Low Back Pain and Leg Pain Flashcards
What is the critical factor in assessing patients with lower back pain?
Features of lumbosacral nerve root compression such as leg pain or focal signs of neural compression in lower limbs.
What causes sciatica?
Most commonly by lumbar disk prolapse Osteophytes Lumbar canal stenosis Spondylolisthesis Tumors are rare (cauda equina or pelvic)
What are the most common lumbar levels for disk prolapse?
L5/S1 (75%)
L4/L5 (20%)
Why is disc herniation usually in a posterolateral direction?
PLL (posterior longitudinal ligament) prevents direct posterior herniation.
What is the difference between a posteromedial prolapse vs lateral prolapse?
- Posteromedial causes compression of lumbar nerve root passing across the disc to enter the neural canal BELOW pedicle
- Posterolateral causes compression on nerve root passing beneath pedicle ABOVE prolapse
What is presentation of patient with sciatica?
- Obvious discomfort
- Lies tilted to side opposite of sciatica
- Affected hip/knee slightly flexed taking pressure off stretched nerve
- Pain worse with straining
- Pain radiating to buttocks, posterolateral calf and foot (S1) or dorsum of foot and great toe (L5)
- Pain along anterior thigh (L3)
- Pain along anterior leg/shin (L4)
- Check sphincter tone as large may cause cauda equina compression
Important PE in sciatica?
- Straight leg testing on affected side
- Head to toe neuro exam
- Look for muscle wasting
- For plantarflexion weakness ask to stand on tippy toes
- DTRS!
- Rectal exam
Segmental innervation of hip flexors, adductors, medial rotators?
L1, L2, L3
Segmental innervation of hip extensors, abductors, lateral rotators?
L5, S1
Segmental innervation of knee extensors?
L3, L4
Segmental innervation of knee flexors?
L5, S1
Segmental innervation of ankle dorsiflexors?
L4, L5
Segmental innervation of ankle plantarflexors?
S1, S2
Segmental innervation of foot invertors?
L5, S1
Segmental innervation of foot evertors?
L5, S1
Segmental innervation of intrinsic foot muscles?
S2, S3
Describe clinical features of L5/S1 prolapsed disc?
- Pain along posterior thigh with radiation to heel
- Weakness of plantar flexion
- Sensory loss in lateral foot
- Absent ankle jerk
Describe clinical features of L4/L5 prolapsed disc?
- Pain along posterior or posterolateral thigh with radiation with radiation to dorsum of foot and great toe.
- Paresthesia and numbness of dorsum of foot/great toe
- Reflex changes unlikely
Describe clinical features of L3/L4 prolapsed disc?
- Pain in anterior thigh
- Wasting of quads muscle
- weakness of quads function and dorsiflexion of foot
- Diminished sensation over anterior thigh, knee and medial aspect of lower leg
- Reduced knee jerk
Management of bulging disc vs. nucleus pulposus that has herniated out of disc space?
- bulging disk does well with conservative treatment
- nucleus pulposus herniation most likely need surgery
Describe important features of conservative treatment for disc herniation?
- should improve in 7-10 days (bed rest), with NSAIDs
- spinal manipulation is NOT recommended
- Resolution 2/2 to resorption of prolapsed disc material, edema of nerve decreasing and possible adaptation of pain fibres to pressure.
Investigations for low back pain?
- Lumbar spine XR (excludes spondylolisthesis, tumor)
- ESR (excludes systemic disease)
- (MRI if does not improve after conservative management and/or if see Red Flags!)
Indications for surgery re: low back pain?
- Pain (incapacitating despite bed rest, recurrent pain despite adequate relief with bed rest)
- Neurological deficit (significant weakness, increasing weakness)
- Central disk prolapse (bilateral sciatica, sphincter disturbance, diminished perineal sensation – EMERGENCY!)
Surgical options for disc prolapse?
- Typically laminectomy, occasionally disc prolapse excision.
- Bulging disk = conservative tx, sometimes percutaneous disectomy helpful
- Bulging nucleus pulposus = percutaneous disectomy not helpful
Prognosis following disc prolapse surgery?
- Correlated to accuracy of pre-operative clinical evaluation
- Good hx of sciatica
- Good signs of nerve root irritation
- Evidence of herniated disc
- Patient well motivated
- At surgery the nerve root is stretched by disc prolapse
- 10-15% recurrence of prolapse
Clinical presentation of lumbar stenosis?
- Pain radiating into legs, esp standing or walking
- Burning/achy quality
- Relieved with sitting, bending forward
- Similar to vascular claudication (must rule out!) pain when standing only = neurogenic claudication
Exam findings of lumbar stenosis?
- Sensory disturbance
- Maybe muscle wasting
- Check peripheral pulses
- Mostly Hx
Explain pathology of lumbar stenosis?
- combo of canal stenosis and degenerative path such spondylosis with hypertrophy of facet joints, ligamentum flavum, osteophyte formation = narrowing of canal and bulging disks
- most common L3/4, L4/L5
Management of lumbar stenosis?
- CT and MRI
- Doesn’t respond well to conservative treatment
- Surgical options: decompressive lumbar laminectomy over region of stenosis with decompression of lumbar theca and nerve roots
What is the presentation of low back pain without leg pain or signs of nerve root compression?
- acute, often following minor trauma
- chronic or recurrent
- usually due to soft tissue strain
- if severe, may have included fracture or disc herniation
- exam must exclude neuro sx
- xray to exclude fracture (if severe)
In cases where back pain is chronic or recurrent after minimal or trivial trauma what is common pathology?
- lumbar spondylosis
- spondylolisthesis
- degenerative disc disease
Uncommon low back pain without radicular signs includes:
- spinal tumors
- thoracic disc prolapse
- spinal abscess
- arteriovenous malformation
(also consider pancreatic disease, aortic aneurysm, renal disease i.e. infection, tumor)
What is spondylolisthesis?
Subluxation of vertebral body on another, usually L4 or L5.
What is spondylolysis?
Defect in pars interarticularis, leads to spondylolisthesis
Presenting features of spondylolisthesis?
- Back pain w/ leg pain
- “Tight” feeling in upper thighs
- Vertebral slippage may compress lumbar nerve roots in neural foramen
Treatment of spondylolisthesis?
- Conservative therapy with short periods of bed rest during exacerbations of discomfort, gentle mobilizing exercises, NSAIDs
- If still in pain, maybe lumbar brace
Indications for spondylolisthesis surgery?
- symptoms of lumbar stenosis
- clinical features of nerve root compression unrelieved by conservative therapy
- laminectomy to decompress nerve roots with spinal fusion
Surgical treatment of Spondylolisthesis by grade?
Type 1 = surgery not good
Type 2 = typically benefit from surgery
Type 3/4 = greatly benefit
