Does a fibronectin and aggrecan complex play a role in painful vertebral disks?

OBJECTIVE To determine the presence of a fibronectin-aggrecan complex (FAC) in the disk space of persons with chronic low back pain as relates to provocative diskography. DESIGN A single-center prospective consecutive case series. SETTING A single private practice setting. PATIENTS Thirty-seven patients with symptomatic degenerative disk disease of the cervical, thoracic, or lumbar spine undergoing provocative diskography to identify a source of pain. METHODS Diskographic lavage for analysis was simultaneously performed at each disk level injected during diskography. MAIN OUTCOME MEASURES Visual analog scale (VAS) pain scores, Pfirrmann magnetic resonance imaging grade, and biochemical analysis of disk material were statistically analyzed. RESULTS A total of 105 levels in 37 patients had a complete set of data (mean age 43.2 ± 11.9 years; 15 male/22 female). The FAC was present in 43 of 108 levels and in at least one level in 25 of 37 patients. The Pfirrmann magnetic resonance imaging grade did not differ between complex-positive and negative levels (P = .125), nor did the intraoperative VAS (IO-VAS) score for pain by level (P = .206). A significant but loose correlation was found between Pfirrmann grade and IO-VAS (R(2) = 0.4, P < .001), but no significant correlation was found between VAS or IO-VAS and complex concentration (R(2) = 0.08, P = .11 and R(2) = 0.003, P = .5). CONCLUSIONS The FAC was identified in some painful disks by diskography. There was no significant correlation between the Pfirrmann grade or pre/intraoperative pain scores during diskography and complex concentrations within the disk measured by disk lavage.