Design and biomechanical test of a novel lumbosacral anterior plate

Objective To design a new lumbosacral anterior plate by statistical analysis for the numerical value of the anatomic structure in Chinese.Methods The numerical value of lumbosacral angle and height of lumbosacral vertebrae,and discus intervertebralis were measured in 350 orthotropia and lateral view X-ray pictures of lumbosacral vertebrae of adult normal individuals.According to the acquired amplitude of lumbosacral vertebrae in Chinese,we designed the modified lumbosacral anterior plate,and then tested the plate in 4 different states of working condition on 8 fresh spinal columns to assay biomechanical data,and the results were compared with those of lumbosacral anterior secure plate(PACH).Results The amplitude of lumbosacral angle were 125 to 135,the heights of anterior border L5 and S1 vertebrae were(27.06±2.30) and(22.3±2.8)mm,the height of L5S1 discus intervertebralis was(8.2±0.3)mm.The flex bias and the compression rigidity had significant deviation for the vertebral column fixed the modified plate [flexation(4.706±0.012)mm,extension(4.549±0.298)mm,lateral bending(5.412±0.384)mm,average value of rigidity in 400 N(105.8±7.6)N/mm] and PACH[flexation(5.241±0.113) mm,extension(5.662±0.246)mm,lateral bending(6.767±0.017)mm,and average value of rigidity(87.4±4.2)N/mm] respectively,with statistical significance among them(P0.05).Conclusion The modified lumbosacral anterior plate system accommodates the anatomic structure of lumbosacral vertebrae in Chinese,possesses conspicuous stability,and is suitable for reconstruction of lumbosacral vertebrae in indicated patients.