Effects of Concomitant Decompression Adjacent to a Posterior Lumbar Interbody Fusion Segment on Clinical and Radiologic Outcomes: Comparative Analysis 5 Years After Surgery.

Abstract

Retrospective cohort study. To examine the effects of concomitant decompression adjacent to the posterior lumbar interbody fusion (PLIF) segment on the clinical and radiological outcomes 5 years after surgery. Forty-five consecutive patients who had undergone L3/4 decompression with L4/5 PLIF for multilevel stenosis with degenerative spondylolisthesis (DS), and were followed for 5 years, were enrolled (group D). As a control group, 45 age-, sex- and preoperative disc height at L3/4-matched patients who had undergone L4/5 PLIF alone for L4/5DS were randomly selected (group A). Disc height, vertebral slippage, range of motion, posterior opening angle, segmental lordotic angle, presence of the intradiscal vacuum phenomenon (IVP) at the L3/4 level were measured on radiographs. Japanese Orthopaedic Association (JOA) score and the requirement for additional L3/4 surgery were evaluated. In terms of pre-/postoperative radiographic changes between the groups, significant differences were detected regarding disc height narrowing of ≥3 mm (group D 31%, group A 9%) and IVP (group D 33%, group A 11%). There were no significant differences in other radiological parameters. The recovery rate of the JOA score (group D 58%, group A 61%) and reoperation rate (group D 2.2%, group A 6.7%) were not significantly different between the groups. Concomitant decompression adjacent to the PLIF segment accelerated adjacent disc degeneration compared to PLIF alone, but it did not predispose to the development of instability 5 years after surgery. Moreover, the JOA score and reoperation rate were not significantly different between groups D and A.