RESUMEN
AIM OF THE STUDY: Degenerative changes of the motion segments are accompanied by an increased vascularization of the endplates. Nerve elements have been demonstrated in the environment of the endplate vessels, which might play a role in pressure related pain sensation. In order to investigate this theory we compared and correlated the extent of memory pain as determined by discography with the amount of vascularization in the endplates on histological examination. METHOD: Discography was performed in 32 Patients (21 female, 11 male), who underwent spinal fusion. The extent of pain sensation was determined on a self reported visual analogue scale ranging from 0-10 Points. Bone chips from the anterior vertebral endplates were obtained during surgery. Decalcified paraffin-embedded samples were then immunostained with the vascular endothelial marker CD 34. The quantification of endothelium as part of the whole cross section area was performed by means of a computerized optical method. RESULTS: The extent of the pain sensation during discography ranged from 0-9 points on the VAS (average: 5.3 points, SD 3.1). On the histological quantification the total endothelial area per observed field varied from 0.04 to 7.39 % (average: 2.19 %, SD 1.62). The comparison of the pain extent on discography and the vascularization of the endplate resulted in a correlation coefficient after Spearman of rho = + 0.64 (p=0.0006). CONCLUSION: The extent of vascularization in the degenerated endplates of a motion segment shows a moderate correlation with the self reported VAS scores after discography. Further investigations will have to clarify, whether neurogenic structures originating from vascular endothelium yield a better correlation to discogenic pain.