Tonight I attended a very interesting tutorial on discal injuries and how they would present. This tutorial was voluntarily and straight after clinic given by one of our clinic tutors.
I was very happy that I had heard that this was one tonight as I am still struggeling how to differentiate between discal and facetal presentations, so therefore pleased to attend a lecture from a very experienced osteopath. 
The first topic we covered were questions which are applicable to ask a patient considering a synovial joint. 
The three major points we always need to keep in mind when taking the case history are:
1. Position which is relevant for weight-bearing 
(on=standing, sitting; off=lying, bathing)
2. Action which is relevant to implicate different leverages
(specific provocative movements; repeated action)
3. Reaction which covers the timing and metabolism
(hydration, dehydration).
Interestingly and I had not known this before a lumbar spine disc of a 'normal' ( balanced spine carries about 30% of forces on standing while the other 70% are 'carried' by the facet joints. However this applies for the optimal weight transferring spine!!.. to consider that probably anybody has a perfect spine!!?
If we try to differentiate between a muscular tear and other tissues, muscles would immediately respond while the later have a slower metabolism rate. For instance does it take a disc up to 48 hours to respond but also does this reaction time depend on the hydration of the individual disc. Spondylosis (disc degeneration) is accompanied with altered permeability of the discal structure therefore a patient is likely to complain to wake up at night, to be stiff and tight in the morning and symptoms of stiffness subside after approx. 20min of walking. 
Question for our DD (Differential diagnosis) focusing onn weight bearing should include:
  • positions 'off' weight bearing
  • positions 'on' weight bearing 
  • weight bearing +action flexion
  • weight bearing + action extension
Sitting for instance has always an element of flexion, so the anterior part of the disc will be compressed, while on standing the forces going through the disc/spinal segment are shared with the lower extremity. Quit a view little details I learned tonight!! I will share some more here.. The spinal posterior longitudinal ligament is fused with the annular fibres of the disc. 

Question for our DD considering time should include:
  • weight-bearing time
  • weight-bearing time+reaction time
  • reaction time
  • off-weight bearing+reaction time

Then we discussed the importance of the history of similar episodes and traumatic impacts our patients might have had experienced in the past. For instance would a damage to the growth plate or vertebral endplate be a precipitating factor for spondylosis. The vertebral endplate (approx. 1mm) is the main source for nutrition for the disc and appears after the ossification phase of the vertebrae. 


Lastly it is necessary to consider the aetiologies of the mechanism of an injury. This includes bio-mechanical factors as:  1. weight bearing, 2. flexion/extension, 3. torsion. 


A disc herniation has actually the best recovery prognosis as phagocytosis allows the extruded material to be absorbed/metabolised. The last point tonight which was raised was theat we can observe on our evaluation where the actual disc herniation/protrusion is present even if the patient is asymptomatic. A so called 'wiggle' movement, an adventitious movement observable on active axial flexion of the spine. The start and end range of movement (EROM) would be normal however on the levels with possible mild disc herniation 'the wiggle' around this segment is observable.
I really appreciated this tutorial tonight and look forward to learn more about the treatment modalities of disc injuries!!!