Lumbar Spinal Stenosis

Chronic degenerative condition (esp Osteoarthritis)
1. See risk factors below for associated conditions
2. Most commonly associated with Osteoarthritis
3. Lumbar degenerative disc disease often precedes Lumbar Spinal Stenosis
  1. Lumbar Vertebral disks collapse and destabilize the anterior Vertebral Column
    1. Weight is offset posteriorly onto facet joints, interspinous ligament, and ligamentum flavum
  2. Facet joints hypertrophy and osteophytes form
    1. Narrows the central canal and neuroforaminal canals
  3. Degenerative Spondylolisthesis
    1. Further contributes to spinal canal stenosis
Degenerative changes contributing to Lumbar Spinal Stenosis
1. Facet joint hypertrophy
2. Ligamentum flavum hypertrophy
3. Vertebral degeneration
4. Intervertebral Herniated disc
5. Spondylolisthesis
Results in narrowed spaces enclosing spinal neurovascular structures
1. Results in the Pseudoclaudication (buttock and Lower Extremity Pain worse with walking, standing, extension)
Images

Characteristics
1. Leg Fatigue (dullness) or Leg Weakness
2. Leg numbness, tingling or Paresthesias
3. Bilateral Leg Pain (burning or cramping)
  1. May involve buttocks, groin and anterior thigh
  2. May spread distally into posterior lower legs and feet
  3. May be associated with a sense of balance loss (sensitive marker for Lumbar Stenosis)
Provocative
1. Worse with walking or prolonged standing
2. Provoked by lying prone or extending Lumbar Spine
3. Not provoked by Bicycle riding
Palliative
1. Promptly relieved with sitting or bending forward
Severe symptoms: Cauda Equina Syndrome
1. See Cauda Equina Syndrome
2. Always ask about bowel and Bladder dysfunction, saddle Anesthesia and Foot Drop

Start with complete Neurologic Exam (often normal)
Perform brief ambulation to elicit leg symptoms
1. Observe for painful ambulation
2. Observe for wide based gait
3. Perform Romberg Test
Immediately repeat Neurologic Exam after walking
1. Lower extremity Sensory Exam changes
2. Lower extremity Motor Exam changes
Other provocative measures
1. Lumbar Spine extension often results in thigh pain
2. Spine is typically NON-tender to palpation
Evaluation to exclude other causes
1. Abdominal exam (evaluate for referred pain)
2. Hip Range of Motion (esp. rotation)
  1. Evaluate for hip disorder with referred pain
3. Lower extremity vascular exam (distal pulses)
  1. Rule-out Vascular Claudication cause
  2. Perform Ankle-Brachial Index if suspicion for Claudication

See Differential Diagnosis of Low Back Pain
Vascular
1. Vascular Claudication
2. Chronic Exertional Compartment Syndrome
Neurologic
1. Large Central DIsc Herniation
2. Lumbar nerve root impingement (typically unilateral)
3. Piriformis Syndrome
4. Peripheral Neuropathy
Musculoskeletal Disorders
1. Spondylolisthesis
  1. Degenerative lumbar Vertebra subluxation (L4-5)
2. Lumbar Spine Trauma or Vertebral Fracture
3. Sacroiliac Joint Dysfunction
4. Muscle Strains (e.g. hamstrings, quadriceps, hip adductor or abductors)
5. Hip Joint disorder
6. Myofascial Pain
7. Trochanteric Bursitis
Mass Lesions of Spine
1. Spine Metastases with nerve compression
2. Conus Medullaris
3. Cauda equina neoplasm
4. Benign cystic spinal lesions
  1. Neurofibromatosis
  2. Ependymoma
  3. Hemangioblastoma
  4. Dermoid
  5. Epidermoid
  6. Lipoma
Infectious or Inflammatory Conditions
1. Epidural Abscess
2. Inflammatory arachnoiditis
Referred Pain (Abdomen and Pelvis)
1. Gynecologic (e.g. Uterine Fibroids or Ovarian Cysts)
2. Inflammatory Bowel Disease (e.g. Crohn Disease, Ulcerative Colitis)
3. Urologic (e.g. Pyelonephritis or Ureteral Stone)
4. Vascular (e.g. Abdominal Aortic Aneurysm)

L-Spine MRI findings (preferred)
1. Loss of epidural fat (T1 weighted images)
2. Loss of CSF signal at dural sac (T2 weighted images)
3. Degenerative disc disease
L-Spine CT Myelogram (if MRI contraindicated)
1. Classic "Cloverleaf" or "Trefoil" canal appearance
L-Spine XRay alternative diagnosis findings
1. Degenerative spine changes
2. Occult Spina bifida
3. Spondylolisthesis