Background:

Controversy still exists regarding the optimal fusion technique for the treatment of unstable lumbar spondylolisthesis.

Objective:

To evaluate the safety and efficacy of modified facet joint fusion (MFF).

Methods:

A total of 491 patients with unstable lumbar spondylolisthesis who underwent MFF were retrospectively reviewed. Computed tomography was used to evaluate the fusion rate of MFF at 6- and 12-mo follow-up postoperatively. Clinical outcomes included visual analog scale pain scores for low back pain (VAS-LBP) and leg pain (VAS-LP), Japanese Orthopedic Association scores (JOA), and Oswestry Disability Index (ODI), all of which were obtained preoperatively and postoperatively at 1-, 3-, 6-, and 12-mo follow-up times. The clinical outcomes were determined to be excellent, good, fair, or poor according to the MacNab classification at the last follow-up time.

Results:

Of the 491 patients, the fusion rates at the 6-mo and 1-yr follow-up were 56.8% and 96.1%, respectively. Between baseline and 1-yr follow-up time, VAS-LP and VAS-LBP improved from 5.6 ± 0.9 to 0.4 ± 0.5 and 5.1 ± 1.2 to 1.5 ± 0.9, respectively (P < .001). JOA improved from 9.0 ± 2.0 to 27.7 ± 1.0, and ODI decreased from 64.0 ± 2.0 to 19 ± 1.0 (P < .001). At the final evaluation, 93.6% patients showed excellent or good results, and 3.2% showed fair results. There were no MFF technique-related complications.

Conclusion:

MFF technique achieved satisfactory clinical outcomes and fusion rate and appears to be a promising alternative fusion technique for the treatment of unstable lumbar spondylolisthesis.