Abstract
One of the interesting aspects of spinal pathology having an important bearing on the treatment of backache is that the spine acts as an integrated whole and that damage sustained by one part frequently injures other structures in the spinal column. Thus disc degeneration may be associated with an extrusion of nuclear material; it may initiate degenerative changes in the posterior joints; it may predispose to tears of the posterior spinal ligaments; or it may give rise eventually to all of these lesions, any one of which may produce backache with or without sciatica. The sciatica may be referred pain or may be produced by nerve root pressure. Nerve root pressure in such instances is commonly due to an extrusion of nuclear material, but it may also be due to pressure on the nerve root within the foramen by a "squashed" disc or by a subluxated posterior joint.
Radiographs are of great value in the diagnosis of disc degeneration and they are of greater value in the assessment of the secondary effects that have taken place. With the use of bending films evidence of early degenerative changes may be obtained, tears of the supraspinous ligament can be detected, and abnormal movements of the posterior joints can be seen. Careful study of the antero-posterior and lateral projections will reveal evidence of subluxation of the posterior joints, chip fractures and degenerative arthritis in the zygapophysial articulations, and will clearly demonstrate overriding of the facets.
The investigation of subjective phenomena, such as backache, is fraught with many difficulties and it must be preceded by an investigation of the anatomy of the part and the anatomical variations, the normal and abnormal physiology and the pathological lesions that occur. Many of these changes of course may have no clinical significance, but it is only when armed with the knowledge of what may occur that we can tackle the problem of low back pain on a logical basis.
