The effect of lumbar facet joint injection levels on spinopelvic parameters and functional outcome

Low back pain is a very common musculoskeletal complaint that impacts patients' quality of life in numerous ways. Facet joint injection is a widely used spinal intervention to relieve back pain. Effects of facet joint injection on spinopelvic parameters and the relationship between injection levels and spinopelvic parameter changes have not been evaluated before.

To compare spinopelvic parameters before and after injections at different levels, and to evaluate the correlation between these changes and functional outcome.

144 patients were included in the study and retrospectively grouped by injection level: Group 1 (n= 72), L4-L5 and L5-S1, and group 2 (n= 72), L1-L2, L2-L3, L3-L4, L4-L5 and L5-S1. Pre- and post-injection Oswestry Disability Index (ODI), sacral slope, pelvic tilt, pelvic incidence, and intervertebral angles between T12 and S1 were compared. The correlation between ODI and radiographic parameter changes was evaluated.

The pre- to post-injection ODI change was significantly lower in group 2 (p= 0.010). There was no significant difference between the groups in terms of pre- and post-injection spinopelvic parameters before and after injection (p> 0.05) except pelvic tilt (p= 0.001 and p= 0.007, respectively). There was a significant moderate positive correlation between the change in the ODI value and the change in pelvic tilt (P= 0.012, r= 0.581).

Multilevel lumbar facet injections are clinically more effective than only two-level lower level lumbar injections. Pelvic tilt changes positively correlate with the ODI score changes.