The impact of sagittal balance on low back pain in patients treated with zygoapophysial facet joint injection.

INTRODUCTION: Aim of the study was to evaluate the effectiveness of facet joints injections in lumbar facet syndrome correlating clinical results to the sagittal contour of the spine.

METHODS: Facet joints degree degeneration was evaluated using MRI according to Fujiwara classification. Sagittal contour of the spine was evaluated according to Roussouly classification. The clinical results were evaluated with visual analog scale (VAS) at regular intervals.

RESULTS: Twenty-eight (70 %) of the 40 patients had clinical symptoms improvement, 12 (30 %) showed no benefit. There was a statistical significant correlation between postoperative VAS value improvement and Roussouly spine type 1 and 3 (p = 0.003). The benefit was more durable in patients with grade 2 or 3 degeneration.

CONCLUSIONS: Facet joints injections have a more effective diagnostic than therapeutic value. The procedure could, however, give a temporary pain relief in cases with an overload of the facet joints due to lumbar hyperlordosis.