Disc narrowing after disc prolapse

This is a patient I reviewed yesterday. The first scan shows a disc prolapse sustained in 2006 when the patient was 27 years old. It is a little difficult to see as this is an old scan however the disc height at L5/S1 is preserved but there is a disc prolapse. Have a look at the scan two years later and again eight years later. The main thing to note is the narrowing has occurred at the L5/S1 level with no significant changes in height to above discs. The L4/5 disc has some loss of signal (dehydration) but the L5/S1 disc is significantly narrowed. Aging itself is not a precursor to disc narrowing and what is called degenerative changes. Changes to disc structure and loss of the hydraulic function of the disc results in increase impulse falling on the annular ligament that narrows over years and decades. In Clinical Anatomy of the Lumbar Spine written by Nik Bogduk (p 173, third edition) discusses how large scale postmortem studies have shown between the second and seventh decade there is nearly a 10% increase in disc height for most discs. Discs are washers absorbing pressure just like cartilage between our joints. The components of disc and cartilage are similar in a different arrangement. Both underlying joint bone surfaces and vertebral disc endplates develop new nerves in response to pressure if the cartilage or disc narrows. The determinants of pain are the extent of disc narrowing, impulse loading on the disc/vertebral complex and someones pain threshold often governed by migraine genetics and sympathetic nervous system tone. If we only focus on peripheral factors such as core strength, muscles and dysfunction we may be setting up patients for long term problems.