THE ROLE OF PROVOCATIVE DISCOGRAPHY IN TOTAL DISC REPLACEMENT SURGERY: WITH MINIMUM 2 YEAR FOLLOW-UP

Abstract

Introduction: The role of discography before lumbar fusion had been discussed in the literature. No study discussed its role before total lumbar disc replacement (TDR). Degenerate discs are not necessarily painful, even if they show Modic changes or HIZ. Moreover, discogenic pain might not be the predominant element in the patient’s symptoms and most of the back pain could be originating form other spinal structures. The aim of our prospective cohort study is to show whether or not provocative discography plays any significant role before TDR and to define that role.

Methods: Twenty patients (11 females and 9 males) had “Prodisc” TDR. Mean age = 38.5 years (range: 20–56). All patients had mechanical low back pain with degenerative disc disease diagnosed by MRI scan. 65% (N=13) had radicular pain as well. The mean duration of back pain = 66.9 months (range: 16–240). Pre-operative provocative discography was performed in all cases. The clinical outcome was assessed by comparing the preoperative SF36-v2, ODI and VAS scores’ means to the 3, 6, 12 and 24 months post-operative ones and also comparing the last follow up SF36-v2 scores with the, age and sex adjusted, normative data for the general UK population obtained from the Oxford Healthy Lifestyle Survey III. All patients were followed up for a minimum of 2 years.

Results: 90% (N=18) experienced a clinically significant improvement of their back pain (MCID for SF36-v2 scales=1SD, ODI=10 points and VAS=2 points). There has been a statistically significant improvement in the follow up outcome measures (P< 0.05) at 3, 6, 12 and 24 mths. SF 36-v2 scores of 15% of patients (N=3) reached or exceeded the normative values for the UK general population.

Conclusion: Provocative discography is an important diagnostic tool before TDR. It is the only dynamic method to diagnose discogenic pain and is indispensable to exclude the painless levels in cases of multilevel disc degeneration.