Mechanisms of chronicity?

Abstract

Most of us experience acute episodes of back pain. Clinical evaluation helps us segregate patients into those with simple backache, nerve root pain and possible serious spinal pathology. The vast majority are in the first group. The prognosis of simple backache is good, with most being better within a couple of weeks and 90% better within 6 weeks. However, a small proportion have persistent problems and it is these which require difficult management decisions and lead to the medical and societal costs of backache. This article focuses on the reasons why simple backache may fail to resolve and some patients develop chronic persistent problems. In this context, I will restrict myself to mechanical disorders and not deal with inflammatory conditions such as ankylosing spondylitis, metabolic bone disease or neoplasms. Some patients have persistent nociception, e.g. there may be a chronic herniated disc, a spondylolisthesis or spinal stenosis syndrome. There are specific and well identified clinical features enabling us to recognise these conditions. The vast majority have so-called non-specific back pain. They may show pain and tenderness over the facet joints or the sacroiliac joints. However, there is no clear evidence that pathology in