The most common cause for lower back pain is disc degeneration and wear and tear which happens because the disc changes gradually due to micro-trauma and becomes dehydrated which makes it vulnerable to prolapse or bul. The lumbar intervertebral disc which works as a shock absorber and provides a cushioning effect for the spine becomes less effective.
Disc prolapse is a condition when part of the disc protrudes but without rupturing the capsule and it causes compression/pinching or irritation of the nerve roots which can cause back and leg pain. The disc extrusion in which the fragment breaks the external capsule comes out and potentially can compress one or more nerve roots. Therefore the majority of the time back pain is a mechanical back pain due to wear and tear and the facet joint arthritis. The leg pain or numbness, pins and needles are usually due to the disc prolapsed compressing or irritating the nerve roots. Therefore a prolapse disc, herniated disc, sequestrated disc, or bulging disc is more or less the same thing but varies with the extent of compression of nerve root or roots.
Investigation
The most common and gold standard investigation is a MRI scan of the lumbar sacral spine, which gives you most of the relevant information that you need to manage this condition. However sometimes a CT scan is also done for specific reasons or when someone cannot have a MRI scan due to a number of reasons.
Possible treatment
Most of the time the symptoms of back pain and leg pain subsides depending upon the severity of the compression of the nerve root. Usually anti-inflammatory, muscle relaxant and other painkillers potentially alleviate this acute pain if there are no neurological symptoms.
Physiotherapy is another important aspect of the treatment and it helps to build the core muscles and can be effective.
If the symptoms are not responding to physiotherapy and painkillers then spinal injections potentially can be very helpful. The steroid injections of facet joint are usually helpful for back pain and an epidural is usually helpful for leg pain. However sometimes you may need both facet joint injection and epidural and depending on other factors including the MRI scan finding and symptoms.
The spinal surgery is recommended if non-surgical treatment options do not alleviate the symptoms. Sometimes surgery is needed urgently if it is causing weakness of legs or sphincter problem. The purpose of surgery is to remove the part of the disc which pinching nerve to decompress the nerve root, which alleviates the symptoms.
The most common operation for this condition is called microdiscectomy, which is minimally invasive procedure. The old fashioned laminectomy is rarely needed nowadays but in some cases a laminectomy and interlaminar decompression is also required.
