Study design:

This was a retrospective cohort study.

Objective:

The objective of this study was to quantify the rates of complication following surgical treatment for symptomatic degenerative and isthmic spondylolisthesis and to examine the association between slip reduction and complication rates.

Summary of background data:

It is unclear if the degree of spondylolisthesis reduction during lumbar spine fusion in adults influences the rate of surgical complications.

Methods:

This is a retrospective cohort study of 1-level and 2-level adult fusion patients with degenerative or isthmic spondylolisthesis. The degree of reduction and complications were calculated, and complication rates between those with and without reduction were compared.

Results:

The surgical reduction was improved by 1 Meyerding grade in 56.5% of the 140 patients included in this analysis. Of those patients, 60% had a grade 1 spondylolisthesis. In addition, 62.5% of grade 2 slips had an improvement by 1 grade. Surgical reduction during lumbar fusion did not result in a higher rate of complications compared with in situ fusion.

Conclusions:

During 1-level or 2-level lumbar fusion for degenerative or isthmic spondylolisthesis, a 1-grade reduction of the slip was achieved in 56% of patients in this retrospective case series. Reduction of the spondylolisthesis was not associated with a higher rate of complication when compared with in situ fusion.

Level of evidence:

Level IV.