity, osteophyte formation, and apophyseal joint changes 1

Clinical Presentation

Cervical Spondylosis

• Intermittent neck pain in middle-aged and elderly patients is the most common presentation 4
• May present as subclinical stenosis or follow a more progressive course 2
• Spondylotic radiculopathy causes arm pain and neurologic symptoms when nerve roots are compressed 4
• Cervical spondylotic myelopathy (CSM) is the most serious and disabling manifestation, presenting with progressive myelopathic signs 4

Lumbar Spondylosis

• Patients complain of discomfort in the low back region 5
• Radiating leg pain can occur with nerve root involvement 5
• Neurogenic intermittent claudication develops when lumbar spinal stenosis is present 5

Critical caveat: Involvement of neurologic structures on imaging studies may be asymptomatic, requiring neurologic consultation to rule out other diseases before attributing symptoms to spondylosis 4

Diagnosis

Initial Imaging Approach

• Conventional radiography is the recommended initial imaging modality for suspected spondylosis 6
• For cervical spine: radiographs have 90% sensitivity and specificity for detecting pathology 6
• For lumbar spine: radiographs demonstrate disc space narrowing, osteophytes, and facet joint changes 1

Advanced Imaging

• MRI is the preferred diagnostic study when neurologic symptoms are present 4
• MRI can detect inflammation and structural changes years before radiographic abnormalities appear 6
• MRI without contrast is recommended for evaluating spinal cord, nerve roots, and ligamentous injuries when neurological symptoms exist 6
• CT with multiplanar reformats is necessary for excluding fractures, as radiographs have poor sensitivity for fracture detection 6

Imaging for Specific Complications

• When spinal fracture is suspected, conventional radiography is the initial method; if negative, CT should be performed 7
• For long-term monitoring of structural damage, conventional radiography should not be repeated more frequently than every 2 years 7

Management

Conservative Treatment (First-Line)

Conservative management is the mainstay of treatment, with most patients responding appropriately to nonsurgical measures. 3

Cervical Spondylosis Management

• Activity modification and neck immobilization 4
• Isometric exercises for neck strengthening 4
• Medication including NSAIDs for pain control 4
• For mild CSM with close clinical and radiographic follow-up, conservative treatment is reasonable 2
• Neck immobilization results in improvement in 30-50% of patients with minor neurologic findings 4

Lumbar Spondylosis Management

• Nonsteroidal anti-inflammatory drugs (NSAIDs) and COX-2 inhibitors for symptom control 5
• Prostaglandin therapy for leg pain and intermittent claudication 5
• Epidural injection and transforaminal injection for radicular symptoms 5
• The majority of patients with lumbar spondylosis and stenosis can be treated nonsurgically 5

Surgical Intervention

Operative treatment is indicated for moderate to severe CSM and is most effective in preventing disease progression. 2

Indications for Surgery

Cervical:

• Moderate to severe cervical spondylotic myelopathy 2
• Persistent pain despite conservative treatment 4
• Progressive neurologic deficit 4
• Severe neurologic deficits at presentation 4

Lumbar:

• Total incapacitation from spinal stenosis or spondylolisthesis 5
• Failed conservative management 3

Surgical Approaches

Cervical spine:

• Anterior cervical approaches are generally preferred, with good initial results in approximately 70% of patients 4
• Anterior surgery is beneficial for stenotic disease limited to a few segments or when correcting kyphotic deformity 2
• Posterior procedures (laminectomy) allow decompression of multiple segments when adequate posterior cord drift is attainable 2
• Long-term improvement occurs in 70-80% of patients with spondylotic radiculopathy 4
• Functional outcome declines with long-term follow-up in myelopathy cases 4

Lumbar spine:

• Current standards include discectomy, neural decompression, and instrumented spinal arthrodesis 3
• Treatment should be directed toward the specific nature and location of individual pathology 3

Important Clinical Pitfalls

• Do not attribute neurologic symptoms to imaging findings alone—consultation with a neurologist is advised to rule out other neurologic diseases, as imaging abnormalities may be asymptomatic 4
• Functional outcomes in CSM surgery decline with long-term follow-up, raising questions about how much surgical treatment affects natural disease course 4
• Distinct risks exist with both anterior and posterior cervical surgery and must be considered in decision-making 2
• For patients choosing conservative treatment for mild CSM, close clinical and radiographic follow-up is mandatory, with precautions for trauma-related neurologic sequelae 2