Exploration of the use of biomarkers to monitor recovery after surgery for lumbar disc herniation: a prospective cohort study.

Objective assessment of damage to intervertebral discs is complex. The response to damage is characterized by increased collagen metabolism, which can be monitored by the serum markers PICP for type I synthesis and CTx for type I collagen degradation. In a cohort of 67 patients who underwent surgery for lumbar disc herniation, PICP and CTx were measured and ratings were made of back pain, leg pain, and functional disability, before and after the operation. In the 6 weeks following surgery, concentrations of PICP increased, concentrations of CTx decreased, and the ratio between PICP and CTx increased. Back pain and functional disability improved, but the scores were not significantly associated with the marker concentrations. The changes in serum markers most likely reflect tissue healing. However, these markers are not yet ready for clinical use.