Lower Back Pain
What is it?
Lumbar disk herniation (LDH) is the protrusion of disk into the spinal canal in the lower back. Disks are the cartilage between the vertebral bodies that allow for movement of the spine.
Trauma is the most common identifiable cause of LDH; though most patients suffer the onset of LDH without any identifiable trauma, and simply “wake up with it”. LDH often presents with symptoms of back pain. Most patients with back pain do not have LDH, they may have a pulled muscle or joint arthritis. LDH can create pressure on the nerves in the spine and can cause characteristic pain syndromes. Pain, numbness, tingling, burning, and weakness often are bundled together and radiate down from the back to the leg, also known as sciatica. Significant spinal canal compromise can result in bowel and bladder incontinence and paralysis (total or partial).
Characteristic findings of nerve root compression (causing sensory, reflex and motor changes) can occur with LDH at different levels of the back. At L3-4, symptoms involve the anterior thigh area and weakness occurs with knee extension. At L4-5, the anterior shin and top of the foot are affected with weakness lifting the foot up. At L5-S1, the calf and bottom of the foot are affected with weakness in pushing the foot down.
Magnetic resonance imaging (MRI) is the preferred study and should be a high quality lumbar spine study. The quality of lumbar MRI’s can vary between imaging centers and is usually less sharp with open MRI’s. Computed tomography (CT) with myelography can be done in special circumstances. Plain X-rays and bone scans are not useful in diagnosing LDH, but may be done as part of the workup of lumbar pain.
Most patients with LDH will improve with medical management, typically within the first 6 weeks after the onset of symptoms.
Step 1: Pain relievers, muscle relaxers, and possibly oral steroids (Medrol Dosepak) coupled with bed rest or reduced level of activity.
Step 2: Physical therapy which includes stretching exercises, heat, massage, and ultrasound. Patients need to determine the modality that works best for them. Each session provides short term benefit and ultimately should also be done at home.
Step 3: Pain management including epidural steroid injections (ESI). ESI is an injection of medication directly into the spinal canal. An ESI typically provides benefit lasting one month and can give lasting relief for those patients who are not surgical candidates.
Surgical Therapy Indicated for patients who do not respond to medical management, have large disk herniations, severe symptoms, are unlikely to respond to further non-surgical treatment, and/or have neurologic loss of function. An opening in the spine is performed through the back and is called a laminectomy. The disk herniation is removed freeing the nerve. The disk is still preserved and continues to function after recovery.
Outcome of Surgery
The goal of surgery is to preserve neurologic function, and give the best chance for pain reduction and neural recovery. This is most likely if nerve root compression is not allowed to persist for very long. The overall chance of a complication is very small in a healthy patient. Patients must balance the risk of surgery with the risk of permanent injury from the disk herniation. Surgery is usually very well tolerated. Most patients are up walking shortly after the surgery and go home the next morning. Long term outcome from surgery is generally excellent with very high satisfaction rates.