Medium-term Clinical Effects Of Dynesys Dynamic Internal Fixation System For Lumbar Degenrative Disease

Objective:To invetigate the Medium-term clinical effects of the dynesys system inaddition to decompression in treatment of lumbar vertebra cataplasia diseases bycomparing the difference of clinical efficacy between Dynesys and lumbar interbodyfusion in treatment of lumbar vertebra cataplasia diseases.Methods:Retrospectively analyze63cases diagnosed degenerative lumbar diseaseunderwent two treatment methods from February2008to August2011.Group A:treated with Dynesys in addition to decompression. Group B: treated with lumbarinterbody fusion in addition to decompression. The group A consisted of twenty-eightpatienis and the group B consisted of thirty-one patienis. The factors consideredincluded the operative time,amount of intraoperative bleeding, pre and post operativeassessment based on pain visual analog scales(VAS),the Oswestry disabilityindex(ODI) and Japanese Orthopaedic Association Scores(JOA),the total exeellentand good ratio of outeome.The postoperative examination has been taken andpostero-anterior radio-grammphs, lateral projection radiogrammphs andflexion-extension radiographs were taken at the final follow-up. The operative timeand blood loss of all patients were observed．Results: All the patients were completed surgery successfully,,fifty-nine patieniswere eventually followed up for a mean of37.4months(range30-54months).The finalvaluation was based on the doeuments of the last fellow up.The two groups hadsignificant differences on operative time,amount of intraoperative bleeding,the groupB higher than the group A(P<0.05).There were no significant diffirences in the painvisual analog scales(VAS),the Oswestry disability index(ODI) and JapaneseOrthopaedic Association Scores(JOA),the total excellent and good ratio ofoutcome(P>0.05).In the two group：VAS, ODI and JOA improved from preoperativeto postoperative(P<0.05).The two groups had significant differences on the range ofmotion (ROM) of instrumented segments between pre and post operative (P<0.05).There were no significant diffirences on the range of motion (ROM) ofproximal adjacent segments between pre and post operative in group A(P>0.05),buton the Contrary in group B(P<0.05).The last fellow up of the two groups, there wassignificant differences on the range of motion (ROM) of instrumented and proximaladjacent segments between pre and post operative in both group (both P<0.05). Therewas significant differences on the range of motion (ROM) of instrumented andproximal adjacent segments between the two group (both P<0.05). Loosening andfracture fixation was not found in the follow-up period.Conclusion：Compared to the segment fusion and fixation,transpedicular dynamicstabilization for the treatment of degenerative lumbar spinal stenosis,have the merit ofminimally invasive,shorter surgical time,little hemorrhage，but their clinical effectwere comparable. Dynesy scould preserve partial ROM of instrumented segments,andin reducing the occurrence of surgical segment degeneration and adjacent segmentaspect, Dynesys dynamic fixed are better than decompression and fusion.