What are some common causes of low back pain?
Many acute cases (less than 3-6 months duration) are attributed to strains/sprains of the muscles or ligaments, and tend to be self-limited, improving over time. Medications such as anti-inflammatories and analgesics can be helpful with symptoms and pain, allowing the inflammation to calm down.
Facet Joints – Between adjacent vertebrae (back bones), there is a intervertebral disc and two facet joints. The facet joints can be a source of pain due to athritis (joint degeneration) and inflammation. Imaging abnormalities, such as seen on MRI, are diagnostically unreliable alone. However, facet blocks/injections of anesthetic and anti-inflammatory medication, done under fluoroscopic, or live x-ray, guidance, can provide both diagnostic information on the pain generator (source), as well as therapeutic pain improvement. If the facet joints are determined to be a significant pain generator, then the medial branch nerves or dorsal rami, which supply sensation of pain from the joints, can be denervated by radiofrequency ablation (RFA) or rhizotomy, which can provide longer duration of pain relief.
Sciatica – The sciatic nerve is a large nerve that runs down the back of the leg, which generally originates from the L4-S3 nerve roots. When a nerve root is irritated or inflamed in the low back, it can cause pain, weakness, and sensory abnormalities affecting the lower extremity. Also known as lumbar radiculopathy, the nerve roots is often being irritated or compressed by disc material or degenerative changes of the spine. Epidural steroid injections (ESI), under fluoroscopic or x-ray guidance, inject anesthetic and anti-inflammatory medications by the injured/damaged nerve root or disc, to reduce pain. Spinal stenosis is narrowing of the central spinal canal, which effects the spinal cord or nerves descending through the spine, and can be another cause of “sciatica”, with symptoms radiating into the legs, generally worse with standing and walking and relieved with sitting or bending forward. ESI’s can be helpful sometimes to reduce pain and symptoms.
Disc herniation/rupture/tear/degeneration – The intervertebral discs between vertebrate have pain sensing nerves, in the outer portion of the disc, and disc tears may be painful. The inner disc material leaking out of the disc can be irritating to the nerves causing inflammation, and can physically compress exiting or traversing nerves potentially causing pain, weakness and sensory abnormalities. ESI’s can be helpful sometimes to reduce symptoms.
Dr. Nara Pravat 