Comparative Study Of Clinical Efficacy And Adjacent Segment Degeneration After Dynesys And PLIF For The Treatment Of Lumbar Degenerative Disease

Objective: To compare the clinical efficacy and radiographic outcome ofadjacent segment degeneration between Dynesys system and posterior lumbarinterbody fusion (PLIF) for the treatment of lumbar degenerative disease.Method: This prospective randomized case-controlled study included34patients were treated with Dynesys system fixation and36patients were treatedwith PLIF to treat lumbar degenerative disease from Jan2011to Jan2012. Thevisual analogue scale (VAS) for back and leg pain score, and the Oswestrydisability index (ODI) scores were compared between two groups atpreoperation and postoperation. Routine lumbar MRI test was done atpreoperation and final follow-up, the degeneration of the adjacent segment discwas evaluated according to the Woodend classification; the treatment efficiencywas assessed with Macnab criteria.Results: All the70patients were followed-up for24-33months（mean,28months). In Dynesys group: The mean VAS for back pain improved withstatistical significance, from7.00±0.88preoperatively to2.49±0.88postopera-tively (P<0.01). The mean VAS for leg pain improved with statisticalsignificance, from7.07±0.91preoperatively to2.36±0.86postoperatively (P<0.01). The ODI functional scores significantly improved from55.20±14.07preoperatively to21.35±3.41postoperatively (P<0.01). In PLIF group: themean VAS for back pain improved with statistical significance, from6.30±1.07preoperatively to2.65±1.34postoperatively (P<0.01). The mean VAS for legpain improved with statistical significance, from6.44±0.98preoperatively to2.25±1.56postoperatively (P<0.01). The ODI functional scores significantlyimproved from53.36±12.19preoperatively to23.72±7.39postoperatively(P<0.01). In Dynesys group, mean Woodend score decreased from1.46±0.51preoperatively to1.44±0.49postoperatively at the cranial adjacent segment(P>0.05), and1.50±0.65preoperatively to1.43±0.53postoperatively at thecaudal adjacent segment(P>0.05). In PLIF group, mean Woodend scoreincreased from1.46±0.50preoperatively to1.57±0.62postoperatively at thecranial adjacent segment(P<0.05), and1.56±0.62preoperatively to1.61±0.70postoperatively at the caudal adjacent segment(P>0.05). The excellent andgood rate was88%in Dynesys group, while was81%in PLIF group accordingto Macnab criteria.Conclusion: Dynesys and PLIF have equivalent short-term efficacy for thetreatment of lumbar degenerative disease. The PLIF could acceleratedegeneration of adjacent segment disc. The short-term impact is not obviousabout adjacent segment disc degeneration after Dynesys, the results need to befurther long-term follow-up.