Lumbar spinal stenosis is a condition characterized by the narrowing of the spinal canal in the lower back, which can lead to compression of the spinal cord and nerve roots. This narrowing can cause pain, numbness, and weakness in the legs.
Causes
- Degenerative Changes: The most common cause is age-related degeneration, including osteoarthritis and the formation of bone spurs.
- Herniated Discs: Discs that bulge or rupture into the spinal canal can cause stenosis.
- Thickened Ligaments: Ligaments within the spine can thicken and calcify over time, leading to stenosis.
- Spinal Injuries: Traumatic injuries can cause dislocations or fractures that result in spinal canal narrowing.
- Congenital Conditions: Some individuals are born with a naturally narrow spinal canal.
Pathophysiology
- Degenerative Disc Disease: As discs lose water content and height, they can bulge or herniate, reducing space in the spinal canal.
- Facet Joint Osteoarthritis: Degeneration of the facet joints can cause bone spurs to form, further narrowing the canal.
- Ligamentum Flavum Hypertrophy: The thickening of this ligament can encroach on the spinal canal.
- Central Canal Stenosis: Narrowing occurs within the central part of the spinal canal.
- Lateral Recess and Foramen Stenosis: Narrowing occurs where the nerve roots exit the spinal canal.
Symptoms
- Pain: Typically in the lower lumbar spine, buttocks and thighs, which may radiate to the legs and feet. Standing and walking may exacerbate the pain of spinal stenosis, while sitting and bending relieves discomfort. Some patients with spinal stenosis report that walking is more comfortable when leaning on a shopping cart, when the spine is flexed. Patients are comfortable climbing stairs up, but can not climb down because spine is extended and spinal canal is further narrowed, compressing the nerves.
- Numbness: In the buttocks, legs, or feet.
- Weakness: In the legs, leading to difficulties with walking and balance.
- Claudication: Pain and cramping in the legs when standing or walking, relieved by sitting or bending forward.
- Loss of Bladder or Bowel Control: In severe cases, this can indicate cauda equina syndrome, a medical emergency.
Treatment
Conservative Treatments
- Medications: NSAIDs, analgesics, and corticosteroid injections to reduce inflammation and pain.
- Physical Therapy: Exercises to strengthen muscles and improve flexibility, particularly cycling or treadmill walking, swimming with a side stroke may provide the benefits of activity without exacerbating symptoms.
- Activity Modification: Avoiding activities that exacerbate symptoms.
- Epidural Steroid Injections: To reduce inflammation and pain around the compressed nerves.
Surgical Interventions
- Laminectomy: Removal of part of the vertebrae (the lamina) to enlarge the spinal canal.
- Laminotomy: Partial removal of the lamina.
- Foraminotomy: Enlargement of the foramina to relieve nerve pressure.
- Spinal Fusion: Joining two or more vertebrae to provide stability, often done in conjunction with other procedures.
Interventions
- Alternative Therapies: Acupuncture, chiropractic care, and massage therapy can provide symptom relief for some patients.
- Assistive Devices: Canes or walkers can help improve mobility and stability.
- Lifestyle Changes: Weight management and smoking cessation can improve overall spinal health.
Surgical Considerations
Surgery is usually considered when there is instability because of spondylolisthesis or conservative treatments fail to provide relief or if there is significant neurological impairment. The choice of surgical procedure depends on the severity and location of the stenosis, as well as the patient’s overall health and preferences.
