Herniation of part of the disc causing pressure on a nerve or the cauda equina. The terms ‘herniated disc’, ‘disc protrusion’ and ‘slipped disc’ mean essentially the same. The term ‘disc bulge’ is often used to describe some mild bulging of the disc into the lumbar canal. This is often seen in degeneration of the spine. Whether the disc is bulging or is herniated makes little difference to the treatment. This will depend on the patients symptoms. Most disc protrusions occur in the lower lumbar spine. If it occurs in the upper lumbar spine symptoms may be confused with other conditions or misinterpreted. The cause is usually degenerative (wear and tear) but can also follow trauma.
Most patients experience initially low back pain due to the rupture of the ring of disc (annulus). It is then followed by pain shooting down the leg (‘sciatica’), usually below the knee (lower lumbar disc protrusions). In disc protrusions of the upper lumbar spine the pain may only radiate to the thigh or into the knee. This can be associated with pins and needles and in some cases weakness of the leg or foot. In rare cases a disc protrusion can cause problems with the control of passing urine which requires immediate medical attention (cauda equina syndrome).
Permanent numbness or weakness in the leg/foot, cauda equina syndrome or neuropathic pain due to nerve damage.
Patients with a suspected disc protrusion should have an MRI scan unless the symptoms resolve quickly. There is no indication for plain x-rays or blood tests unless other causes are suspected (red flags). If a patient cannot have an MRI scan (e.g. cardiac pacemaker) a CT-scan or myelogram is indicated.