Preparation and in vitro biomechanical analysis of PDLLA Cage following implantation into a goat cervical spine model
10.3969/j.issn.1673-8225.2009.52.001
- VernacularTitle:颈椎植入性融合器PDLLA Cage的制备及置入山羊颈椎后的体外生物力学分析
- Author:
Xiaohui LI
;
Yueming SONG
;
Hong DUAN
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2009;13(52):10211-10217
- CountryChina
- Language:Chinese
-
Abstract:
BACKGROUND:Typical anterior cervical decompression and fusion method has many disadvantages.Cervical fusion cage has obtained satisfactory outcomes,but many problems should be solved.OBJECTIVE:To design a type of PDLLA Cage and to investigate the immediate stability of different fusion methods in a goat cervical spine model following C_(3-4) fusion.DESIGN,TIME AND SETTING:Randomized controlled study was performed at the Laboratory of Biomechanics,Sichuan University from June 2005 to January 2006.MATERIALS:C_(3-4) segment was obtained from a total of 15 adult female 2-year goat corpses.Additional C_(3-4) from 27 adult female 2-year goats was used in biomechanics test.Samples were supplied by the Animal Experimental Center,West China Clinical Medical College,Sichuan University to use in measurement of anatomy parameter and biomechanica test.METHODS:C_(3-4) segment obtained from goat corpse was subjected to X-ray test in an anterior lateral position.In accordance with C_(3-4) mean vertebral height,the angle of C_3 vertebral inferior border and anterior border,the anterior and posterior distance of C_3 vertebral inferior border,as well as the distance of anterior and posterior borders of the middle vertebral body,a type of PDLLA Cage was designed and made,and the biomechanical behavior analysis about the materials was performed.The 27 goat samples were not destroyed following biomechanics test (normal control group),and were assigned to 3 groups,PDLLA Cage group (n=9),titanium alloy Cage group (n=9) and autologous iliac bone group (n=9).Anterior longitudinal ligament was incised at FSU intervertebral space.Following excising the nucleus pulposus,adherent muscle was removed and the whole ligament was remained,as well as the bony terminal plate and cartilage subchondral bone were reserved.PDLLA Cage and titanium alloy Cage were respectively implanted in the cavity of the Cage main body in the PDLLA Cage group and titanium alloy Cage group.The Cage was fixed in the vertebral body using two fixing plates of anterior alar plate with 3.5-mm screw.Autologous cortical iliac bone from three surfaces was implanted in the autologous iliac bone group.MAIN OUTCOME MEASURES:Biomechanics was tested in flexion,extension,axial rotation,and lateral bending using 1,2,3,4 N·m moment of force method.The mean stiffness values and the range of motion were calculated in each group. RESULTS:In every loading mode,the displacement values were statistically significant difference between cage groups (PDLLA Cage group and titanium Cage group) compared with the normal control group (P<0.05);and the displacement of cage groups were lower than that of the autologous tricortical iliac crest bone graft group except for 4 N·m bending loading mode (P<0.05).Posterior extension was significant better in the PDLLA Cage group and titanium alloy Cage group compared with the autologous iliac bone group.Compared with the normal control group,the displacement of posterior extension and lateral bending was lower in the autologous iliac bone group (P<0.05).The stiffness of PDLLA Cage and the titanium Cage group in the flexion loading had no significant difference (P>0.05).In the others loading condition,the titanium Cage group was statistically greatest in all directions (P<0.05).The stiffness of PDLLA Cage was comparable with that of the titanium Cage and was statistically higher than that of the autologous tricortical iliac crest bone graft and intact (P<0.05).CONCLUSION:This type of PDLLA Cage can provide enough primary stability for cervical intervertebral fusion.
