Introduction: Controversy remains over the use of provocative discography in conjunction with computerized tomography (CT) to locate symptomatic intervertebral discs in patients with chronic low back pain (LBP). This study explores the relationship between discogenic pain and disc morphology using discography and CT, respectively, and investigates the outcome-based efficacy of this method in identifying surgical candidates for lumbar interbody fusion.
Methods: 43 consecutive patients with chronic refractory LBP underwent discography with subsequent CT on the injected discs; disc morphology and pain response were characterized. Concordant pain was defined as LBP of similar character and location with an intensity of 8/10 or greater. Fusion candidates were those who demonstrated positive level discography and concordant annular tears on CT at no more than 2 contiguous levels, and at least 1 negative control disc.
Results: Concordant pain (87 of 128 injected disc, 68.0%) occurred significantly more often in discs with annular tears (63 of 87 injected disc, 72.0%) than those without (24 of 87 injected disc, 28%, p<0.001). Painless discs were independent of annulus status (p=0.90). Volume of injected dye was significantly higher in patients with concordant pain (1.91±1.19 ml) than those without (1.58±1.05 ml) (p<0.05), and significantly higher in patients with annular tears (2.01±1.28 ml) than those without (1.25±0.54 ml) (p<0.001). Eighteen of the original 43 (42%) patients underwent surgery, mostly via minimally invasive transforaminal lumbar interbody fusion (MITLIF). Visual analog scale (VAS), Oswestry Disability Index (ODI), and Short Form-36 (SF-36) scores demonstrated significant improvements at 3, 6 and 12 months postoperative time points compared with preoperative baseline (median follow-up 18 months).
Conclusions: Lumbar discography with post-discography CT can be an effective method to evaluate patient with discogenic LBP refractory to non-operative treatments. Patients with one- or two-level high concordant pain scores with associated annular tears and negative control disc represent good surgical candidates for lumbar interbody fusion.
Patient Care: Improve the diagnosis and subsequent treatment of refractory discogenic back pain
Learning Objectives: 1. There is a close association between discogenic pain response and annulus fibrosus disruption based on discography and CT.
2. Discography in conjunction with CT helps identify symptomatic discs for lumbar fusion and produces favorable outcomes.