This study compared the surgical treatment results between posterior lumbar interbody fusion (PLIF) and posterolateral fusion (PLF) with pedicle screw fixation in degenerative lumbar spinal disorders.

In 45 cases of PLF (group I) and 45 cases of PLIF (group II), lumbar lordosis, segmental lordosis, bone union and complications were considered to be an evaluation criterion. Kim's functional evaluation scale was used for the clinical results.

The average lumbar lordosis in group I was 36.84±8.31 ° preoperatively, 40.58±7.61 ° postoperatively and 35.73±7.61 ° at the last follow up. On the other hand, the respective changes in the average lumbar lordosis were 31.53±7.09 °, 39.11±7.21 °, and 35.47±7.76 ° in group II. Definitive solid union was obtained in 41 cases in group I (91.1%) and 43 cases in group II (95.6%). The rate of complications was 24.4% (11 cases) in group I and 2.2% (6 cases) in group II, and a satisfactory functional outcome were obtained in 43 cases (95.6%) in group I and 41 cases (91.1%) in group II.

Both PLF and PLIF on short segment fusion provided satisfactory bone union and clinical results. In segmental lordosis, there were no significant differences between the two groups. However, PLIF was more effective in preventing lumbar lordosis and complications than PLF. A longer term follow up will be needed to evaluate the adjacent segmental degeneration and maintenance of the sagittal balance.