Objective: To explore the effect of facet joint degeneration in adjacent segments on the incidence of adjacent segment disease (ASD) after lumbar fusion and fixation.
Methods: A retrospective analysis was performed on 138 patients who underwent L5S1 posterior lumbar interbody fusion (PLIF) from June 2016 to June 2019. Patients were divided into a degeneration group (68 cases) and a non-degenerative group (70 cases) based on the presence or absence of L4,5 facet joint degeneration before surgery (graded using the Weishaupt standard). Age, gender, body mass index (BMI), follow-up time, and preoperative L4,5 intervertebral disc degeneration (graded using the Pfirrmann standard) were collected for both groups. Clinical outcomes were evaluated using the visual analogue scale (VAS) and Oswestry disability index (ODI) at 1 and 3 months after surgery. The incidence and time of ASD after surgery were analyzed.
Results: There were no significant differences between the two groups in age, gender, BMI, follow-up time, or preoperative L4,5 intervertebral disc degeneration. Both groups showed significant improvement in VAS and ODI at 1 and 3 months after surgery (P<0.001), with no significant difference between the groups(P>0.05). However, there was a statistically significant difference in the incidence and timing of ASD between the groups (P<0.05). The degeneration group had 2 cases of ASD in gradeⅠdegeneration, 4 cases of ASD in gradeⅡdegeneration, and 7 cases of ASD in grade Ⅲ degeneration. There was a statistically significant difference between the number of patients with grade Ⅲ degeneration and those with gradesⅠandⅡASD (P<0.0167, Bonferroni correction).
Conclusion: Preoperative degeneration of adjacent articular processes will increase the risk of ASD after lumbar fusion fixation, whereas gradeⅢ degeneration will further increase the risk.
Keywords: Adjacent segment disease; Facet joint degeneration; Postoperative complications; Spinal fusion.