Biomarkers of skeletal turnover, such as the synthesis and degradation of
extracellular matrix molecules in specific tissues, offer the opportunity to
gain new insights into spinal pathology and treatment. The creation, use, and
interpretation of these analytical body-fluid measures of process (rather than
outcome) require a clear understanding of the nature of the molecules and
events being measured. This review provides examples of how protein and
carbohydrate assays of biomarkers can be used to measure the contribution from
the intervertebral discs and vertebrae of the spine. With regard to spinal
degeneration and ankylosing spondylitis, these investigations are providing
important new information, in weeks rather than years, on the response of
patients to treatment.