39 - Non-mechanical disorders of the lumbar spine: warning signs

The majority of lumbar spine syndromes encountered in clinical practice result from mechanical – activity-related – disorders. They can be classified into dural, ligamentous and stenotic syndromes. Lumbar syndromes, however, can also stem from non-mechanical – non-activity-related – disorders affecting the spine. These are: inflammatory diseases, both septic and rheumatological; tumours and infiltrative lesions; metabolic disorders; and acquired defects in the neural arch. Finally, pain in the lower back, groin and pelvic area can be referred from visceral organs (see online chapter Disorders of the thoracic cage and abdomen). Pain in buttocks, groin and limb, as the result of reference from the sacroiliac and hip joints, although ‘activity-related’, does not have a spinal origin and is discussed thoroughly in the chapters on the hip joint and sacroiliac joint. Although the occurrence of non-mechanical (non-activityrelated) disorders is rare, it is important to differentiate them as quickly as possible from mechanical activity-related lesions. This is never easy, because these disorders frequently mimic other, more specific lumbar lesions. Sometimes the diagnosis is made radiologically but very often this is of no help, especially in the early stages of an inflammatory or neoplastic disease. A thorough history and clinical examination are what will first draw attention to the possibility of a non-activityrelated disorder: the history may show an unusual localization or an atypical evolution of the pain; particular clinical signs may arouse suspicion. Most of all, however, it is the comparison between history and clinical examination, resulting in the existence of ‘unlikelihoods’, that focuses attention on serious spinal pathology such as vertebral fracture, malignancy, infection or inflammatory disease.