Lumbar radiculopathy is also known as sciatica. This is a general term used to describe the pain or sensation felt by a person when a nerve in the lower back has become pinched and/or irritated. It typically causes pain in the lower back as well as the lower extremity (buttock and leg). Most commonly, one lower extremity is affected. The pain is described by most as a 'electrical shock' or 'lightning bolt' sensation. Some people do not find the sensation painful, but a feeling of 'pins and needles', a numbness known as a paresthesia.
Occasionally someone may have weakness in their lower extremity because the nerve is severely irritated and no longer working properly. However, this is rare and usually takes weeks/months to develop. Most people who have sciatica may have a hard time walking or doing activities because of pain, but the nerve is still working. Very rarely, people can have bowel or bladder problems from problems with the nerves in the lower back becoming very irritated or pinched. Again, this is very are but should be treated as soon as possible.
Sciatica can occur in younger adults (18-50 years old) as well as older adults (>60 years of age). It is usually not seen in children under the age of 18. In younger people, it is usually due to a lumbar disc herniation, or a herniated disc.
The discs serve as a cushion or 'shock absorber' between the individual bones of the lower back, known as the lumbar vertebra. The disc has a rubber-like outer structure (annulus fibrosis) and an inner cushion or jelly (known as the nucleus pulposus). When that inner jelly leaks out from the inside of the disc (usually due to aging and/or some movement or action), the jelly can push on the nerve, thus compressing it and causing abnormal sensations or pain. Also, the jelly's properties are very similar to bleach, and thus the nerve gets irritated and becomes swollen. If there is not enough room for the nerve and it is now swollen and compressed by the jelly, the nerve will not function normally, producing abnormal sensations, pain, and even weakness of the lower extremity.
In older adults, the lumbar radiculopathy, or sciatica, is usually also due to nerve pinching and irritation (which causes nerve swelling). However, in this case it is commonly from bone spurs (osteophytes) that have accumulated from wear and tear (degenerative arthritis) over the course of a person's lifetime.
The bones and discs in the lower back are moving parts and - like all moving parts - there is accumulation of wear and tear over time. As a result of the disc wearing out and not keeping its cushioning ability as people get older, the bones see more wear and tear and this causes the formation of bone spurs. Think of bone spurs on bone kind of like calluses on a person's hands. When one is working with their hands a lot, they will get more calluses as a result of the body trying to accommodate that extra stress. Very similarly, osteophytes accumulate on the spine as a result of wear and tear (degenerative arthritis). If one of these bone spurs just happens to tickle a nerve, it can produce the paresthesias, pain, and weakness that is seen in sciatica.
Regardless of the age of the patient, a trained spine physician can diagnose the condition of lumbar radiculopathy, confirm the diagnosis with imaging studies if needed, and use a variety of non-operative treatments to help alleviate the discomfort/pain a person is experiencing. These treatments include: oral medications, physical therapy, epidural injections, and even just observation for a period of time. Surgery is reserved for special situations and if all other treatments have failed.
The details of the surgery needed to treat the condition varies in the younger and the older patient, but both are generally minimally invasive and done as an outpatient. In the older patients, the bone spurs are removed and more room is created for the nerve. This procedure is called a microscopic foraminotomy. In the younger patient, the herniated disc fragment/jelly is also removed to create more room for the nerve, and this procedure is called a microscopic discectomy.
Please discuss any further questions about your specific situation with a fellowship-trained orthopedic spine surgeon.