Objective To compare the clinical results of oblique lumbar interbody fusion (OLIF) and posterior lumbar interbody fusion (PLIF) in the treatment of adjacent segment degeneration（ASD） after lumbar fusion. Methods A total of 29 cases of adjacent segment degeneration after lumbar fusion who underwent surgery from July 2015 to December 2017 were followed up and retrospectively evaluated.Among these patients

13 cases underwent OLIF (OLIF group) while the other 16 cases underwent PLIF (PLIF group).The operative time

intraoperative blood loss

hospital stay

complications

VAS score

Oswestry dysfunction index (ODI)

intervertebral disc height (IFH)

intervertebral foramen height (IDH) and intervertebral foramen area (IFA) were compared between the two groups.Results The 29 patients were followed up for 12 to 36 months

with an average of (20±3.5) months.The operative time

intraoperative blood loss and hospital stay of the OLIF group were significantly lower than the PLIF group

and the differences were statistically significant (P<0.05).There were no statistically differences in VAS score

ODI

IFH

IDH

and IFA between the two groups （P>0.05）.There were 2 cases of intraoperative dural sac rupture and cerebrospinal fluid leakage in the PLIF group

and there were no serious complications in the OLIF group.The complications of the OLIF group were less than the PLIF group

which has statistically significant difference (P<0.05).Conclusion Both OLIF and PLIF have a satisfactory effect in the treatment of adjacent segment degeneration after lumbar fusion.OLIF has advantages of less traumatic

shorter operation time and higher safety

which conforms more to the concept of minimally invasive surgery.And the operation indications should be master strictly.