The lumbar discs are the cushioning between adjacent lumbar vertebral bones. They are composed of a softer inner loose network of collagen maintained in position by an outer layer of more densely connected fibers. A herniation may occur during a traumatic, or a lifting and twisting injury of the back thus allowing disc material to produce pressure on a nerve root. At the L4-5 level, pressure on a nerve root may cause pain in the back with associated pain in the leg with or without loss of muscle function or sensation depending upon the severity of the herniation.
A majority of people with disc herniation symptoms will improve with conservative treatment and not require surgery and the pathology will resolve radiographically in approximately 60% of patients who then have no further compression of the nerve root. When pain continues despite decompression, it is from the failure of the nerve to fully recover. Continued pain is best treated with therapy, medications, lumbar cortisone injections, and referral to pain management specialists. Surgery is performed on those who remain symptomatic from continued compression of a nerve as documented by a diagnostic study such as MRI scanning or post myelographic CT scanning.