Biomechanical And Clinical Research Of Autogeneous Bone In The Lumbar Interbody Fusion

PartⅠPreparation and Biomechanical Research of Autogeneous Bone Lumbar Interbody Fusion CageObjectiveThe research made animal model building with pig spine. To produce autogeneous bone lumbar interbody fusion cage made by special instrument. To analyze and compare the biomechanical initial stability properties of the lumbar interbody fusion cage with vertebral pedicle screw fixation, PEEK cage with vertebral pedicle screw fixation, so as to provide theoretical basis and experiment guidance in clinical use of autogeneous bone lumbar interbody fusion cage with vertebral pedicle screw fixation in PLIF.Methods1. 12 fresh adult pigs separated the lumbarvertebrae involved 4 vertebrae segments (L1-L4) were obtained. To take the posteroanterior and lateral radiograph, removing muscles tissue carefully with the ligament and disc reserved. Randomly divided these specimens into 2 groups: autogeneous bone lumbar interbody fusion cage with vertebral pedicle screw fixation (experimental group), PEEK cage with vertebral pedicle screw fixation (control group). 2.Resin embedding method and graded facetectomy and discectomy were made to model the types of Spinal Instability. Experimental group used autogeneous bone lumbar interbody fusion cage with vertebral pedicle screw fixation; control group used PEEK cage with vertebral pedicle screw fixation. The 3-dimensional motion of specimens were tested in intacted state, instability state and fusion state, which the flexion, extension, bilateral bending and axial rotation loading were applied to the specimens and the range of motion(ROM) were determined by the 3-dimensional laser scanner. Analyzed the data with SPSS 16.0 software.3. After the 3-dimensional motional stability test finished, the specimens were measured on the MTS testing system.The pullout test was performed on MTS testing system. Recorded the largest pullout force and analyzed data with SPSS 16.0 software.Results1. There was no significant difference in all stability index between two groups in intact state (P>0.05). Compare with intact state,there was significant difference in all stability index in instable state in both groups(P<0.05). After PLIF,there was no significant difference in all stability index between two group(P>0.05).2. In the largest pullout force test of lumbar interbody fusion cage, the mean force of the experimental group was 111.83±9.11N,weaker than 118.173±8.17N that of control group(P>0.05).ConclusionThe produced autogeneous bone lumbar interbody fusion cage with vertebral pedicle screw fixation can provide the good biomechanical initial stability properties. PartⅡApplication of Posterior Lumbar Interbody Fusion(PLIF) with Autogenous Morselized Bone Graft Impaction in Degenerated Lumbar InstabilityObjective:To investigate the clinical feasibility and outcomes of patients for degenerated lumbar instability with foraminal stenosis treated by PLIF with autogenous morselized bone graft impaction.MethodsBetween January 2007 and January 2010,60 consecutive patients seeking PLIF treatment for degenerated lumbar instability with foraminal stenosis in our department were included in this study. All patients were randomized to autogenous morselized bone graft impaction fusion group (n=30) and to PEEK cage fusion group (n=30). There was no significant difference in preoperative general condition between two groups.The imaging and clinical outcome in the two groups were compared.Results:There was no significant difference in operative time , blood loss and walking time between two groups (P>0.05). there were significant difference preoperative and 1 month postoperative (P<0.05), while no significant difference in both groups(P>0.05). The clinical outcomes were determined using a Macnab criteria, which revealed that the excellent and good rate 90.0% in experimental group and 93.3% in control group(P>0.05). Both neuroforamen height and lumbar space height are ameliorated and maintained efficiently, there were significant difference preoperative and 1 month postoperative (P<0.05), while no significant difference postperative and 1 month postoperative in both index (P>0.05).The bony fusion rate was 90.0% in experimental group, 93.3% in control group(P>0.05). ConclusionAutogenous morselized bone graft impaction with pedicle screw fixation in posterior lumbar interbody fusion is a safe ,effective treatment for degenerated lumbar instability, because of its complete decompress,instant stability, reliable bony fusion, low complication rate, and worthy of popularization.