Effect of the Posterior Ligament Complex on the Adjacent Segment Degeneration after Posterior Lumbar Interbody Fusion

Abstract：Objective To explore the effect of the posterior ligament complex on the adjacent segment degeneration after posterior lumbar interbody fusion.Methods FromJ anuary 2000 to January 2010,60 patients were treated by posterior lumbar interbody fusion(PLIF)and internal fixation with posterior lumbar interbody fusion(L4~5). Group A(30 cases):the PLIF group(30 cases)underwent PLIF with posterior ligament complex conserved,B group( cases):PLIF with posterior ligament complex resected. We compared the JOA score,improve rate before and after surgery of the two groups. At the end of the opera-tion,the height of lumbar 3 ~4 intervertebral disc and the dynamic angle of lumbar intervertebral space were measured and compared with the lumbar 3~4 intervertebral disc. Before and at the end of the follow-up,the 3~4 lumbar intervertebral disc wasgradedaccordingtoPfirrmanngrade.Results There was significant difference in JOA score before and after operation(P<0. 05)in both group. There was no significant difference between the two groups(P>0. 05). A group had 9 patients with lumbar 3/4 segment of the ASD,B group had 17 cases of lumbar 3~4 segment ASD. Among them,each groups had 2 cases of patients with symptoms of ASD. There were not difference in 3~4 lumbar intervertebral disc height,intervertebral space dy-namic angle ,waist 3 ~ 4 vertebral slip distance . But at the time of last follow - up significant difference could be found( P <0. 05). At the end of the follow-up A group had 6 cases of Pfirrmann grade 1,22 cases of 2,2 cases of grade 3,no 4,5 cases. Bgroup had 4 cases of Pfirrmann grade 1,24 cases of 2,2 cases of grade 3,no 4,5 cases.Conclusion Inlumbarinterbody fusion,posterior ligament complex can decrease the incidence of adjacent segment degeneration.