Radiographic effect of osteogenic protein-1（OP-1） on lumbar disc after nucleus pulposus aspiration in rabbits

English Keywords:Intervertebral Disk  Disk Degeneration,Osteogenic Protein-1  Disk image  Aspiration of Nucleus Pulposus

English Abstract:

  【Abstract】 Objective：To investigate the radiographic effect of osteogenic protein-1（OP-1） on lumbar disc after nucleus pulposus aspiration in rabbits.Method：32 Japanese rabbits were randomly divided into 2 weeks，4 weeks，8 weeks and 12 weeks group.All the rabbits′ posterior annulus fibrosus of L3/4 disc were stabbed by 21-gauge hypodermic needle，then some nucleus pulposus tissues were aspirated out.25μl OP-1 were injected into test discs using micro-injection syringe as test group（OP-1 group）.While lumbar 1/2 disc were performed the procedure as lumbar 3/4 and 25μl saline were injected as blank control（Saline group）.2 weeks，4 weeks，8 weeks and12 weeks after operation，lateral X-ray was performed on 8 rabbits and the disc height as well as disc height index（DHI） were measured，and the T2 weighted signal intensity of each group was measured under MRI.Result：Disc height decreased gradually with time passing in both OP-1 group and without significant difference between the two groups，and at each time point，the difference of DHI between two groups was significant（P<0.05）.MRI showed the nucleus pulposus signal intensity in OP-1group was higher than saline group at each time point after operation，which resulted in a significant Thompson score difference（P<0.05） between 2 groups.Conclusion：OP-1 can delay the disc height loss and degrade MRI T2-weighted signal intensity after nucleus pulposus aspiration.