Outcome of posterior lumbar interbody fusion versus posterolateral fusion in lumbar degenerative disease

Between March 2003 and September 2007, 170 consecutive patients with lumbar degenerative disease were studied retrospectively. Eighty patients underwent posterior lumbar interbody fusion (PLIF group) with pedicle screw (PS) fixation, and 82 patients underwent posterolateral fusion (PLF group) with PS fixation. Eight patients were lost to follow-up. The minimum follow-up period in each group was 2.0 years. The mean follow-up period for the PLIF group was 3.6 years, and for the PLF group, the mean follow-up was 3.4 years: there was no significant difference between the two groups for length of follow-up. The Pain Index (PI) improved from 66 to 27 in the PLF group (p < 0.001) and from 69 to 29 in the PLIF group (p < 0.001), but there was no significant difference between the two groups (p > 0.05). In the PLF group, the preoperative mean Oswestry Disability Index (ODI) score was 34.5, which reduced to 14.2 at the final follow-up. In the PLIF group, the mean preoperative ODI was 36.4, which reduced to 16.2 at the final follow-up. There was no significant statistical difference between the two groups for ODI (p > 0.05). Eighty-eight percent (n = 72) of patients in the PLF group and 91% (n = 73) in the PLIF group had radiologically confirmed union, with no significant difference in fusion percentage between the two groups (p > 0.05). Twenty-two of 162 patients (14%) underwent a second operation: 18 (22%) in the PLF group and four (5%) patients in the PLIF group (p < 0.001). The clinical and functional outcomes in both groups were similar, and no significant difference was found in the parameters tested. Both surgical procedures were effective, but patients in the PLF group showed more complications related to hardware biomechanics than patients in the PLIF group (p < 0.001).