degenerative disc disease

Question 1

what is degenerative disc disease?

Answer 1

refers to the natural deterioration of the intervertebral disc structure, such that they become progressively weak and begin to collapse

Question 2

what factors precipitate damage to the intervertebral discs?

Answer 2

• Progressive dehydration of the nucleus pulposus
• Daily activities causing tears in the annulus fibrosis
• Injuries or pathology resulting in instability including mechanical insults (e.g spinal fractures), iatrogenic injuries (e.g spinal surgery), or systemic metabolic processes (e.g osteoporosis)

Question 3

what is the cascade of changes seen in degenerative disc disease?

Answer 3

1) dysfunction - outer annular tears, separation of endplate, cartilage destruction and facet synovial reaction
2) instability - disc resorption and loss of disc space height, and facet capsular laxity can lead to subluxation and spondylolisthesis
3) restabilisation - degenerative changes lead to osteophyte formation and canal stenosis

Question 4

what are the clinical features in degenerative disc disease?

Answer 4

• depend on region and severity of disease
• local spinal tenderness
• contracted paraspinal muscles
• painful extension of back and neck
• if degeneration causes instability, pain may be more severe and include radicular leg pain or paraesthesia
• further disease progression may demonstrate signs of worsening muscle tenderness, stiffness, reduced ROM and scoliosis

Question 5

what is Lasègues test?

Answer 5

aka straight eg raise, used to asses for disc herniation in patients with lumbago

patient lies down on back and examiner lifts leg with straight knee

positive sign if when pain is elicited during leg raise with/without ankle dorsiflexion or cervical spine flexion

Question 6

what are the differentials for back pain?

Answer 6

• cauda equina
• infection e.g discitis
• ## malignancy

Question 7

when should imaging be warranted?

Answer 7

• Red flags present
• Radiculopathy with pain for more than 6 weeks
• Evidence of a spinal cord compression
• Imaging would significantly alter management

Question 8

when warranted, what is the imaging of choice for suspected degenerative disc disease?

Answer 8

MRI spine

Question 9

what is the management for DDD?

Answer 9

• highly variable and patient dependant
• pain relief
• encourage mobility within patient limits for acute lower back pain
• physiotherapy
• emergency intervention only in cauda equina
• if persists beyond 3 months, referral to pain clinic