One of the characteristics of a lumbar inter-vertebral disc is the fact that it is a spinal shock absorber. That is to say, it absorbs the shocks of mechanical strain on the spine through typical everyday movement such as lifting, shifting, stooping and bending. As a disc ages, and for reasons we do not fully understand, the cushioning effects are lost and the disc can become painful. It is thought that the disc perhaps tears within its structure, allowing scar tissue to grow into it. This scar tissue contains noxious nerve endings which give an appreciation of pain which was not previously present. The disc wall can tear allowing noxious substance from disc degeneration to occasionally squirt into the spinal canal creating episodic inflammation. This situation can also occur if a disc collapses prematurely so that the supporting ligaments and muscles of the spine have not taken up the slack leading to uncontrolled and often painful movement.
The overriding treatment for spinal instability is physical therapy. Our first response is to build up the stabilising muscles around the spine to restrain a damaged disc, preventing abnormal movement causing severe episodic pain. This is described as core stabilisation. This treatment involves building up both the abdominal muscles and the back muscles to splint the spine and develop a “muscle corset” to allow controlled spinal movement without pain. Muscles are built up using Pilates techniques and the use of the fitball. In general exercises should be low impact. This spinal rehabilitation takes months and is therefore not a rapid and immediate cure. During this process pain control and anti-inflammatories must be taken to allow a high level of exercise. Exercise can also be supplemented by pain control via injection (be that facet joint blocks or caudal epidurals) to control inflammation whilst the exercise program continues. This often requires a number of specialist experts in rehabilitation.
Surgical solutions are only employed on prolonged failure of non-operative treatment in the face of increasing disability of the patient. The surgical options include spinal stabilisation by fusion, stabilisation via non-fusion techniques or disc replacement. Occasionally the localised disc bulge can be decompressed by a percutaneous discectomy, although the success rates of this technique for back pain are often not high. Non fusion techniques such as Dynesis or Wallis ligament are preferred in young people or in situations where there is no bony or major structural deficit.