Single Intradiscal Administration of the Tumor Necrosis Factor-Alpha Inhibitor, Etanercept, for Patients with Discogenic Low Back Pain.

OBJECTIVE

To examine the analgesic effect of intradiscal administration of a tumor necrosis factor-αα (TNF-α) inhibitor in patients with discogenic low back pain (LBP).

DESIGN

Prospective, randomized study.

SETTING

Department of Orthopaedic Surgery, Chiba (Japan) University Hospital.

SUBJECTS

Seventy-seven patients diagnosed with discogenic LBP.

METHODS

Discogenic LBP patients were randomly assigned to the etanercept (n = 38; bupivacaine [2 mL] with etanercept [10 mg]) or control (n = 39; bupivacaine [2 mL]) groups. Patients received a single intradiscal injection. Numerical rating scale (NRS) scores for LBP at baseline, 1 day, and 1, 2, 4, and 8 weeks after the injection were recorded. The Oswestry disability index (ODI) scores at baseline and at 4 and 8 weeks after injection were evaluated. Postinjection complications were recorded and evaluated.

RESULTS

In the etanercept group, the NRS scores were significantly lower than in the control group at every time point after the injection for 8 weeks (P < 0.05). Similarly, 4 weeks after the injection, the ODI score was lower in the etanercept group than in the control group (P < 0.05). However, the ODI scores were not significantly different at 8 weeks. Complications were not observed.

CONCLUSIONS

Single intradiscal administration of a TNF-α inhibitor can alleviate intractable discogenic LBP for up to 8 weeks. TNF-α may be involved in discogenic pain pathogenesis. This procedure is a novel potential treatment; longer-term effectiveness trials are required in the future.